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Posted to commits@hbase.apache.org by zg...@apache.org on 2019/05/17 07:30:26 UTC
[hbase] 01/01: Preparing HBase release 2.2.0RC4;
tagging and updates to CHANGES.md and RELEASENOTES.md
This is an automated email from the ASF dual-hosted git repository.
zghao pushed a commit to tag 2.2.0RC4
in repository https://gitbox.apache.org/repos/asf/hbase.git
commit 7a73fd86c3c1d951e7c8b1323175d184c962c45c
Author: Guanghao Zhang <zg...@apache.org>
AuthorDate: Fri May 17 06:54:23 2019 +0000
Preparing HBase release 2.2.0RC4; tagging and updates to CHANGES.md and RELEASENOTES.md
---
CHANGES.md | 664 +
RELEASENOTES.md | 231066 +++++++++++++++++-
hbase-annotations/pom.xml | 2 +-
hbase-archetypes/hbase-archetype-builder/pom.xml | 2 +-
hbase-archetypes/hbase-client-project/pom.xml | 2 +-
.../hbase-shaded-client-project/pom.xml | 2 +-
hbase-archetypes/pom.xml | 2 +-
hbase-assembly/pom.xml | 2 +-
hbase-build-configuration/pom.xml | 2 +-
hbase-checkstyle/pom.xml | 4 +-
hbase-client/pom.xml | 2 +-
hbase-common/pom.xml | 2 +-
hbase-endpoint/pom.xml | 2 +-
hbase-examples/pom.xml | 2 +-
hbase-external-blockcache/pom.xml | 2 +-
hbase-hadoop-compat/pom.xml | 2 +-
hbase-hadoop2-compat/pom.xml | 2 +-
hbase-http/pom.xml | 2 +-
hbase-it/pom.xml | 2 +-
hbase-mapreduce/pom.xml | 2 +-
hbase-metrics-api/pom.xml | 2 +-
hbase-metrics/pom.xml | 2 +-
hbase-procedure/pom.xml | 2 +-
hbase-protocol-shaded/pom.xml | 2 +-
hbase-protocol/pom.xml | 2 +-
hbase-replication/pom.xml | 2 +-
hbase-resource-bundle/pom.xml | 2 +-
hbase-rest/pom.xml | 2 +-
hbase-rsgroup/pom.xml | 2 +-
hbase-server/pom.xml | 2 +-
hbase-shaded/hbase-shaded-check-invariants/pom.xml | 2 +-
.../hbase-shaded-client-byo-hadoop/pom.xml | 2 +-
hbase-shaded/hbase-shaded-client/pom.xml | 2 +-
hbase-shaded/hbase-shaded-mapreduce/pom.xml | 2 +-
.../pom.xml | 2 +-
hbase-shaded/pom.xml | 2 +-
hbase-shell/pom.xml | 2 +-
hbase-testing-util/pom.xml | 2 +-
hbase-thrift/pom.xml | 2 +-
hbase-zookeeper/pom.xml | 2 +-
pom.xml | 2 +-
41 files changed, 231257 insertions(+), 553 deletions(-)
diff --git a/CHANGES.md b/CHANGES.md
index dce0ba3..8b85944 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -20,6 +20,670 @@
# Be careful doing manual edits in this file. Do not change format
# of release header or remove the below marker. This file is generated.
# DO NOT REMOVE THIS MARKER; FOR INTERPOLATING CHANGES!-->
+## Release 2.2.0 - Unreleased (as of 2019-05-17)
+
+### INCOMPATIBLE CHANGES:
+
+| JIRA | Summary | Priority | Component |
+|:---- |:---- | :--- |:---- |
+| [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks | Major | build, hadoop2 |
+| [HBASE-21082](https://issues.apache.org/jira/browse/HBASE-21082) | Reimplement assign/unassign related procedure metrics | Critical | amv2, metrics |
+| [HBASE-20587](https://issues.apache.org/jira/browse/HBASE-20587) | Replace Jackson with shaded thirdparty gson | Major | dependencies |
+| [HBASE-21727](https://issues.apache.org/jira/browse/HBASE-21727) | Simplify documentation around client timeout | Minor | . |
+| [HBASE-21684](https://issues.apache.org/jira/browse/HBASE-21684) | Throw DNRIOE when connection or rpc client is closed | Major | asyncclient, Client |
+| [HBASE-21792](https://issues.apache.org/jira/browse/HBASE-21792) | Mark HTableMultiplexer as deprecated and remove it in 3.0.0 | Major | Client |
+| [HBASE-21657](https://issues.apache.org/jira/browse/HBASE-21657) | PrivateCellUtil#estimatedSerializedSizeOf has been the bottleneck in 100% scan case. | Major | Performance |
+| [HBASE-21560](https://issues.apache.org/jira/browse/HBASE-21560) | Return a new TableDescriptor for MasterObserver#preModifyTable to allow coprocessor modify the TableDescriptor | Major | Coprocessors |
+| [HBASE-21492](https://issues.apache.org/jira/browse/HBASE-21492) | CellCodec Written To WAL Before It's Verified | Critical | wal |
+| [HBASE-21452](https://issues.apache.org/jira/browse/HBASE-21452) | Illegal character in hbase counters group name | Major | spark |
+| [HBASE-21158](https://issues.apache.org/jira/browse/HBASE-21158) | Empty qualifier cell should not be returned if it does not match QualifierFilter | Critical | Filters |
+| [HBASE-21223](https://issues.apache.org/jira/browse/HBASE-21223) | [amv2] Remove abort\_procedure from shell | Critical | amv2, hbck2, shell |
+| [HBASE-20881](https://issues.apache.org/jira/browse/HBASE-20881) | Introduce a region transition procedure to handle all the state transition for a region | Major | amv2, proc-v2 |
+| [HBASE-20884](https://issues.apache.org/jira/browse/HBASE-20884) | Replace usage of our Base64 implementation with java.util.Base64 | Major | . |
+
+
+### NEW FEATURES:
+
+| JIRA | Summary | Priority | Component |
+|:---- |:---- | :--- |:---- |
+| [HBASE-21815](https://issues.apache.org/jira/browse/HBASE-21815) | Make isTrackingMetrics and getMetrics of ScannerContext public | Minor | . |
+| [HBASE-21926](https://issues.apache.org/jira/browse/HBASE-21926) | Profiler servlet | Major | master, Operability, regionserver |
+| [HBASE-20886](https://issues.apache.org/jira/browse/HBASE-20886) | [Auth] Support keytab login in hbase client | Critical | asyncclient, Client, security |
+| [HBASE-17942](https://issues.apache.org/jira/browse/HBASE-17942) | Disable region splits and merges per table | Major | . |
+| [HBASE-21753](https://issues.apache.org/jira/browse/HBASE-21753) | Support getting the locations for all the replicas of a region | Major | Client |
+| [HBASE-20636](https://issues.apache.org/jira/browse/HBASE-20636) | Introduce two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED | Major | HFile, regionserver, Scanners |
+| [HBASE-20649](https://issues.apache.org/jira/browse/HBASE-20649) | Validate HFiles do not have PREFIX\_TREE DataBlockEncoding | Minor | Operability, tooling |
+
+
+### IMPROVEMENTS:
+
+| JIRA | Summary | Priority | Component |
+|:---- |:---- | :--- |:---- |
+| [HBASE-20305](https://issues.apache.org/jira/browse/HBASE-20305) | Add option to SyncTable that skip deletes on target cluster | Minor | mapreduce |
+| [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | Dump replication queue should show list of wal files ordered chronologically | Major | Replication, tooling |
+| [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | Formatting issues in administration section of book | Minor | community, documentation |
+| [HBASE-21658](https://issues.apache.org/jira/browse/HBASE-21658) | Should get the meta replica number from zk instead of config at client side | Critical | Client |
+| [HBASE-22365](https://issues.apache.org/jira/browse/HBASE-22365) | Region may be opened on two RegionServers | Blocker | amv2 |
+| [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | Remove extra/useless + | Trivial | . |
+| [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | Upgrade com.yammer.metrics dependency | Major | dependencies |
+| [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | Change rubocop configuration for method length | Minor | community, shell |
+| [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | Fix Markdown for "Voting on Release Candidates" in book | Minor | community, documentation |
+| [HBASE-22109](https://issues.apache.org/jira/browse/HBASE-22109) | Update hbase shaded content checker after guava update in hadoop branch-3.0 to 27.0-jre | Minor | . |
+| [HBASE-22087](https://issues.apache.org/jira/browse/HBASE-22087) | Update LICENSE/shading for the dependencies from the latest Hadoop trunk | Minor | hadoop3 |
+| [HBASE-22341](https://issues.apache.org/jira/browse/HBASE-22341) | Add explicit guidelines for removing deprecations in book | Major | API, community, documentation |
+| [HBASE-22225](https://issues.apache.org/jira/browse/HBASE-22225) | Profiler tab on Master/RS UI not working w/o comprehensive message | Minor | UI |
+| [HBASE-22291](https://issues.apache.org/jira/browse/HBASE-22291) | Fix recovery of recovered.edits files under root dir | Major | . |
+| [HBASE-22283](https://issues.apache.org/jira/browse/HBASE-22283) | Print row and table information when failed to get region location | Major | Client, logging |
+| [HBASE-22296](https://issues.apache.org/jira/browse/HBASE-22296) | Remove TestFromClientSide.testGetStartEndKeysWithRegionReplicas | Major | test |
+| [HBASE-22250](https://issues.apache.org/jira/browse/HBASE-22250) | The same constants used in many places should be placed in constant classes | Minor | Client, conf, regionserver |
+| [HBASE-20586](https://issues.apache.org/jira/browse/HBASE-20586) | SyncTable tool: Add support for cross-realm remote clusters | Major | mapreduce, Operability, Replication |
+| [HBASE-21257](https://issues.apache.org/jira/browse/HBASE-21257) | misspelled words.[occured -\> occurred] | Trivial | . |
+| [HBASE-22193](https://issues.apache.org/jira/browse/HBASE-22193) | Add backoff when region failed open too many times | Major | . |
+| [HBASE-22188](https://issues.apache.org/jira/browse/HBASE-22188) | Make TestSplitMerge more stable | Major | test |
+| [HBASE-22097](https://issues.apache.org/jira/browse/HBASE-22097) | Modify the description of split command in shell | Trivial | shell |
+| [HBASE-21964](https://issues.apache.org/jira/browse/HBASE-21964) | unset Quota by Throttle Type | Major | master |
+| [HBASE-22093](https://issues.apache.org/jira/browse/HBASE-22093) | Combine TestRestoreSnapshotFromClientWithRegionReplicas to CloneSnapshotFromClientAfterSplittingRegionTestBase#testCloneSnapshotAfterSplittingRegion | Major | . |
+| [HBASE-22009](https://issues.apache.org/jira/browse/HBASE-22009) | Improve RSGroupInfoManagerImpl#getDefaultServers() | Minor | rsgroup |
+| [HBASE-22032](https://issues.apache.org/jira/browse/HBASE-22032) | KeyValue validation should check for null byte array | Major | . |
+| [HBASE-21667](https://issues.apache.org/jira/browse/HBASE-21667) | Move to latest ASF Parent POM | Minor | build |
+| [HBASE-21810](https://issues.apache.org/jira/browse/HBASE-21810) | bulkload support set hfile compression on client | Major | mapreduce |
+| [HBASE-21987](https://issues.apache.org/jira/browse/HBASE-21987) | Simplify RSGroupInfoManagerImpl#flushConfig() for offline mode | Minor | rsgroup |
+| [HBASE-21871](https://issues.apache.org/jira/browse/HBASE-21871) | Support to specify a peer table name in VerifyReplication tool | Major | . |
+| [HBASE-21255](https://issues.apache.org/jira/browse/HBASE-21255) | [acl] Refactor TablePermission into three classes (Global, Namespace, Table) | Major | . |
+| [HBASE-21410](https://issues.apache.org/jira/browse/HBASE-21410) | A helper page that help find all problematic regions and procedures | Major | . |
+| [HBASE-20734](https://issues.apache.org/jira/browse/HBASE-20734) | Colocate recovered edits directory with hbase.wal.dir | Major | MTTR, Recovery, wal |
+| [HBASE-20401](https://issues.apache.org/jira/browse/HBASE-20401) | Make \`MAX\_WAIT\` and \`waitIfNotFinished\` in CleanerContext configurable | Minor | master |
+| [HBASE-21481](https://issues.apache.org/jira/browse/HBASE-21481) | [acl] Superuser's permissions should not be granted or revoked by any non-su global admin | Major | . |
+| [HBASE-21967](https://issues.apache.org/jira/browse/HBASE-21967) | Split TestServerCrashProcedure and TestServerCrashProcedureWithReplicas | Major | . |
+| [HBASE-21867](https://issues.apache.org/jira/browse/HBASE-21867) | Support multi-threads in HFileArchiver | Major | . |
+| [HBASE-21932](https://issues.apache.org/jira/browse/HBASE-21932) | Use Runtime.getRuntime().halt to terminate regionserver when abort timeout | Major | . |
+| [HBASE-21875](https://issues.apache.org/jira/browse/HBASE-21875) | Change the retry logic in RSProcedureDispatcher to 'retry by default, only if xxx' | Major | proc-v2 |
+| [HBASE-21780](https://issues.apache.org/jira/browse/HBASE-21780) | Avoid a wide line on the RegionServer webUI for many ZooKeeper servers | Minor | UI, Usability |
+| [HBASE-21636](https://issues.apache.org/jira/browse/HBASE-21636) | Enhance the shell scan command to support missing scanner specifications like ReadType, IsolationLevel etc. | Major | shell |
+| [HBASE-21857](https://issues.apache.org/jira/browse/HBASE-21857) | Do not need to check clusterKey if replicationEndpoint is provided when adding a peer | Major | . |
+| [HBASE-21201](https://issues.apache.org/jira/browse/HBASE-21201) | Support to run VerifyReplication MR tool without peerid | Major | hbase-operator-tools |
+| [HBASE-21816](https://issues.apache.org/jira/browse/HBASE-21816) | Print source cluster replication config directory | Trivial | Replication |
+| [HBASE-19616](https://issues.apache.org/jira/browse/HBASE-19616) | Review of LogCleaner Class | Minor | . |
+| [HBASE-21830](https://issues.apache.org/jira/browse/HBASE-21830) | Backport HBASE-20577 (Make Log Level page design consistent with the design of other pages in UI) to branch-2 | Major | UI, Usability |
+| [HBASE-21833](https://issues.apache.org/jira/browse/HBASE-21833) | Use NettyAsyncFSWALConfigHelper.setEventLoopConfig to prevent creating too many netty event loop when executing TestHRegion | Minor | test |
+| [HBASE-21634](https://issues.apache.org/jira/browse/HBASE-21634) | Print error message when user uses unacceptable values for LIMIT while setting quotas. | Minor | . |
+| [HBASE-21789](https://issues.apache.org/jira/browse/HBASE-21789) | Rewrite MetaTableAccessor.multiMutate with Table.coprocessorService | Major | Client, Coprocessors |
+| [HBASE-21689](https://issues.apache.org/jira/browse/HBASE-21689) | Make table/namespace specific current quota info available in shell(describe\_namespace & describe) | Minor | . |
+| [HBASE-20215](https://issues.apache.org/jira/browse/HBASE-20215) | Rename CollectionUtils to ConcurrentMapUtils | Trivial | . |
+| [HBASE-21720](https://issues.apache.org/jira/browse/HBASE-21720) | metric to measure how actions are distributed to servers within a MultiAction | Minor | Client, metrics, monitoring |
+| [HBASE-21595](https://issues.apache.org/jira/browse/HBASE-21595) | Print thread's information and stack traces when RS is aborting forcibly | Minor | regionserver |
+| [HBASE-20209](https://issues.apache.org/jira/browse/HBASE-20209) | Do Not Use Both Map containsKey and get Methods in Replication Sink | Trivial | Replication |
+| [HBASE-21712](https://issues.apache.org/jira/browse/HBASE-21712) | Make submit-patch.py python3 compatible | Minor | tooling |
+| [HBASE-21590](https://issues.apache.org/jira/browse/HBASE-21590) | Optimize trySkipToNextColumn in StoreScanner a bit | Critical | Performance, Scanners |
+| [HBASE-21297](https://issues.apache.org/jira/browse/HBASE-21297) | ModifyTableProcedure can throw TNDE instead of IOE in case of REGION\_REPLICATION change | Minor | . |
+| [HBASE-21700](https://issues.apache.org/jira/browse/HBASE-21700) | Simplify the implementation of RSGroupInfoManagerImpl | Major | rsgroup |
+| [HBASE-21694](https://issues.apache.org/jira/browse/HBASE-21694) | Add append\_peer\_exclude\_tableCFs and remove\_peer\_exclude\_tableCFs shell commands | Major | . |
+| [HBASE-21645](https://issues.apache.org/jira/browse/HBASE-21645) | Perform sanity check and disallow table creation/modification with region replication \< 1 | Minor | . |
+| [HBASE-21360](https://issues.apache.org/jira/browse/HBASE-21360) | Disable printing of stack-trace in shell for quotas | Minor | shell |
+| [HBASE-21662](https://issues.apache.org/jira/browse/HBASE-21662) | Add append\_peer\_exclude\_namespaces and remove\_peer\_exclude\_namespaces shell commands | Major | . |
+| [HBASE-21659](https://issues.apache.org/jira/browse/HBASE-21659) | Avoid to load duplicate coprocessors in system config and table descriptor | Minor | . |
+| [HBASE-21642](https://issues.apache.org/jira/browse/HBASE-21642) | CopyTable by reading snapshot and bulkloading will save a lot of time. | Major | . |
+| [HBASE-21643](https://issues.apache.org/jira/browse/HBASE-21643) | Introduce two new region coprocessor method and deprecated postMutationBeforeWAL | Major | . |
+| [HBASE-21640](https://issues.apache.org/jira/browse/HBASE-21640) | Remove the TODO when increment zero | Major | . |
+| [HBASE-21631](https://issues.apache.org/jira/browse/HBASE-21631) | list\_quotas should print human readable values for LIMIT | Minor | shell |
+| [HBASE-21635](https://issues.apache.org/jira/browse/HBASE-21635) | Use maven enforcer to ban imports from illegal packages | Major | build |
+| [HBASE-21514](https://issues.apache.org/jira/browse/HBASE-21514) | Refactor CacheConfig | Major | . |
+| [HBASE-21520](https://issues.apache.org/jira/browse/HBASE-21520) | TestMultiColumnScanner cost long time when using ROWCOL bloom type | Major | test |
+| [HBASE-21554](https://issues.apache.org/jira/browse/HBASE-21554) | Show replication endpoint classname for replication peer on master web UI | Minor | UI |
+| [HBASE-21549](https://issues.apache.org/jira/browse/HBASE-21549) | Add shell command for serial replication peer | Major | . |
+| [HBASE-21283](https://issues.apache.org/jira/browse/HBASE-21283) | Add new shell command 'rit' for listing regions in transition | Minor | Operability, shell |
+| [HBASE-21567](https://issues.apache.org/jira/browse/HBASE-21567) | Allow overriding configs starting up the shell | Major | shell |
+| [HBASE-21413](https://issues.apache.org/jira/browse/HBASE-21413) | Empty meta log doesn't get split when restart whole cluster | Major | . |
+| [HBASE-21524](https://issues.apache.org/jira/browse/HBASE-21524) | Unnecessary DEBUG log in ConnectionImplementation#isTableEnabled | Major | Client |
+| [HBASE-21511](https://issues.apache.org/jira/browse/HBASE-21511) | Remove in progress snapshot check in SnapshotFileCache#getUnreferencedFiles | Minor | snapshots |
+| [HBASE-21480](https://issues.apache.org/jira/browse/HBASE-21480) | Taking snapshot when RS crashes prevent we bring the regions online | Major | snapshots |
+| [HBASE-21485](https://issues.apache.org/jira/browse/HBASE-21485) | Add more debug logs for remote procedure execution | Major | proc-v2 |
+| [HBASE-21328](https://issues.apache.org/jira/browse/HBASE-21328) | add HBASE\_DISABLE\_HADOOP\_CLASSPATH\_LOOKUP switch to hbase-env.sh | Minor | documentation, Operability |
+| [HBASE-19682](https://issues.apache.org/jira/browse/HBASE-19682) | Use Collections.emptyList() For Empty List Values | Minor | . |
+| [HBASE-21388](https://issues.apache.org/jira/browse/HBASE-21388) | No need to instantiate MemStoreLAB for master which not carry table | Major | . |
+| [HBASE-21325](https://issues.apache.org/jira/browse/HBASE-21325) | Force to terminate regionserver when abort hang in somewhere | Major | . |
+| [HBASE-21385](https://issues.apache.org/jira/browse/HBASE-21385) | HTable.delete request use rpc call directly instead of AsyncProcess | Major | . |
+| [HBASE-21318](https://issues.apache.org/jira/browse/HBASE-21318) | Make RefreshHFilesClient runnable | Minor | HFile |
+| [HBASE-21263](https://issues.apache.org/jira/browse/HBASE-21263) | Mention compression algorithm along with other storefile details | Minor | . |
+| [HBASE-21290](https://issues.apache.org/jira/browse/HBASE-21290) | No need to instantiate BlockCache for master which not carry table | Major | . |
+| [HBASE-21256](https://issues.apache.org/jira/browse/HBASE-21256) | Improve IntegrationTestBigLinkedList for testing huge data | Major | integration tests |
+| [HBASE-21251](https://issues.apache.org/jira/browse/HBASE-21251) | Refactor RegionMover | Major | Operability |
+| [HBASE-21303](https://issues.apache.org/jira/browse/HBASE-21303) | [shell] clear\_deadservers with no args fails | Major | . |
+| [HBASE-21098](https://issues.apache.org/jira/browse/HBASE-21098) | Improve Snapshot Performance with Temporary Snapshot Directory when rootDir on S3 | Major | . |
+| [HBASE-21299](https://issues.apache.org/jira/browse/HBASE-21299) | List counts of actual region states in master UI tables section | Major | UI |
+| [HBASE-21289](https://issues.apache.org/jira/browse/HBASE-21289) | Remove the log "'hbase.regionserver.maxlogs' was deprecated." in AbstractFSWAL | Minor | . |
+| [HBASE-21185](https://issues.apache.org/jira/browse/HBASE-21185) | WALPrettyPrinter: Additional useful info to be printed by wal printer tool, for debugability purposes | Minor | Operability |
+| [HBASE-21103](https://issues.apache.org/jira/browse/HBASE-21103) | nightly test cache of yetus install needs to be more thorough in verification | Major | test |
+| [HBASE-21207](https://issues.apache.org/jira/browse/HBASE-21207) | Add client side sorting functionality in master web UI for table and region server details. | Minor | master, monitoring, UI, Usability |
+| [HBASE-20857](https://issues.apache.org/jira/browse/HBASE-20857) | JMX - add Balancer status = enabled / disabled | Major | API, master, metrics, REST, tooling, Usability |
+| [HBASE-21164](https://issues.apache.org/jira/browse/HBASE-21164) | reportForDuty to spew less log if master is initializing | Minor | regionserver |
+| [HBASE-21204](https://issues.apache.org/jira/browse/HBASE-21204) | NPE when scan raw DELETE\_FAMILY\_VERSION and codec is not set | Major | . |
+| [HBASE-20307](https://issues.apache.org/jira/browse/HBASE-20307) | LoadTestTool prints too much zookeeper logging | Minor | tooling |
+| [HBASE-21155](https://issues.apache.org/jira/browse/HBASE-21155) | Save on a few log strings and some churn in wal splitter by skipping out early if no logs in dir | Trivial | . |
+| [HBASE-21129](https://issues.apache.org/jira/browse/HBASE-21129) | Clean up duplicate codes in #equals and #hashCode methods of Filter | Minor | Filters |
+| [HBASE-21157](https://issues.apache.org/jira/browse/HBASE-21157) | Split TableInputFormatScan to individual tests | Minor | test |
+| [HBASE-21107](https://issues.apache.org/jira/browse/HBASE-21107) | add a metrics for netty direct memory | Minor | IPC/RPC |
+| [HBASE-21153](https://issues.apache.org/jira/browse/HBASE-21153) | Shaded client jars should always build in relevant phase to avoid confusion | Major | build |
+| [HBASE-21126](https://issues.apache.org/jira/browse/HBASE-21126) | Add ability for HBase Canary to ignore a configurable number of ZooKeeper down nodes | Minor | canary, Zookeeper |
+| [HBASE-20749](https://issues.apache.org/jira/browse/HBASE-20749) | Upgrade our use of checkstyle to 8.6+ | Minor | build, community |
+| [HBASE-21071](https://issues.apache.org/jira/browse/HBASE-21071) | HBaseTestingUtility::startMiniCluster() to use builder pattern | Major | test |
+| [HBASE-20387](https://issues.apache.org/jira/browse/HBASE-20387) | flaky infrastructure should work for all branches | Critical | test |
+| [HBASE-20469](https://issues.apache.org/jira/browse/HBASE-20469) | Directory used for sidelining old recovered edits files should be made configurable | Minor | . |
+| [HBASE-20979](https://issues.apache.org/jira/browse/HBASE-20979) | Flaky test reporting should specify what JSON it needs and handle HTTP errors | Minor | test |
+| [HBASE-20985](https://issues.apache.org/jira/browse/HBASE-20985) | add two attributes when we do normalization | Major | . |
+| [HBASE-20965](https://issues.apache.org/jira/browse/HBASE-20965) | Separate region server report requests to new handlers | Major | Performance |
+| [HBASE-20845](https://issues.apache.org/jira/browse/HBASE-20845) | Support set the consistency for Gets and Scans in thrift2 | Major | Thrift |
+| [HBASE-20986](https://issues.apache.org/jira/browse/HBASE-20986) | Separate the config of block size when we do log splitting and write Hlog | Major | . |
+| [HBASE-19036](https://issues.apache.org/jira/browse/HBASE-19036) | Add action in Chaos Monkey to restart Active Namenode | Minor | . |
+| [HBASE-20856](https://issues.apache.org/jira/browse/HBASE-20856) | PITA having to set WAL provider in two places | Minor | Operability, wal |
+| [HBASE-20935](https://issues.apache.org/jira/browse/HBASE-20935) | HStore.removeCompactedFiles should log in case it is unable to delete a file | Minor | . |
+| [HBASE-20873](https://issues.apache.org/jira/browse/HBASE-20873) | Update doc for Endpoint-based Export | Minor | documentation |
+| [HBASE-20672](https://issues.apache.org/jira/browse/HBASE-20672) | New metrics ReadRequestRate and WriteRequestRate | Minor | metrics |
+| [HBASE-20617](https://issues.apache.org/jira/browse/HBASE-20617) | Upgrade/remove jetty-jsp | Minor | . |
+| [HBASE-20396](https://issues.apache.org/jira/browse/HBASE-20396) | Remove redundant MBean from thrift JMX | Major | Thrift |
+| [HBASE-20357](https://issues.apache.org/jira/browse/HBASE-20357) | AccessControlClient API Enhancement | Major | security |
+
+
+### BUG FIXES:
+
+| JIRA | Summary | Priority | Component |
+|:---- |:---- | :--- |:---- |
+| [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements | Major | Coprocessors, metrics |
+| [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | Update hadoop check versions for hadoop3 in hbase-personality | Major | build |
+| [HBASE-22424](https://issues.apache.org/jira/browse/HBASE-22424) | Interactions in RSGroup test classes will cause TestRSGroupsAdmin2.testMoveServersAndTables and TestRSGroupsBalance.testGroupBalance flaky | Major | rsgroup |
+| [HBASE-22404](https://issues.apache.org/jira/browse/HBASE-22404) | Open/Close region request may be executed twice when master restart | Major | . |
+| [HBASE-22274](https://issues.apache.org/jira/browse/HBASE-22274) | Cell size limit check on append should consider cell's previous size. | Minor | . |
+| [HBASE-21800](https://issues.apache.org/jira/browse/HBASE-21800) | RegionServer aborted due to NPE from MetaTableMetrics coprocessor | Critical | Coprocessors, meta, metrics, Operability |
+| [HBASE-22072](https://issues.apache.org/jira/browse/HBASE-22072) | High read/write intensive regions may cause long crash recovery | Major | Performance, Recovery |
+| [HBASE-22324](https://issues.apache.org/jira/browse/HBASE-22324) | loss a mass of data when the sequenceId of cells greater than Integer.Max, because MemStoreMergerSegmentsIterator can not merge segments | Blocker | in-memory-compaction |
+| [HBASE-21777](https://issues.apache.org/jira/browse/HBASE-21777) | "Tune compaction throughput" debug messages even when nothing has changed | Trivial | Compaction |
+| [HBASE-22360](https://issues.apache.org/jira/browse/HBASE-22360) | Abort timer doesn't set when abort is called during graceful shutdown process | Major | regionserver |
+| [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | Change rubocop config for max line length of 100 | Minor | community, shell |
+| [HBASE-21467](https://issues.apache.org/jira/browse/HBASE-21467) | Fix flaky test TestCoprocessorClassLoader.testCleanupOldJars | Minor | . |
+| [HBASE-22312](https://issues.apache.org/jira/browse/HBASE-22312) | Hadoop 3 profile for hbase-shaded-mapreduce should like mapreduce as a provided dependency | Major | mapreduce, shading |
+| [HBASE-22314](https://issues.apache.org/jira/browse/HBASE-22314) | shaded byo-hadoop client should list needed hadoop modules as provided scope to avoid inclusion of unnecessary transitive depednencies | Major | hadoop2, hadoop3, shading |
+| [HBASE-22047](https://issues.apache.org/jira/browse/HBASE-22047) | LeaseException in Scan should be retired | Major | Client, Scanners |
+| [HBASE-22343](https://issues.apache.org/jira/browse/HBASE-22343) | Make procedure retry interval configurable in test | Major | amv2, test |
+| [HBASE-22190](https://issues.apache.org/jira/browse/HBASE-22190) | SnapshotFileCache may fail to load the correct snapshot file list when there is an on-going snapshot operation | Blocker | snapshots |
+| [HBASE-22354](https://issues.apache.org/jira/browse/HBASE-22354) | master never sets abortRequested, and thus abort timeout doesn't work for it | Major | . |
+| [HBASE-22350](https://issues.apache.org/jira/browse/HBASE-22350) | Rewrite TestClientOperationTimeout so we do not timeout when creating table | Major | test |
+| [HBASE-22340](https://issues.apache.org/jira/browse/HBASE-22340) | Corrupt KeyValue is silently ignored | Critical | wal |
+| [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS | Minor | . |
+| [HBASE-22236](https://issues.apache.org/jira/browse/HBASE-22236) | AsyncNonMetaRegionLocator should not cache HRegionLocation with null location | Major | asyncclient |
+| [HBASE-22086](https://issues.apache.org/jira/browse/HBASE-22086) | space quota issue: deleting snapshot doesn't update the usage of table | Minor | . |
+| [HBASE-22298](https://issues.apache.org/jira/browse/HBASE-22298) | branch-2.2 nightly fails "[ForOverride] Method annotated @ForOverride must have protected or package-private visibility" | Major | . |
+| [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | PreemptiveFastFailInterceptor clean repeatedFailuresMap issue | Blocker | . |
+| [HBASE-22230](https://issues.apache.org/jira/browse/HBASE-22230) | REST Server drops connection on long scans | Major | . |
+| [HBASE-22200](https://issues.apache.org/jira/browse/HBASE-22200) | WALSplitter.hasRecoveredEdits should use same FS instance from WAL region dir | Major | wal |
+| [HBASE-22286](https://issues.apache.org/jira/browse/HBASE-22286) | License handling incorrectly lists CDDL/GPLv2+CE as safe to not aggregate | Critical | build, community |
+| [HBASE-22282](https://issues.apache.org/jira/browse/HBASE-22282) | Should deal with error in the callback of RawAsyncHBaseAdmin.splitRegion methods | Major | Admin, asyncclient |
+| [HBASE-22278](https://issues.apache.org/jira/browse/HBASE-22278) | RawAsyncHBaseAdmin should not use cached region location | Major | Admin, asyncclient |
+| [HBASE-22222](https://issues.apache.org/jira/browse/HBASE-22222) | Site build fails after hbase-thirdparty upgrade | Blocker | website |
+| [HBASE-22249](https://issues.apache.org/jira/browse/HBASE-22249) | Rest Server throws NoClassDefFoundError with Java 11 (run-time) | Major | . |
+| [HBASE-22235](https://issues.apache.org/jira/browse/HBASE-22235) | OperationStatus.{SUCCESS\|FAILURE\|NOT\_RUN} are not visible to 3rd party coprocessors | Major | Coprocessors |
+| [HBASE-22207](https://issues.apache.org/jira/browse/HBASE-22207) | Fix flakey TestAssignmentManager.testAssignSocketTimeout | Major | test |
+| [HBASE-22202](https://issues.apache.org/jira/browse/HBASE-22202) | Fix new findbugs issues after we upgrade hbase-thirdparty dependencies | Major | findbugs |
+| [HBASE-22144](https://issues.apache.org/jira/browse/HBASE-22144) | MultiRowRangeFilter does not work with reversed scans | Critical | Filters, Scanners |
+| [HBASE-22198](https://issues.apache.org/jira/browse/HBASE-22198) | Fix flakey TestAsyncTableGetMultiThreaded | Major | test |
+| [HBASE-22185](https://issues.apache.org/jira/browse/HBASE-22185) | RAMQueueEntry#writeToCache should freeBlock if any exception encountered instead of the IOException catch block | Major | . |
+| [HBASE-22163](https://issues.apache.org/jira/browse/HBASE-22163) | Should not archive the compacted store files when region warmup | Blocker | . |
+| [HBASE-22178](https://issues.apache.org/jira/browse/HBASE-22178) | Introduce a createTableAsync with TableDescriptor method in Admin | Major | Admin |
+| [HBASE-22180](https://issues.apache.org/jira/browse/HBASE-22180) | Make TestBlockEvictionFromClient.testBlockRefCountAfterSplits more stable | Major | test |
+| [HBASE-22179](https://issues.apache.org/jira/browse/HBASE-22179) | Fix RawAsyncHBaseAdmin.getCompactionState | Major | Admin, asyncclient |
+| [HBASE-22177](https://issues.apache.org/jira/browse/HBASE-22177) | Do not recreate IOException in RawAsyncHBaseAdmin.adminCall | Major | Admin, asyncclient |
+| [HBASE-22070](https://issues.apache.org/jira/browse/HBASE-22070) | Checking restoreDir in RestoreSnapshotHelper | Minor | snapshots |
+| [HBASE-20912](https://issues.apache.org/jira/browse/HBASE-20912) | Add import order config in dev support for eclipse | Major | . |
+| [HBASE-22133](https://issues.apache.org/jira/browse/HBASE-22133) | Forward port HBASE-22073 "/rits.jsp throws an exception if no procedure" to branch-2.2+ | Major | UI |
+| [HBASE-20911](https://issues.apache.org/jira/browse/HBASE-20911) | correct Swtich/case indentation in formatter template for eclipse | Major | . |
+| [HBASE-21688](https://issues.apache.org/jira/browse/HBASE-21688) | Address WAL filesystem issues | Major | Filesystem Integration, wal |
+| [HBASE-22121](https://issues.apache.org/jira/browse/HBASE-22121) | AsyncAdmin can not deal with non default meta replica | Major | Admin, asyncclient, Client |
+| [HBASE-22115](https://issues.apache.org/jira/browse/HBASE-22115) | HBase RPC aspires to grow an infinite tree of trace scopes; some other places are also unsafe | Critical | . |
+| [HBASE-22123](https://issues.apache.org/jira/browse/HBASE-22123) | REST gateway reports Insufficient permissions exceptions as 404 Not Found | Minor | REST |
+| [HBASE-21135](https://issues.apache.org/jira/browse/HBASE-21135) | Build fails on windows as it fails to parse windows path during license check | Major | build |
+| [HBASE-21781](https://issues.apache.org/jira/browse/HBASE-21781) | list\_deadservers elapsed time is incorrect | Major | shell |
+| [HBASE-22100](https://issues.apache.org/jira/browse/HBASE-22100) | False positive for error prone warnings in pre commit job | Minor | build |
+| [HBASE-22098](https://issues.apache.org/jira/browse/HBASE-22098) | Backport HBASE-18667 "Disable error-prone for hbase-protocol-shaded" to branch-2 | Major | build |
+| [HBASE-20662](https://issues.apache.org/jira/browse/HBASE-20662) | Increasing space quota on a violated table does not remove SpaceViolationPolicy.DISABLE enforcement | Major | . |
+| [HBASE-22057](https://issues.apache.org/jira/browse/HBASE-22057) | Impose upper-bound on size of ZK ops sent in a single multi() | Major | . |
+| [HBASE-22074](https://issues.apache.org/jira/browse/HBASE-22074) | Should use procedure store to persist the state in reportRegionStateTransition | Blocker | amv2, proc-v2 |
+| [HBASE-21619](https://issues.apache.org/jira/browse/HBASE-21619) | Fix warning message caused by incorrect ternary operator evaluation | Trivial | . |
+| [HBASE-22095](https://issues.apache.org/jira/browse/HBASE-22095) | Taking a snapshot fails in local mode | Major | . |
+| [HBASE-22061](https://issues.apache.org/jira/browse/HBASE-22061) | SplitTableRegionProcedure should hold the lock of its daughter regions | Major | . |
+| [HBASE-22045](https://issues.apache.org/jira/browse/HBASE-22045) | Mutable range histogram reports incorrect outliers | Major | . |
+| [HBASE-21736](https://issues.apache.org/jira/browse/HBASE-21736) | Remove the server from online servers before scheduling SCP for it in hbck | Major | hbck2, test |
+| [HBASE-22011](https://issues.apache.org/jira/browse/HBASE-22011) | ThriftUtilities.getFromThrift should set filter when not set columns | Major | . |
+| [HBASE-21990](https://issues.apache.org/jira/browse/HBASE-21990) | puppycrawl checkstyle dtds 404... moved to sourceforge | Major | build |
+| [HBASE-22010](https://issues.apache.org/jira/browse/HBASE-22010) | docs on upgrade from 2.0,2.1 -\> 2.2 renders incorrectly | Minor | documentation |
+| [HBASE-22006](https://issues.apache.org/jira/browse/HBASE-22006) | Fix branch-2.1 findbugs warning; causes nightly show as failed. | Major | . |
+| [HBASE-21960](https://issues.apache.org/jira/browse/HBASE-21960) | RESTServletContainer not configured for REST Jetty server | Blocker | REST |
+| [HBASE-21915](https://issues.apache.org/jira/browse/HBASE-21915) | FileLink$FileLinkInputStream doesn't implement CanUnbuffer | Major | Filesystem Integration |
+| [HBASE-21565](https://issues.apache.org/jira/browse/HBASE-21565) | Delete dead server from dead server list too early leads to concurrent Server Crash Procedures(SCP) for a same server | Critical | . |
+| [HBASE-21740](https://issues.apache.org/jira/browse/HBASE-21740) | NPE happens while shutdown the RS | Major | . |
+| [HBASE-21866](https://issues.apache.org/jira/browse/HBASE-21866) | Do not move the table to null rsgroup when creating an existing table | Major | proc-v2, rsgroup |
+| [HBASE-21983](https://issues.apache.org/jira/browse/HBASE-21983) | Should track the scan metrics in AsyncScanSingleRegionRpcRetryingCaller if scan metrics is enabled | Major | asyncclient, Client |
+| [HBASE-21980](https://issues.apache.org/jira/browse/HBASE-21980) | Fix typo in AbstractTestAsyncTableRegionReplicasRead | Major | test |
+| [HBASE-21487](https://issues.apache.org/jira/browse/HBASE-21487) | Concurrent modify table ops can lead to unexpected results | Major | . |
+| [HBASE-20724](https://issues.apache.org/jira/browse/HBASE-20724) | Sometimes some compacted storefiles are still opened after region failover | Critical | . |
+| [HBASE-21961](https://issues.apache.org/jira/browse/HBASE-21961) | Infinite loop in AsyncNonMetaRegionLocator if there is only one region and we tried to locate before a non empty row | Critical | asyncclient, Client |
+| [HBASE-21943](https://issues.apache.org/jira/browse/HBASE-21943) | The usage of RegionLocations.mergeRegionLocations is wrong for async client | Critical | asyncclient, Client |
+| [HBASE-21947](https://issues.apache.org/jira/browse/HBASE-21947) | TestShell is broken after we remove the jackson dependencies | Major | dependencies, shell |
+| [HBASE-21942](https://issues.apache.org/jira/browse/HBASE-21942) | [UI] requests per second is incorrect in rsgroup page(rsgroup.jsp) | Minor | . |
+| [HBASE-21922](https://issues.apache.org/jira/browse/HBASE-21922) | BloomContext#sanityCheck may failed when use ROWPREFIX\_DELIMITED bloom filter | Major | . |
+| [HBASE-21929](https://issues.apache.org/jira/browse/HBASE-21929) | The checks at the end of TestRpcClientLeaks are not executed | Major | test |
+| [HBASE-21938](https://issues.apache.org/jira/browse/HBASE-21938) | Add a new ClusterMetrics.Option SERVERS\_NAME to only return the live region servers's name without metrics | Major | . |
+| [HBASE-21928](https://issues.apache.org/jira/browse/HBASE-21928) | Deprecated HConstants.META\_QOS | Major | Client, rpc |
+| [HBASE-21899](https://issues.apache.org/jira/browse/HBASE-21899) | Fix missing variables in slf4j Logger | Trivial | logging |
+| [HBASE-21910](https://issues.apache.org/jira/browse/HBASE-21910) | The nonce implementation is wrong for AsyncTable | Critical | asyncclient, Client |
+| [HBASE-21900](https://issues.apache.org/jira/browse/HBASE-21900) | Infinite loop in AsyncMetaRegionLocator if we can not get the location for meta | Major | asyncclient, Client |
+| [HBASE-21890](https://issues.apache.org/jira/browse/HBASE-21890) | Use execute instead of submit to submit a task in RemoteProcedureDispatcher | Critical | proc-v2 |
+| [HBASE-21889](https://issues.apache.org/jira/browse/HBASE-21889) | Use thrift 0.12.0 when build thrift by compile-thrift profile | Major | . |
+| [HBASE-21785](https://issues.apache.org/jira/browse/HBASE-21785) | master reports open regions as RITs and also messes up rit age metric | Major | . |
+| [HBASE-21854](https://issues.apache.org/jira/browse/HBASE-21854) | Race condition in TestProcedureSkipPersistence | Minor | proc-v2 |
+| [HBASE-21862](https://issues.apache.org/jira/browse/HBASE-21862) | IPCUtil.wrapException should keep the original exception types for all the connection exceptions | Blocker | . |
+| [HBASE-18484](https://issues.apache.org/jira/browse/HBASE-18484) | VerifyRep by snapshot does not work when Yarn / SourceHBase / PeerHBase located in different HDFS clusters | Major | Replication |
+| [HBASE-21775](https://issues.apache.org/jira/browse/HBASE-21775) | The BufferedMutator doesn't ever refresh region location cache | Major | Client |
+| [HBASE-21843](https://issues.apache.org/jira/browse/HBASE-21843) | RegionGroupingProvider breaks the meta wal file name pattern which may cause data loss for meta region | Blocker | wal |
+| [HBASE-21795](https://issues.apache.org/jira/browse/HBASE-21795) | Client application may get stuck (time bound) if a table modify op is called immediately after split op | Critical | amv2 |
+| [HBASE-21840](https://issues.apache.org/jira/browse/HBASE-21840) | TestHRegionWithInMemoryFlush fails with NPE | Blocker | test |
+| [HBASE-21811](https://issues.apache.org/jira/browse/HBASE-21811) | region can be opened on two servers due to race condition with procedures and server reports | Blocker | amv2 |
+| [HBASE-21644](https://issues.apache.org/jira/browse/HBASE-21644) | Modify table procedure runs infinitely for a table having region replication \> 1 | Critical | Admin |
+| [HBASE-21733](https://issues.apache.org/jira/browse/HBASE-21733) | SnapshotQuotaObserverChore should only fetch space quotas | Major | . |
+| [HBASE-21699](https://issues.apache.org/jira/browse/HBASE-21699) | Create table failed when using SPLITS\_FILE =\> 'splits.txt' | Blocker | Client, shell |
+| [HBASE-21535](https://issues.apache.org/jira/browse/HBASE-21535) | Zombie Master detector is not working | Critical | master |
+| [HBASE-21770](https://issues.apache.org/jira/browse/HBASE-21770) | Should deal with meta table in HRegionLocator.getAllRegionLocations | Major | Client |
+| [HBASE-21754](https://issues.apache.org/jira/browse/HBASE-21754) | ReportRegionStateTransitionRequest should be executed in priority executor | Major | . |
+| [HBASE-21475](https://issues.apache.org/jira/browse/HBASE-21475) | Put mutation (having TTL set) added via co-processor is retrieved even after TTL expires | Major | Coprocessors |
+| [HBASE-21749](https://issues.apache.org/jira/browse/HBASE-21749) | RS UI may throw NPE and make rs-status page inaccessible with multiwal and replication | Major | Replication, UI |
+| [HBASE-21746](https://issues.apache.org/jira/browse/HBASE-21746) | Fix two concern cases in RegionMover | Major | . |
+| [HBASE-21732](https://issues.apache.org/jira/browse/HBASE-21732) | Should call toUpperCase before using Enum.valueOf in some methods for ColumnFamilyDescriptor | Critical | Client |
+| [HBASE-21704](https://issues.apache.org/jira/browse/HBASE-21704) | The implementation of DistributedHBaseCluster.getServerHoldingRegion is incorrect | Major | . |
+| [HBASE-20917](https://issues.apache.org/jira/browse/HBASE-20917) | MetaTableMetrics#stop references uninitialized requestsMap for non-meta region | Major | meta, metrics |
+| [HBASE-21639](https://issues.apache.org/jira/browse/HBASE-21639) | maxHeapUsage value not read properly from config during EntryBuffers initialization | Minor | . |
+| [HBASE-21225](https://issues.apache.org/jira/browse/HBASE-21225) | Having RPC & Space quota on a table/Namespace doesn't allow space quota to be removed using 'NONE' | Major | . |
+| [HBASE-21707](https://issues.apache.org/jira/browse/HBASE-21707) | Fix warnings in hbase-rsgroup module and also make the UTs more stable | Major | Region Assignment, rsgroup |
+| [HBASE-20220](https://issues.apache.org/jira/browse/HBASE-20220) | [RSGroup] Check if table exists in the cluster before moving it to the specified regionserver group | Major | rsgroup |
+| [HBASE-21691](https://issues.apache.org/jira/browse/HBASE-21691) | Fix flaky test TestRecoveredEdits | Major | . |
+| [HBASE-21695](https://issues.apache.org/jira/browse/HBASE-21695) | Fix flaky test TestRegionServerAbortTimeout | Major | . |
+| [HBASE-21614](https://issues.apache.org/jira/browse/HBASE-21614) | RIT recovery with ServerCrashProcedure doesn't account for all regions | Critical | amv2 |
+| [HBASE-21618](https://issues.apache.org/jira/browse/HBASE-21618) | Scan with the same startRow(inclusive=true) and stopRow(inclusive=false) returns one result | Critical | Client |
+| [HBASE-21683](https://issues.apache.org/jira/browse/HBASE-21683) | Reset readsEnabled flag after successfully flushing the primary region | Critical | read replicas |
+| [HBASE-21630](https://issues.apache.org/jira/browse/HBASE-21630) | [shell] Define ENDKEY == STOPROW (we have ENDROW) | Trivial | shell |
+| [HBASE-21547](https://issues.apache.org/jira/browse/HBASE-21547) | Precommit uses master flaky list for other branches | Major | test |
+| [HBASE-21660](https://issues.apache.org/jira/browse/HBASE-21660) | Apply the cell to right memstore for increment/append operation | Major | . |
+| [HBASE-21646](https://issues.apache.org/jira/browse/HBASE-21646) | Flakey TestTableSnapshotInputFormat; DisableTable not completing... | Major | test |
+| [HBASE-21545](https://issues.apache.org/jira/browse/HBASE-21545) | NEW\_VERSION\_BEHAVIOR breaks Get/Scan with specified columns | Major | API |
+| [HBASE-21629](https://issues.apache.org/jira/browse/HBASE-21629) | draining\_servers.rb is broken | Major | scripts |
+| [HBASE-21621](https://issues.apache.org/jira/browse/HBASE-21621) | Reversed scan does not return expected number of rows | Critical | Scanners |
+| [HBASE-21620](https://issues.apache.org/jira/browse/HBASE-21620) | Problem in scan query when using more than one column prefix filter in some cases. | Major | Scanners |
+| [HBASE-21610](https://issues.apache.org/jira/browse/HBASE-21610) | numOpenConnections metric is set to -1 when zero server channel exist | Minor | metrics |
+| [HBASE-21498](https://issues.apache.org/jira/browse/HBASE-21498) | Master OOM when SplitTableRegionProcedure new CacheConfig and instantiate a new BlockCache | Major | . |
+| [HBASE-21592](https://issues.apache.org/jira/browse/HBASE-21592) | quota.addGetResult(r) throw NPE | Major | . |
+| [HBASE-21589](https://issues.apache.org/jira/browse/HBASE-21589) | TestCleanupMetaWAL fails | Blocker | test, wal |
+| [HBASE-21575](https://issues.apache.org/jira/browse/HBASE-21575) | memstore above high watermark message is logged too much | Minor | logging, regionserver |
+| [HBASE-21582](https://issues.apache.org/jira/browse/HBASE-21582) | If call HBaseAdmin#snapshotAsync but forget call isSnapshotFinished, then SnapshotHFileCleaner will skip to run every time | Major | . |
+| [HBASE-21568](https://issues.apache.org/jira/browse/HBASE-21568) | Disable use of BlockCache for LoadIncrementalHFiles | Major | Client |
+| [HBASE-21453](https://issues.apache.org/jira/browse/HBASE-21453) | Convert ReadOnlyZKClient to DEBUG instead of INFO | Major | logging, Zookeeper |
+| [HBASE-21559](https://issues.apache.org/jira/browse/HBASE-21559) | The RestoreSnapshotFromClientTestBase related UT are flaky | Major | . |
+| [HBASE-21551](https://issues.apache.org/jira/browse/HBASE-21551) | Memory leak when use scan with STREAM at server side | Blocker | regionserver |
+| [HBASE-21550](https://issues.apache.org/jira/browse/HBASE-21550) | Add a new method preCreateTableRegionInfos for MasterObserver which allows CPs to modify the TableDescriptor | Major | Coprocessors |
+| [HBASE-21479](https://issues.apache.org/jira/browse/HBASE-21479) | Individual tests in TestHRegionReplayEvents class are failing | Major | . |
+| [HBASE-21518](https://issues.apache.org/jira/browse/HBASE-21518) | TestMasterFailoverWithProcedures is flaky | Major | . |
+| [HBASE-21504](https://issues.apache.org/jira/browse/HBASE-21504) | If enable FIFOCompactionPolicy, a compaction may write a "empty" hfile whose maxTimeStamp is long max. This kind of hfile will never be archived. | Critical | Compaction |
+| [HBASE-21300](https://issues.apache.org/jira/browse/HBASE-21300) | Fix the wrong reference file path when restoring snapshots for tables with MOB columns | Major | . |
+| [HBASE-21507](https://issues.apache.org/jira/browse/HBASE-21507) | Compaction failed when execute AbstractMultiFileWriter.beforeShipped() method | Major | Compaction, regionserver |
+| [HBASE-21387](https://issues.apache.org/jira/browse/HBASE-21387) | Race condition surrounding in progress snapshot handling in snapshot cache leads to loss of snapshot files | Major | snapshots |
+| [HBASE-21503](https://issues.apache.org/jira/browse/HBASE-21503) | Replication normal source can get stuck due potential race conditions between source wal reader and wal provider initialization threads. | Blocker | Replication |
+| [HBASE-21466](https://issues.apache.org/jira/browse/HBASE-21466) | WALProcedureStore uses wrong FileSystem if wal.dir is not under rootdir | Major | . |
+| [HBASE-21445](https://issues.apache.org/jira/browse/HBASE-21445) | CopyTable by bulkload will write hfile into yarn's HDFS | Major | mapreduce |
+| [HBASE-21437](https://issues.apache.org/jira/browse/HBASE-21437) | Bypassed procedure throw IllegalArgumentException when its state is WAITING\_TIMEOUT | Major | . |
+| [HBASE-21439](https://issues.apache.org/jira/browse/HBASE-21439) | StochasticLoadBalancer RegionLoads aren’t being used in RegionLoad cost functions | Major | Balancer |
+| [HBASE-20604](https://issues.apache.org/jira/browse/HBASE-20604) | ProtobufLogReader#readNext can incorrectly loop to the same position in the stream until the the WAL is rolled | Critical | Replication, wal |
+| [HBASE-21247](https://issues.apache.org/jira/browse/HBASE-21247) | Custom Meta WAL Provider doesn't default to custom WAL Provider whose configuration value is outside the enums in Providers | Major | wal |
+| [HBASE-21430](https://issues.apache.org/jira/browse/HBASE-21430) | [hbase-connectors] Move hbase-spark\* modules to hbase-connectors repo | Major | hbase-connectors, spark |
+| [HBASE-21438](https://issues.apache.org/jira/browse/HBASE-21438) | TestAdmin2#testGetProcedures fails due to FailedProcedure inaccessible | Major | . |
+| [HBASE-21425](https://issues.apache.org/jira/browse/HBASE-21425) | 2.1.1 fails to start over 1.x data; namespace not assigned | Critical | amv2 |
+| [HBASE-21407](https://issues.apache.org/jira/browse/HBASE-21407) | Resolve NPE in backup Master UI | Minor | UI |
+| [HBASE-21422](https://issues.apache.org/jira/browse/HBASE-21422) | NPE in TestMergeTableRegionsProcedure.testMergeWithoutPONR | Major | proc-v2, test |
+| [HBASE-21424](https://issues.apache.org/jira/browse/HBASE-21424) | Change flakies and nightlies so scheduled less often | Major | build |
+| [HBASE-21417](https://issues.apache.org/jira/browse/HBASE-21417) | Pre commit build is broken due to surefire plugin crashes | Critical | build |
+| [HBASE-21371](https://issues.apache.org/jira/browse/HBASE-21371) | Hbase unable to compile against Hadoop trunk (3.3.0-SNAPSHOT) due to license error | Major | . |
+| [HBASE-21391](https://issues.apache.org/jira/browse/HBASE-21391) | RefreshPeerProcedure should also wait master initialized before executing | Major | Replication |
+| [HBASE-21342](https://issues.apache.org/jira/browse/HBASE-21342) | FileSystem in use may get closed by other bulk load call in secure bulkLoad | Major | . |
+| [HBASE-21349](https://issues.apache.org/jira/browse/HBASE-21349) | Cluster is going down but CatalogJanitor and Normalizer try to run and fail noisely | Minor | . |
+| [HBASE-21356](https://issues.apache.org/jira/browse/HBASE-21356) | bulkLoadHFile API should ensure that rs has the source hfile's write permission | Major | . |
+| [HBASE-21355](https://issues.apache.org/jira/browse/HBASE-21355) | HStore's storeSize is calculated repeatedly which causing the confusing region split | Blocker | regionserver |
+| [HBASE-21334](https://issues.apache.org/jira/browse/HBASE-21334) | TestMergeTableRegionsProcedure is flakey | Major | amv2, proc-v2, test |
+| [HBASE-21178](https://issues.apache.org/jira/browse/HBASE-21178) | [BC break] : Get and Scan operation with a custom converter\_class not working | Critical | shell |
+| [HBASE-21200](https://issues.apache.org/jira/browse/HBASE-21200) | Memstore flush doesn't finish because of seekToPreviousRow() in memstore scanner. | Critical | Scanners |
+| [HBASE-21292](https://issues.apache.org/jira/browse/HBASE-21292) | IdLock.getLockEntry() may hang if interrupted | Major | . |
+| [HBASE-21335](https://issues.apache.org/jira/browse/HBASE-21335) | Change the default wait time of HBCK2 tool | Critical | . |
+| [HBASE-21291](https://issues.apache.org/jira/browse/HBASE-21291) | Add a test for bypassing stuck state-machine procedures | Major | . |
+| [HBASE-21055](https://issues.apache.org/jira/browse/HBASE-21055) | NullPointerException when balanceOverall() but server balance info is null | Major | Balancer |
+| [HBASE-21327](https://issues.apache.org/jira/browse/HBASE-21327) | Fix minor logging issue where we don't report servername if no associated SCP | Trivial | amv2 |
+| [HBASE-21320](https://issues.apache.org/jira/browse/HBASE-21320) | [canary] Cleanup of usage and add commentary | Major | canary |
+| [HBASE-21266](https://issues.apache.org/jira/browse/HBASE-21266) | Not running balancer because processing dead regionservers, but empty dead rs list | Major | . |
+| [HBASE-21260](https://issues.apache.org/jira/browse/HBASE-21260) | The whole balancer plans might be aborted if there are more than one plans to move a same region | Major | Balancer, master |
+| [HBASE-21280](https://issues.apache.org/jira/browse/HBASE-21280) | Add anchors for each heading in UI | Trivial | UI, Usability |
+| [HBASE-20764](https://issues.apache.org/jira/browse/HBASE-20764) | build broken when latest commit is gpg signed | Critical | build |
+| [HBASE-18549](https://issues.apache.org/jira/browse/HBASE-18549) | Unclaimed replication queues can go undetected | Critical | Replication |
+| [HBASE-21248](https://issues.apache.org/jira/browse/HBASE-21248) | Implement exponential backoff when retrying for ModifyPeerProcedure | Major | proc-v2, Replication |
+| [HBASE-21196](https://issues.apache.org/jira/browse/HBASE-21196) | HTableMultiplexer clears the meta cache after every put operation | Critical | Performance |
+| [HBASE-19418](https://issues.apache.org/jira/browse/HBASE-19418) | RANGE\_OF\_DELAY in PeriodicMemstoreFlusher should be configurable. | Minor | . |
+| [HBASE-18451](https://issues.apache.org/jira/browse/HBASE-18451) | PeriodicMemstoreFlusher should inspect the queue before adding a delayed flush request | Major | regionserver |
+| [HBASE-21228](https://issues.apache.org/jira/browse/HBASE-21228) | Memory leak since AbstractFSWAL caches Thread object and never clean later | Critical | wal |
+| [HBASE-20766](https://issues.apache.org/jira/browse/HBASE-20766) | Verify Replication Tool Has Typo "remove cluster" | Trivial | . |
+| [HBASE-21232](https://issues.apache.org/jira/browse/HBASE-21232) | Show table state in Tables view on Master home page | Major | Operability, UI |
+| [HBASE-21212](https://issues.apache.org/jira/browse/HBASE-21212) | Wrong flush time when update flush metric | Minor | . |
+| [HBASE-21208](https://issues.apache.org/jira/browse/HBASE-21208) | Bytes#toShort doesn't work without unsafe | Critical | . |
+| [HBASE-20704](https://issues.apache.org/jira/browse/HBASE-20704) | Sometimes some compacted storefiles are not archived on region close | Critical | Compaction |
+| [HBASE-21203](https://issues.apache.org/jira/browse/HBASE-21203) | TestZKMainServer#testCommandLineWorks won't pass with default 4lw whitelist | Minor | test, Zookeeper |
+| [HBASE-21102](https://issues.apache.org/jira/browse/HBASE-21102) | ServerCrashProcedure should select target server where no other replicas exist for the current region | Major | Region Assignment |
+| [HBASE-21206](https://issues.apache.org/jira/browse/HBASE-21206) | Scan with batch size may return incomplete cells | Critical | Scanners |
+| [HBASE-21182](https://issues.apache.org/jira/browse/HBASE-21182) | Failed to execute start-hbase.sh | Major | . |
+| [HBASE-21179](https://issues.apache.org/jira/browse/HBASE-21179) | Fix the number of actions in responseTooSlow log | Major | logging, rpc |
+| [HBASE-21174](https://issues.apache.org/jira/browse/HBASE-21174) | [REST] Failed to parse empty qualifier in TableResource#getScanResource | Major | REST |
+| [HBASE-21181](https://issues.apache.org/jira/browse/HBASE-21181) | Use the same filesystem for wal archive directory and wal directory | Major | . |
+| [HBASE-21021](https://issues.apache.org/jira/browse/HBASE-21021) | Result returned by Append operation should be ordered | Major | . |
+| [HBASE-21173](https://issues.apache.org/jira/browse/HBASE-21173) | Remove the duplicate HRegion#close in TestHRegion | Minor | test |
+| [HBASE-21144](https://issues.apache.org/jira/browse/HBASE-21144) | AssignmentManager.waitForAssignment is not stable | Major | amv2, test |
+| [HBASE-21143](https://issues.apache.org/jira/browse/HBASE-21143) | Update findbugs-maven-plugin to 3.0.4 | Major | pom |
+| [HBASE-21171](https://issues.apache.org/jira/browse/HBASE-21171) | [amv2] Tool to parse a directory of MasterProcWALs standalone | Major | amv2, test |
+| [HBASE-21052](https://issues.apache.org/jira/browse/HBASE-21052) | After restoring a snapshot, table.jsp page for the table gets stuck | Major | snapshots |
+| [HBASE-21001](https://issues.apache.org/jira/browse/HBASE-21001) | ReplicationObserver fails to load in HBase 2.0.0 | Major | . |
+| [HBASE-20741](https://issues.apache.org/jira/browse/HBASE-20741) | Split of a region with replicas creates all daughter regions and its replica in same server | Major | read replicas |
+| [HBASE-21127](https://issues.apache.org/jira/browse/HBASE-21127) | TableRecordReader need to handle cursor result too | Major | . |
+| [HBASE-20892](https://issues.apache.org/jira/browse/HBASE-20892) | [UI] Start / End keys are empty on table.jsp | Major | . |
+| [HBASE-21136](https://issues.apache.org/jira/browse/HBASE-21136) | NPE in MetricsTableSourceImpl.updateFlushTime | Major | metrics |
+| [HBASE-21132](https://issues.apache.org/jira/browse/HBASE-21132) | return wrong result in rest multiget | Major | . |
+| [HBASE-21128](https://issues.apache.org/jira/browse/HBASE-21128) | TestAsyncRegionAdminApi.testAssignRegionAndUnassignRegion is broken | Major | test |
+| [HBASE-20940](https://issues.apache.org/jira/browse/HBASE-20940) | HStore.cansplit should not allow split to happen if it has references | Major | . |
+| [HBASE-21084](https://issues.apache.org/jira/browse/HBASE-21084) | When cloning a snapshot including a split parent region, the split parent region of the cloned table will be online | Major | snapshots |
+| [HBASE-20968](https://issues.apache.org/jira/browse/HBASE-20968) | list\_procedures\_test fails due to no matching regex | Major | shell, test |
+| [HBASE-21030](https://issues.apache.org/jira/browse/HBASE-21030) | Correct javadoc for append operation | Minor | documentation |
+| [HBASE-21088](https://issues.apache.org/jira/browse/HBASE-21088) | HStoreFile should be closed in HStore#hasReferences | Major | . |
+| [HBASE-20890](https://issues.apache.org/jira/browse/HBASE-20890) | PE filterScan seems to be stuck forever | Minor | . |
+| [HBASE-20772](https://issues.apache.org/jira/browse/HBASE-20772) | Controlled shutdown fills Master log with the disturbing message "No matching procedure found for rit=OPEN, location=ZZZZ, table=YYYYY, region=XXXX transition to CLOSED | Major | logging |
+| [HBASE-20978](https://issues.apache.org/jira/browse/HBASE-20978) | [amv2] Worker terminating UNNATURALLY during MoveRegionProcedure | Critical | amv2 |
+| [HBASE-21078](https://issues.apache.org/jira/browse/HBASE-21078) | [amv2] CODE-BUG NPE in RTP doing Unassign | Major | amv2 |
+| [HBASE-21113](https://issues.apache.org/jira/browse/HBASE-21113) | Apply the branch-2 version of HBASE-21095, The timeout retry logic for several procedures are broken after master restarts | Major | amv2 |
+| [HBASE-21101](https://issues.apache.org/jira/browse/HBASE-21101) | Remove the waitUntilAllRegionsAssigned call after split in TestTruncateTableProcedure | Major | test |
+| [HBASE-19008](https://issues.apache.org/jira/browse/HBASE-19008) | Add missing equals or hashCode method(s) to stock Filter implementations | Major | . |
+| [HBASE-20614](https://issues.apache.org/jira/browse/HBASE-20614) | REST scan API with incorrect filter text file throws HTTP 503 Service Unavailable error | Minor | REST |
+| [HBASE-21041](https://issues.apache.org/jira/browse/HBASE-21041) | Memstore's heap size will be decreased to minus zero after flush | Major | . |
+| [HBASE-21031](https://issues.apache.org/jira/browse/HBASE-21031) | Memory leak if replay edits failed during region opening | Major | . |
+| [HBASE-20666](https://issues.apache.org/jira/browse/HBASE-20666) | Unsuccessful table creation leaves entry in hbase:rsgroup table | Minor | . |
+| [HBASE-21032](https://issues.apache.org/jira/browse/HBASE-21032) | ScanResponses contain only one cell each | Major | Performance, Scanners |
+| [HBASE-20705](https://issues.apache.org/jira/browse/HBASE-20705) | Having RPC Quota on a table prevents Space quota to be recreated/removed | Major | . |
+| [HBASE-21058](https://issues.apache.org/jira/browse/HBASE-21058) | Nightly tests for branches 1 fail to build ref guide | Major | documentation |
+| [HBASE-21074](https://issues.apache.org/jira/browse/HBASE-21074) | JDK7 branches need to pass "-Dhttps.protocols=TLSv1.2" to maven when building | Major | build, community, test |
+| [HBASE-21062](https://issues.apache.org/jira/browse/HBASE-21062) | WALFactory has misleading notion of "default" | Major | wal |
+| [HBASE-21047](https://issues.apache.org/jira/browse/HBASE-21047) | Object creation of StoreFileScanner thru constructor and close may leave refCount to -1 | Major | . |
+| [HBASE-21005](https://issues.apache.org/jira/browse/HBASE-21005) | Maven site configuration causes downstream projects to get a directory named ${project.basedir} | Minor | build |
+| [HBASE-21007](https://issues.apache.org/jira/browse/HBASE-21007) | Memory leak in HBase rest server | Critical | REST |
+| [HBASE-20794](https://issues.apache.org/jira/browse/HBASE-20794) | CreateTable operation does not log its landing at the master nor the initiator at INFO level | Major | logging |
+| [HBASE-20538](https://issues.apache.org/jira/browse/HBASE-20538) | Upgrade our hadoop versions to 2.7.7 and 3.0.3 | Critical | java, security |
+| [HBASE-20927](https://issues.apache.org/jira/browse/HBASE-20927) | RSGroupAdminEndpoint doesn't handle clearing dead servers if they are not processed yet. | Major | . |
+| [HBASE-20932](https://issues.apache.org/jira/browse/HBASE-20932) | Effective MemStoreSize::hashCode() | Major | . |
+| [HBASE-20928](https://issues.apache.org/jira/browse/HBASE-20928) | Rewrite calculation of midpoint in binarySearch functions to prevent overflow | Minor | io |
+| [HBASE-20565](https://issues.apache.org/jira/browse/HBASE-20565) | ColumnRangeFilter combined with ColumnPaginationFilter can produce incorrect result since 1.4 | Major | Filters |
+| [HBASE-20908](https://issues.apache.org/jira/browse/HBASE-20908) | Infinite loop on regionserver if region replica are reduced | Major | read replicas |
+| [HBASE-19893](https://issues.apache.org/jira/browse/HBASE-19893) | restore\_snapshot is broken in master branch when region splits | Critical | snapshots |
+| [HBASE-20870](https://issues.apache.org/jira/browse/HBASE-20870) | Wrong HBase root dir in ITBLL's Search Tool | Minor | integration tests |
+| [HBASE-20901](https://issues.apache.org/jira/browse/HBASE-20901) | Reducing region replica has no effect | Major | . |
+| [HBASE-6028](https://issues.apache.org/jira/browse/HBASE-6028) | Implement a cancel for in-progress compactions | Minor | regionserver |
+| [HBASE-20869](https://issues.apache.org/jira/browse/HBASE-20869) | Endpoint-based Export use incorrect user to write to destination | Major | Coprocessors |
+| [HBASE-20879](https://issues.apache.org/jira/browse/HBASE-20879) | Compacting memstore config should handle lower case | Major | . |
+| [HBASE-20865](https://issues.apache.org/jira/browse/HBASE-20865) | CreateTableProcedure is stuck in retry loop in CREATE\_TABLE\_WRITE\_FS\_LAYOUT state | Major | amv2 |
+| [HBASE-19572](https://issues.apache.org/jira/browse/HBASE-19572) | RegionMover should use the configured default port number and not the one from HConstants | Major | . |
+| [HBASE-20697](https://issues.apache.org/jira/browse/HBASE-20697) | Can't cache All region locations of the specify table by calling table.getRegionLocator().getAllRegionLocations() | Major | meta |
+| [HBASE-20791](https://issues.apache.org/jira/browse/HBASE-20791) | RSGroupBasedLoadBalancer#setClusterMetrics should pass ClusterMetrics to its internalBalancer | Major | Balancer, rsgroup |
+| [HBASE-20770](https://issues.apache.org/jira/browse/HBASE-20770) | WAL cleaner logs way too much; gets clogged when lots of work to do | Critical | logging |
+
+
+### TESTS:
+
+| JIRA | Summary | Priority | Component |
+|:---- |:---- | :--- |:---- |
+| [HBASE-21963](https://issues.apache.org/jira/browse/HBASE-21963) | Add a script for building and verifying release candidate | Minor | community, scripts |
+| [HBASE-21756](https://issues.apache.org/jira/browse/HBASE-21756) | Backport HBASE-21279 (Split TestAdminShell into several tests) to branch-2 | Major | . |
+| [HBASE-20136](https://issues.apache.org/jira/browse/HBASE-20136) | TestKeyValue misses ClassRule and Category annotations | Minor | . |
+| [HBASE-21261](https://issues.apache.org/jira/browse/HBASE-21261) | Add log4j.properties for hbase-rsgroup tests | Trivial | . |
+| [HBASE-21258](https://issues.apache.org/jira/browse/HBASE-21258) | Add resetting of flags for RS Group pre/post hooks in TestRSGroups | Major | . |
+| [HBASE-21097](https://issues.apache.org/jira/browse/HBASE-21097) | Flush pressure assertion may fail in testFlushThroughputTuning | Major | regionserver |
+| [HBASE-21138](https://issues.apache.org/jira/browse/HBASE-21138) | Close HRegion instance at the end of every test in TestHRegion | Major | . |
+| [HBASE-21161](https://issues.apache.org/jira/browse/HBASE-21161) | Enable the test added in HBASE-20741 that was removed accidentally | Minor | . |
+| [HBASE-21076](https://issues.apache.org/jira/browse/HBASE-21076) | TestTableResource fails with NPE | Major | REST, test |
+| [HBASE-20907](https://issues.apache.org/jira/browse/HBASE-20907) | Fix Intermittent failure on TestProcedurePriority | Major | . |
+| [HBASE-20838](https://issues.apache.org/jira/browse/HBASE-20838) | Include hbase-server in precommit test if CommonFSUtils is changed | Major | . |
+
+
+### SUB-TASKS:
+
+| JIRA | Summary | Priority | Component |
+|:---- |:---- | :--- |:---- |
+| [HBASE-22430](https://issues.apache.org/jira/browse/HBASE-22430) | hbase-vote should tee build and test output to console | Trivial | . |
+| [HBASE-22429](https://issues.apache.org/jira/browse/HBASE-22429) | hbase-vote download step requires URL to end with '/' | Trivial | . |
+| [HBASE-22405](https://issues.apache.org/jira/browse/HBASE-22405) | Update Ref Guide for EOL of Hadoop 2.7 | Major | community, documentation |
+| [HBASE-22325](https://issues.apache.org/jira/browse/HBASE-22325) | AsyncRpcRetryingCaller will not schedule retry if we hit a NotServingRegionException but there is no TableName provided | Major | asyncclient, Client |
+| [HBASE-22322](https://issues.apache.org/jira/browse/HBASE-22322) | Use special pause for CallQueueTooBigException | Major | asyncclient, Client |
+| [HBASE-22317](https://issues.apache.org/jira/browse/HBASE-22317) | Support reading from meta replicas | Major | asyncclient, read replicas |
+| [HBASE-22261](https://issues.apache.org/jira/browse/HBASE-22261) | Make use of ClusterStatusListener for async client | Major | asyncclient |
+| [HBASE-22267](https://issues.apache.org/jira/browse/HBASE-22267) | Implement client push back for async client | Major | asyncclient |
+| [HBASE-19763](https://issues.apache.org/jira/browse/HBASE-19763) | Fix Checkstyle errors in hbase-procedure | Minor | . |
+| [HBASE-22244](https://issues.apache.org/jira/browse/HBASE-22244) | Make use of MetricsConnection in async client | Major | asyncclient, metrics |
+| [HBASE-22196](https://issues.apache.org/jira/browse/HBASE-22196) | Split TestRestartCluster | Major | test |
+| [HBASE-22117](https://issues.apache.org/jira/browse/HBASE-22117) | Move hasPermission/checkPermissions from region server to master | Major | . |
+| [HBASE-21886](https://issues.apache.org/jira/browse/HBASE-21886) | Run ITBLL for branch-2.2 | Major | . |
+| [HBASE-22155](https://issues.apache.org/jira/browse/HBASE-22155) | Move 2.2.0 on to hbase-thirdparty-2.2.0 | Major | thirdparty |
+| [HBASE-22153](https://issues.apache.org/jira/browse/HBASE-22153) | Fix the flaky TestRestartCluster | Major | test |
+| [HBASE-22152](https://issues.apache.org/jira/browse/HBASE-22152) | Create a jenkins file for yetus to processing GitHub PR | Major | build |
+| [HBASE-22158](https://issues.apache.org/jira/browse/HBASE-22158) | RawAsyncHBaseAdmin.getTableSplits should filter out none default replicas | Major | Admin |
+| [HBASE-22157](https://issues.apache.org/jira/browse/HBASE-22157) | Include the cause when constructing RestoreSnapshotException in restoreSnapshot | Major | Admin |
+| [HBASE-22141](https://issues.apache.org/jira/browse/HBASE-22141) | Fix TestAsyncDecommissionAdminApi | Major | test |
+| [HBASE-22135](https://issues.apache.org/jira/browse/HBASE-22135) | AsyncAdmin will not refresh master address | Major | Admin, asyncclient, Client |
+| [HBASE-22101](https://issues.apache.org/jira/browse/HBASE-22101) | AsyncAdmin.isTableAvailable should not throw TableNotFoundException | Major | Admin, asyncclient, Client |
+| [HBASE-22094](https://issues.apache.org/jira/browse/HBASE-22094) | Throw TableNotFoundException if table not exists in AsyncAdmin.compact | Major | Admin |
+| [HBASE-21911](https://issues.apache.org/jira/browse/HBASE-21911) | Move getUserPermissions from regionserver to master | Major | . |
+| [HBASE-22015](https://issues.apache.org/jira/browse/HBASE-22015) | UserPermission should be annotated as InterfaceAudience.Public | Blocker | . |
+| [HBASE-22066](https://issues.apache.org/jira/browse/HBASE-22066) | Add markers to CHANGES.md and RELEASENOTES.md | Major | . |
+| [HBASE-22040](https://issues.apache.org/jira/browse/HBASE-22040) | Add mergeRegionsAsync with a List of region names method in AsyncAdmin | Major | Admin, asyncclient, Client |
+| [HBASE-22039](https://issues.apache.org/jira/browse/HBASE-22039) | Should add the synchronous parameter for the XXXSwitch method in AsyncAdmin | Major | Admin, asyncclient, Client |
+| [HBASE-22022](https://issues.apache.org/jira/browse/HBASE-22022) | nightly fails rat check down in the dev-support/hbase\_nightly\_source-artifact.sh check | Major | . |
+| [HBASE-22025](https://issues.apache.org/jira/browse/HBASE-22025) | RAT check fails in nightlies; fails on (old) test data files. | Major | . |
+| [HBASE-21977](https://issues.apache.org/jira/browse/HBASE-21977) | Skip replay WAL and update seqid when open regions restored from snapshot | Major | Region Assignment, snapshots |
+| [HBASE-21999](https://issues.apache.org/jira/browse/HBASE-21999) | [DEBUG] Exit if git returns empty revision! | Major | build |
+| [HBASE-22000](https://issues.apache.org/jira/browse/HBASE-22000) | Deprecated isTableAvailable with splitKeys | Major | asyncclient, Client |
+| [HBASE-21949](https://issues.apache.org/jira/browse/HBASE-21949) | Fix flaky test TestHBaseTestingUtility.testMiniZooKeeperWithMultipleClientPorts | Major | . |
+| [HBASE-21993](https://issues.apache.org/jira/browse/HBASE-21993) | Set version as 2.2.0 in branch-2.2 in prep for first RC | Major | . |
+| [HBASE-21997](https://issues.apache.org/jira/browse/HBASE-21997) | Fix hbase-rest findbugs ST\_WRITE\_TO\_STATIC\_FROM\_INSTANCE\_METHOD complaint | Major | REST |
+| [HBASE-21986](https://issues.apache.org/jira/browse/HBASE-21986) | Generate CHANGES.md and RELEASENOTES.md for 2.2.0 | Major | . |
+| [HBASE-21972](https://issues.apache.org/jira/browse/HBASE-21972) | Copy master doc into branch-2.2 and edit to make it suit 2.2.0 | Major | . |
+| [HBASE-15728](https://issues.apache.org/jira/browse/HBASE-15728) | Add remaining per-table region / store / flush / compaction related metrics | Major | metrics |
+| [HBASE-21934](https://issues.apache.org/jira/browse/HBASE-21934) | RemoteProcedureDispatcher should track the ongoing dispatched calls | Blocker | proc-v2 |
+| [HBASE-21588](https://issues.apache.org/jira/browse/HBASE-21588) | Procedure v2 wal splitting implementation | Major | . |
+| [HBASE-21729](https://issues.apache.org/jira/browse/HBASE-21729) | Extract ProcedureCoordinatorRpcs and ProcedureMemberRpcs from CoordinatedStateManager | Major | . |
+| [HBASE-21094](https://issues.apache.org/jira/browse/HBASE-21094) | Remove the explicit timeout config for TestTruncateTableProcedure | Major | test |
+| [HBASE-21093](https://issues.apache.org/jira/browse/HBASE-21093) | Move TestCreateTableProcedure.testMRegions to a separated file | Major | test |
+| [HBASE-18201](https://issues.apache.org/jira/browse/HBASE-18201) | add UT and docs for DataBlockEncodingTool | Minor | tooling |
+| [HBASE-21978](https://issues.apache.org/jira/browse/HBASE-21978) | Should close AsyncRegistry if we fail to get cluster id when creating AsyncConnection | Major | asyncclient, Client |
+| [HBASE-21974](https://issues.apache.org/jira/browse/HBASE-21974) | Change Admin#grant/revoke parameter from UserPermission to user and Permission | Major | . |
+| [HBASE-21970](https://issues.apache.org/jira/browse/HBASE-21970) | Document that how to upgrade from 2.0 or 2.1 to 2.2+ | Major | . |
+| [HBASE-21976](https://issues.apache.org/jira/browse/HBASE-21976) | Deal with RetryImmediatelyException for batching request | Major | asyncclient, Client |
+| [HBASE-21820](https://issues.apache.org/jira/browse/HBASE-21820) | Implement CLUSTER quota scope | Major | . |
+| [HBASE-21962](https://issues.apache.org/jira/browse/HBASE-21962) | Filters do not work in ThriftTable | Major | Thrift |
+| [HBASE-21927](https://issues.apache.org/jira/browse/HBASE-21927) | Always fail the locate request when error occur | Major | asyncclient, Client |
+| [HBASE-21944](https://issues.apache.org/jira/browse/HBASE-21944) | Validate put for batch operation | Major | asyncclient, Client |
+| [HBASE-21945](https://issues.apache.org/jira/browse/HBASE-21945) | Maintain the original order when sending batch request | Major | asyncclient, Client |
+| [HBASE-21783](https://issues.apache.org/jira/browse/HBASE-21783) | Support exceed user/table/ns throttle quota if region server has available quota | Major | . |
+| [HBASE-21930](https://issues.apache.org/jira/browse/HBASE-21930) | Deal with ScannerResetException when opening region scanner | Major | asyncclient, Client |
+| [HBASE-21907](https://issues.apache.org/jira/browse/HBASE-21907) | Should set priority for rpc request | Major | asyncclient, Client |
+| [HBASE-21909](https://issues.apache.org/jira/browse/HBASE-21909) | Validate the put instance before executing in AsyncTable.put method | Major | asyncclient, Client |
+| [HBASE-21814](https://issues.apache.org/jira/browse/HBASE-21814) | Remove the TODO in AccessControlLists#addUserPermission | Major | . |
+| [HBASE-19889](https://issues.apache.org/jira/browse/HBASE-19889) | Revert Workaround: Purge User API building from branch-2 so can make a beta-1 | Major | website |
+| [HBASE-21838](https://issues.apache.org/jira/browse/HBASE-21838) | Create a special ReplicationEndpoint just for verifying the WAL entries are fine | Major | Replication, wal |
+| [HBASE-21829](https://issues.apache.org/jira/browse/HBASE-21829) | Use FutureUtils.addListener instead of calling whenComplete directly | Major | asyncclient, Client |
+| [HBASE-21828](https://issues.apache.org/jira/browse/HBASE-21828) | Make sure we do not return CompletionException when locating region | Major | asyncclient, Client |
+| [HBASE-21764](https://issues.apache.org/jira/browse/HBASE-21764) | Size of in-memory compaction thread pool should be configurable | Major | Compaction, in-memory-compaction |
+| [HBASE-21809](https://issues.apache.org/jira/browse/HBASE-21809) | Add retry thrift client for ThriftTable/Admin | Major | . |
+| [HBASE-21739](https://issues.apache.org/jira/browse/HBASE-21739) | Move grant/revoke from regionserver to master | Major | . |
+| [HBASE-21798](https://issues.apache.org/jira/browse/HBASE-21798) | Cut branch-2.2 | Major | . |
+| [HBASE-20542](https://issues.apache.org/jira/browse/HBASE-20542) | Better heap utilization for IMC with MSLABs | Major | in-memory-compaction |
+| [HBASE-21713](https://issues.apache.org/jira/browse/HBASE-21713) | Support set region server throttle quota | Major | . |
+| [HBASE-21761](https://issues.apache.org/jira/browse/HBASE-21761) | Align the methods in RegionLocator and AsyncTableRegionLocator | Major | asyncclient, Client |
+| [HBASE-17370](https://issues.apache.org/jira/browse/HBASE-17370) | Fix or provide shell scripts to drain and decommission region server | Major | . |
+| [HBASE-21750](https://issues.apache.org/jira/browse/HBASE-21750) | Most of KeyValueUtil#length can be replaced by cell#getSerializedSize for better performance because the latter one has been optimized | Major | . |
+| [HBASE-21734](https://issues.apache.org/jira/browse/HBASE-21734) | Some optimization in FilterListWithOR | Major | . |
+| [HBASE-21738](https://issues.apache.org/jira/browse/HBASE-21738) | Remove all the CSLM#size operation in our memstore because it's an quite time consuming. | Critical | Performance |
+| [HBASE-21034](https://issues.apache.org/jira/browse/HBASE-21034) | Add new throttle type: read/write capacity unit | Major | . |
+| [HBASE-21726](https://issues.apache.org/jira/browse/HBASE-21726) | Add getAllRegionLocations method to AsyncTableRegionLocator | Major | asyncclient, Client |
+| [HBASE-19695](https://issues.apache.org/jira/browse/HBASE-19695) | Handle disabled table for async client | Major | asyncclient, Client |
+| [HBASE-21711](https://issues.apache.org/jira/browse/HBASE-21711) | Remove references to git.apache.org/hbase.git | Critical | . |
+| [HBASE-21647](https://issues.apache.org/jira/browse/HBASE-21647) | Add status track for splitting WAL tasks | Major | Operability |
+| [HBASE-21705](https://issues.apache.org/jira/browse/HBASE-21705) | Should treat meta table specially for some methods in AsyncAdmin | Major | Admin, asyncclient, Client |
+| [HBASE-21663](https://issues.apache.org/jira/browse/HBASE-21663) | Add replica scan support | Major | asyncclient, Client, read replicas |
+| [HBASE-21580](https://issues.apache.org/jira/browse/HBASE-21580) | Support getting Hbck instance from AsyncConnection | Major | asyncclient, Client, hbck2 |
+| [HBASE-21652](https://issues.apache.org/jira/browse/HBASE-21652) | Refactor ThriftServer making thrift2 server inherited from thrift1 server | Major | . |
+| [HBASE-21661](https://issues.apache.org/jira/browse/HBASE-21661) | Provide Thrift2 implementation of Table/Admin | Major | . |
+| [HBASE-21682](https://issues.apache.org/jira/browse/HBASE-21682) | Support getting from specific replica | Major | read replicas |
+| [HBASE-21159](https://issues.apache.org/jira/browse/HBASE-21159) | Add shell command to switch throttle on or off | Major | . |
+| [HBASE-21362](https://issues.apache.org/jira/browse/HBASE-21362) | Disable printing of stack-trace in shell when quotas are violated | Minor | shell |
+| [HBASE-21361](https://issues.apache.org/jira/browse/HBASE-21361) | Disable printing of stack-trace in shell when quotas are not enabled | Minor | shell |
+| [HBASE-17356](https://issues.apache.org/jira/browse/HBASE-17356) | Add replica get support | Major | Client |
+| [HBASE-21650](https://issues.apache.org/jira/browse/HBASE-21650) | Add DDL operation and some other miscellaneous to thrift2 | Major | Thrift |
+| [HBASE-21401](https://issues.apache.org/jira/browse/HBASE-21401) | Sanity check when constructing the KeyValue | Critical | regionserver |
+| [HBASE-21578](https://issues.apache.org/jira/browse/HBASE-21578) | Fix wrong throttling exception for capacity unit | Major | . |
+| [HBASE-21570](https://issues.apache.org/jira/browse/HBASE-21570) | Add write buffer periodic flush support for AsyncBufferedMutator | Major | asyncclient, Client |
+| [HBASE-21465](https://issues.apache.org/jira/browse/HBASE-21465) | Retry on reportRegionStateTransition can lead to unexpected errors | Major | amv2 |
+| [HBASE-21508](https://issues.apache.org/jira/browse/HBASE-21508) | Ignore the reportRegionStateTransition call from a dead server | Major | amv2 |
+| [HBASE-21490](https://issues.apache.org/jira/browse/HBASE-21490) | WALProcedure may remove proc wal files still with active procedures | Major | proc-v2 |
+| [HBASE-21377](https://issues.apache.org/jira/browse/HBASE-21377) | Add debug log for procedure stack id related operations | Major | proc-v2 |
+| [HBASE-21472](https://issues.apache.org/jira/browse/HBASE-21472) | Should not persist the dispatched field for RegionRemoteProcedureBase | Major | amv2 |
+| [HBASE-21473](https://issues.apache.org/jira/browse/HBASE-21473) | RowIndexSeekerV1 may return cell with extra two \\x00\\x00 bytes which has no tags | Major | . |
+| [HBASE-21463](https://issues.apache.org/jira/browse/HBASE-21463) | The checkOnlineRegionsReport can accidentally complete a TRSP | Critical | amv2 |
+| [HBASE-21376](https://issues.apache.org/jira/browse/HBASE-21376) | Add some verbose log to MasterProcedureScheduler | Major | logging, proc-v2 |
+| [HBASE-21443](https://issues.apache.org/jira/browse/HBASE-21443) | [hbase-connectors] Purge hbase-\* modules from core now they've been moved to hbase-connectors | Major | hbase-connectors, spark |
+| [HBASE-21421](https://issues.apache.org/jira/browse/HBASE-21421) | Do not kill RS if reportOnlineRegions fails | Major | . |
+| [HBASE-21314](https://issues.apache.org/jira/browse/HBASE-21314) | The implementation of BitSetNode is not efficient | Major | proc-v2 |
+| [HBASE-21351](https://issues.apache.org/jira/browse/HBASE-21351) | The force update thread may have race with PE worker when the procedure is rolling back | Critical | proc-v2 |
+| [HBASE-21191](https://issues.apache.org/jira/browse/HBASE-21191) | Add a holding-pattern if no assign for meta or namespace (Can happen if masterprocwals have been cleared). | Major | amv2 |
+| [HBASE-21322](https://issues.apache.org/jira/browse/HBASE-21322) | Add a scheduleServerCrashProcedure() API to HbckService | Critical | hbck2 |
+| [HBASE-21375](https://issues.apache.org/jira/browse/HBASE-21375) | Revisit the lock and queue implementation in MasterProcedureScheduler | Major | proc-v2 |
+| [HBASE-20973](https://issues.apache.org/jira/browse/HBASE-20973) | ArrayIndexOutOfBoundsException when rolling back procedure | Critical | amv2 |
+| [HBASE-21384](https://issues.apache.org/jira/browse/HBASE-21384) | Procedure with holdlock=false should not be restored lock when restarts | Blocker | . |
+| [HBASE-21364](https://issues.apache.org/jira/browse/HBASE-21364) | Procedure holds the lock should put to front of the queue after restart | Blocker | . |
+| [HBASE-21215](https://issues.apache.org/jira/browse/HBASE-21215) | Figure how to invoke hbck2; make it easy to find | Major | amv2, hbck2 |
+| [HBASE-21372](https://issues.apache.org/jira/browse/HBASE-21372) | Set hbase.assignment.maximum.attempts to Long.MAX | Major | amv2 |
+| [HBASE-21363](https://issues.apache.org/jira/browse/HBASE-21363) | Rewrite the buildingHoldCleanupTracker method in WALProcedureStore | Major | proc-v2 |
+| [HBASE-21338](https://issues.apache.org/jira/browse/HBASE-21338) | [balancer] If balancer is an ill-fit for cluster size, it gives little indication | Major | Balancer, Operability |
+| [HBASE-21192](https://issues.apache.org/jira/browse/HBASE-21192) | Add HOW-TO repair damaged AMv2. | Major | amv2 |
+| [HBASE-21073](https://issues.apache.org/jira/browse/HBASE-21073) | "Maintenance mode" master | Major | amv2, hbck2, master |
+| [HBASE-21354](https://issues.apache.org/jira/browse/HBASE-21354) | Procedure may be deleted improperly during master restarts resulting in 'Corrupt' | Major | . |
+| [HBASE-21336](https://issues.apache.org/jira/browse/HBASE-21336) | Simplify the implementation of WALProcedureMap | Major | proc-v2 |
+| [HBASE-21323](https://issues.apache.org/jira/browse/HBASE-21323) | Should not skip force updating for a sub procedure even if it has been finished | Major | proc-v2 |
+| [HBASE-21269](https://issues.apache.org/jira/browse/HBASE-21269) | Forward-port to branch-2 " HBASE-21213 [hbck2] bypass leaves behind state in RegionStates when assign/unassign" | Major | amv2 |
+| [HBASE-20716](https://issues.apache.org/jira/browse/HBASE-20716) | Unsafe access cleanup | Critical | Performance |
+| [HBASE-21330](https://issues.apache.org/jira/browse/HBASE-21330) | ReopenTableRegionsProcedure will enter an infinite loop if we schedule a TRSP at the same time | Major | amv2 |
+| [HBASE-21310](https://issues.apache.org/jira/browse/HBASE-21310) | Split TestCloneSnapshotFromClient | Major | test |
+| [HBASE-21311](https://issues.apache.org/jira/browse/HBASE-21311) | Split TestRestoreSnapshotFromClient | Major | test |
+| [HBASE-21315](https://issues.apache.org/jira/browse/HBASE-21315) | The getActiveMinProcId and getActiveMaxProcId of BitSetNode are incorrect if there are no active procedure | Major | . |
+| [HBASE-21278](https://issues.apache.org/jira/browse/HBASE-21278) | Do not rollback successful sub procedures when rolling back a procedure | Critical | proc-v2 |
+| [HBASE-21309](https://issues.apache.org/jira/browse/HBASE-21309) | Increase the waiting timeout for TestProcedurePriority | Major | test |
+| [HBASE-21254](https://issues.apache.org/jira/browse/HBASE-21254) | Need to find a way to limit the number of proc wal files | Critical | proc-v2 |
+| [HBASE-21250](https://issues.apache.org/jira/browse/HBASE-21250) | Refactor WALProcedureStore and add more comments for better understanding the implementation | Major | proc-v2 |
+| [HBASE-19275](https://issues.apache.org/jira/browse/HBASE-19275) | TestSnapshotFileCache never worked properly | Major | . |
+| [HBASE-21249](https://issues.apache.org/jira/browse/HBASE-21249) | Add jitter for ProcedureUtil.getBackoffTimeMs | Major | proc-v2 |
+| [HBASE-21244](https://issues.apache.org/jira/browse/HBASE-21244) | Skip persistence when retrying for assignment related procedures | Major | amv2, Performance, proc-v2 |
+| [HBASE-21233](https://issues.apache.org/jira/browse/HBASE-21233) | Allow the procedure implementation to skip persistence of the state after a execution | Major | Performance, proc-v2 |
+| [HBASE-21227](https://issues.apache.org/jira/browse/HBASE-21227) | Implement exponential retrying backoff for Assign/UnassignRegionHandler introduced in HBASE-21217 | Major | amv2, regionserver |
+| [HBASE-21217](https://issues.apache.org/jira/browse/HBASE-21217) | Revisit the executeProcedure method for open/close region | Critical | amv2, proc-v2 |
+| [HBASE-21214](https://issues.apache.org/jira/browse/HBASE-21214) | [hbck2] setTableState just sets hbase:meta state, not in-memory state | Major | amv2, hbck2 |
+| [HBASE-21023](https://issues.apache.org/jira/browse/HBASE-21023) | Add bypassProcedureToCompletion() API to HbckService | Major | hbck2 |
+| [HBASE-21156](https://issues.apache.org/jira/browse/HBASE-21156) | [hbck2] Queue an assign of hbase:meta and bulk assign/unassign | Critical | hbck2 |
+| [HBASE-21169](https://issues.apache.org/jira/browse/HBASE-21169) | Initiate hbck2 tool in hbase-operator-tools repo | Major | hbck2 |
+| [HBASE-21172](https://issues.apache.org/jira/browse/HBASE-21172) | Reimplement the retry backoff logic for ReopenTableRegionsProcedure | Major | amv2, proc-v2 |
+| [HBASE-21189](https://issues.apache.org/jira/browse/HBASE-21189) | flaky job should gather machine stats | Minor | test |
+| [HBASE-21190](https://issues.apache.org/jira/browse/HBASE-21190) | Log files and count of entries in each as we load from the MasterProcWAL store | Major | amv2 |
+| [HBASE-21083](https://issues.apache.org/jira/browse/HBASE-21083) | Introduce a mechanism to bypass the execution of a stuck procedure | Major | amv2 |
+| [HBASE-21017](https://issues.apache.org/jira/browse/HBASE-21017) | Revisit the expected states for open/close | Major | amv2 |
+| [HBASE-20941](https://issues.apache.org/jira/browse/HBASE-20941) | Create and implement HbckService in master | Major | . |
+| [HBASE-21072](https://issues.apache.org/jira/browse/HBASE-21072) | Block out HBCK1 in hbase2 | Major | hbck |
+| [HBASE-21095](https://issues.apache.org/jira/browse/HBASE-21095) | The timeout retry logic for several procedures are broken after master restarts | Critical | amv2, proc-v2 |
+| [HBASE-20975](https://issues.apache.org/jira/browse/HBASE-20975) | Lock may not be taken or released while rolling back procedure | Major | amv2 |
+| [HBASE-21025](https://issues.apache.org/jira/browse/HBASE-21025) | Add cache for TableStateManager | Major | . |
+| [HBASE-21012](https://issues.apache.org/jira/browse/HBASE-21012) | Revert the change of serializing TimeRangeTracker | Critical | . |
+| [HBASE-20813](https://issues.apache.org/jira/browse/HBASE-20813) | Remove RPC quotas when the associated table/Namespace is dropped off | Minor | . |
+| [HBASE-20885](https://issues.apache.org/jira/browse/HBASE-20885) | Remove entry for RPC quota from hbase:quota when RPC quota is removed. | Minor | . |
+| [HBASE-20893](https://issues.apache.org/jira/browse/HBASE-20893) | Data loss if splitting region while ServerCrashProcedure executing | Major | . |
+| [HBASE-20950](https://issues.apache.org/jira/browse/HBASE-20950) | Helper method to configure secure DFS cluster for tests | Major | test |
+| [HBASE-19369](https://issues.apache.org/jira/browse/HBASE-19369) | HBase Should use Builder Pattern to Create Log Files while using WAL on Erasure Coding | Major | . |
+| [HBASE-20939](https://issues.apache.org/jira/browse/HBASE-20939) | There will be race when we call suspendIfNotReady and then throw ProcedureSuspendedException | Critical | amv2 |
+| [HBASE-20921](https://issues.apache.org/jira/browse/HBASE-20921) | Possible NPE in ReopenTableRegionsProcedure | Major | amv2 |
+| [HBASE-20867](https://issues.apache.org/jira/browse/HBASE-20867) | RS may get killed while master restarts | Major | . |
+| [HBASE-20878](https://issues.apache.org/jira/browse/HBASE-20878) | Data loss if merging regions while ServerCrashProcedure executing | Critical | amv2 |
+| [HBASE-20846](https://issues.apache.org/jira/browse/HBASE-20846) | Restore procedure locks when master restarts | Major | . |
+| [HBASE-20914](https://issues.apache.org/jira/browse/HBASE-20914) | Trim Master memory usage | Major | Balancer, master |
+| [HBASE-20853](https://issues.apache.org/jira/browse/HBASE-20853) | Polish "Add defaults to Table Interface so Implementors don't have to" | Major | API |
+| [HBASE-20875](https://issues.apache.org/jira/browse/HBASE-20875) | MemStoreLABImp::copyIntoCell uses 7% CPU when writing | Major | Performance |
+| [HBASE-20860](https://issues.apache.org/jira/browse/HBASE-20860) | Merged region's RIT state may not be cleaned after master restart | Major | . |
+| [HBASE-20847](https://issues.apache.org/jira/browse/HBASE-20847) | The parent procedure of RegionTransitionProcedure may not have the table lock | Major | proc-v2, Region Assignment |
+| [HBASE-20776](https://issues.apache.org/jira/browse/HBASE-20776) | Update branch-2 version to 2.2.0-SNAPSHOT | Major | build |
+
+
+### OTHER:
+
+| JIRA | Summary | Priority | Component |
+|:---- |:---- | :--- |:---- |
+| [HBASE-21612](https://issues.apache.org/jira/browse/HBASE-21612) | Add developer debug options in HBase Config for REST server | Minor | Operability, REST, scripts |
+| [HBASE-18735](https://issues.apache.org/jira/browse/HBASE-18735) | Provide a fast mechanism for shutting down mini cluster | Major | . |
+| [HBASE-21489](https://issues.apache.org/jira/browse/HBASE-21489) | TestShell is broken | Major | shell |
+| [HBASE-20152](https://issues.apache.org/jira/browse/HBASE-20152) | [AMv2] DisableTableProcedure versus ServerCrashProcedure | Major | amv2 |
+| [HBASE-20540](https://issues.apache.org/jira/browse/HBASE-20540) | [umbrella] Hadoop 3 compatibility | Major | . |
+| [HBASE-22406](https://issues.apache.org/jira/browse/HBASE-22406) | skip generating rdoc when building gems in our docker image for running yetus | Critical | build, test |
+| [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | Fix completebulkload usage instructions | Trivial | documentation, mapreduce |
+| [HBASE-22375](https://issues.apache.org/jira/browse/HBASE-22375) | Promote AccessChecker to LimitedPrivate(Coprocessor) | Minor | Coprocessors, security |
+| [HBASE-21714](https://issues.apache.org/jira/browse/HBASE-21714) | Deprecated isTableAvailableWithSplit method in thrift module | Major | Thrift |
+| [HBASE-22359](https://issues.apache.org/jira/browse/HBASE-22359) | Backport of HBASE-21371 misses activation-api license information | Minor | build, community |
+| [HBASE-22174](https://issues.apache.org/jira/browse/HBASE-22174) | Remove error prone from our precommit javac check | Major | build |
+| [HBASE-22231](https://issues.apache.org/jira/browse/HBASE-22231) | Remove unused and \* imports | Minor | . |
+| [HBASE-22304](https://issues.apache.org/jira/browse/HBASE-22304) | Fix remaining Checkstyle issues in hbase-endpoint | Trivial | . |
+| [HBASE-22020](https://issues.apache.org/jira/browse/HBASE-22020) | upgrade to yetus 0.9.0 | Major | build, community |
+| [HBASE-22187](https://issues.apache.org/jira/browse/HBASE-22187) | Remove usage of deprecated ClusterConnection.clearRegionCache | Trivial | Client |
+| [HBASE-22203](https://issues.apache.org/jira/browse/HBASE-22203) | Reformat DemoClient.java | Trivial | . |
+| [HBASE-22189](https://issues.apache.org/jira/browse/HBASE-22189) | Remove usage of StoreFile.getModificationTimeStamp | Trivial | . |
+| [HBASE-22108](https://issues.apache.org/jira/browse/HBASE-22108) | Avoid passing null in Admin methods | Major | Admin |
+| [HBASE-22007](https://issues.apache.org/jira/browse/HBASE-22007) | Add restoreSnapshot and cloneSnapshot with acl methods in AsyncAdmin | Major | Admin, asyncclient, Client |
+| [HBASE-22131](https://issues.apache.org/jira/browse/HBASE-22131) | Delete the patches in hbase-protocol-shaded module | Major | build, Protobufs |
+| [HBASE-22099](https://issues.apache.org/jira/browse/HBASE-22099) | Backport HBASE-21895 "Error prone upgrade" to branch-2 | Major | build |
+| [HBASE-22052](https://issues.apache.org/jira/browse/HBASE-22052) | pom cleaning; filter out jersey-core in hadoop2 to match hadoop3 and remove redunant version specifications | Major | . |
+| [HBASE-22065](https://issues.apache.org/jira/browse/HBASE-22065) | Add listTableDescriptors(List\<TableName\>) method in AsyncAdmin | Major | Admin |
+| [HBASE-22042](https://issues.apache.org/jira/browse/HBASE-22042) | Missing @Override annotation for RawAsyncTableImpl.scan | Major | asyncclient, Client |
+| [HBASE-21057](https://issues.apache.org/jira/browse/HBASE-21057) | upgrade to latest spotbugs | Minor | community, test |
+| [HBASE-21888](https://issues.apache.org/jira/browse/HBASE-21888) | Add a isClosed method to AsyncConnection | Major | asyncclient, Client |
+| [HBASE-21884](https://issues.apache.org/jira/browse/HBASE-21884) | Fix box/unbox findbugs warning in secure bulk load | Minor | . |
+| [HBASE-21859](https://issues.apache.org/jira/browse/HBASE-21859) | Add clearRegionLocationCache method for AsyncConnection | Major | asyncclient, Client |
+| [HBASE-21853](https://issues.apache.org/jira/browse/HBASE-21853) | update copyright notices to 2019 | Major | documentation |
+| [HBASE-21791](https://issues.apache.org/jira/browse/HBASE-21791) | Upgrade thrift dependency to 0.12.0 | Blocker | Thrift |
+| [HBASE-21710](https://issues.apache.org/jira/browse/HBASE-21710) | Add quota related methods to the Admin interface | Major | . |
+| [HBASE-21782](https://issues.apache.org/jira/browse/HBASE-21782) | LoadIncrementalHFiles should not be IA.Public | Major | mapreduce |
+| [HBASE-21762](https://issues.apache.org/jira/browse/HBASE-21762) | Move some methods in ClusterConnection to Connection | Major | Client |
+| [HBASE-21715](https://issues.apache.org/jira/browse/HBASE-21715) | Do not throw UnsupportedOperationException in ProcedureFuture.get | Major | Client |
+| [HBASE-21716](https://issues.apache.org/jira/browse/HBASE-21716) | Add toStringCustomizedValues to TableDescriptor | Major | . |
+| [HBASE-21731](https://issues.apache.org/jira/browse/HBASE-21731) | Do not need to use ClusterConnection in IntegrationTestBigLinkedListWithVisibility | Major | . |
+| [HBASE-21685](https://issues.apache.org/jira/browse/HBASE-21685) | Change repository urls to Gitbox | Critical | . |
+| [HBASE-21534](https://issues.apache.org/jira/browse/HBASE-21534) | TestAssignmentManager is flakey | Major | test |
+| [HBASE-21541](https://issues.apache.org/jira/browse/HBASE-21541) | Move MetaTableLocator.verifyRegionLocation to hbase-rsgroup module | Major | . |
+| [HBASE-21265](https://issues.apache.org/jira/browse/HBASE-21265) | Split up TestRSGroups | Minor | rsgroup, test |
+| [HBASE-21517](https://issues.apache.org/jira/browse/HBASE-21517) | Move the getTableRegionForRow method from HMaster to TestMaster | Major | test |
+| [HBASE-21281](https://issues.apache.org/jira/browse/HBASE-21281) | Update bouncycastle dependency. | Major | dependencies, test |
+| [HBASE-21198](https://issues.apache.org/jira/browse/HBASE-21198) | Exclude dependency on net.minidev:json-smart | Major | . |
+| [HBASE-21282](https://issues.apache.org/jira/browse/HBASE-21282) | Upgrade to latest jetty 9.2 and 9.3 versions | Major | dependencies |
+| [HBASE-21287](https://issues.apache.org/jira/browse/HBASE-21287) | JVMClusterUtil Master initialization wait time not configurable | Major | test |
+| [HBASE-21168](https://issues.apache.org/jira/browse/HBASE-21168) | BloomFilterUtil uses hardcoded randomness | Trivial | . |
+| [HBASE-20482](https://issues.apache.org/jira/browse/HBASE-20482) | Print a link to the ref guide chapter for the shell during startup | Minor | documentation, shell |
+| [HBASE-20942](https://issues.apache.org/jira/browse/HBASE-20942) | Improve RpcServer TRACE logging | Major | Operability |
+| [HBASE-20989](https://issues.apache.org/jira/browse/HBASE-20989) | Minor, miscellaneous logging fixes | Trivial | logging |
+
+
## Release 2.2.0 - Unreleased (as of 2019-04-28)
### INCOMPATIBLE CHANGES:
diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index be342e9..61e9de9 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -26,6 +26,90 @@ These release notes cover new developer and user-facing incompatibilities, impor
---
+* [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | *Major* | **Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements**
+
+Moving IA.Public class LossyCounting to IA.Private.
+
+
+---
+
+* [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | *Major* | **Update hadoop check versions for hadoop3 in hbase-personality**
+
+Add hadoop 3.0.3, 3.1.1 3.1.2 in our hadoop check jobs.
+
+
+---
+
+* [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | *Major* | **Dump replication queue should show list of wal files ordered chronologically**
+
+The DumpReplicationQueues tool will now list replication queues sorted in chronological order.
+
+
+---
+
+* [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | *Minor* | **Formatting issues in administration section of book**
+
+Fixes a formatting issue in the administration section of the book, where listing indentation were a little bit off.
+
+
+---
+
+* [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | *Major* | **Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks**
+
+Now the default hadoop-two.version has been changed to 2.8.5, and all hadoop versions before 2.8.2(exclude) will not be supported any more.
+
+
+---
+
+* [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | *Trivial* | **Remove extra/useless +**
+
+Removed extra + in HRegion, HStore and LoadIncrementalHFiles for branch-2 and HRegion and HStore for branch-1.
+
+
+---
+
+* [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | *Trivial* | **Fix completebulkload usage instructions**
+
+Added completebulkload short name for BulkLoadHFilesTool to bin/hbase.
+
+
+---
+
+* [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | *Major* | **Upgrade com.yammer.metrics dependency**
+
+Updated metrics core from 3.2.1 to 3.2.6.
+
+
+---
+
+* [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | *Minor* | **Change rubocop configuration for method length**
+
+The rubocop definition for the maximum method length was set to 75.
+
+
+---
+
+* [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | *Minor* | **Fix Markdown for "Voting on Release Candidates" in book**
+
+Fixes the formatting of the "Voting on Release Candidates" to actually show the quote and code formatting of the RAT check.
+
+
+---
+
+* [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | *Minor* | **Change rubocop config for max line length of 100**
+
+The rubocop configuration in the hbase-shell module now allows a line length with 100 characters, instead of 80 as before. For everything before 2.1.5 this change introduces rubocop itself.
+
+
+---
+
+* [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | *Minor* | **Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS**
+
+This change allows the system and superusers to initiate compactions, even when a space quota violation policy disallows compactions from happening. The original intent behind disallowing of compactions was to prevent end-user compactions from creating undue I/O load, not disallowing \*any\* compaction in the system.
+
+
+---
+
* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
@@ -1220,6 +1304,13 @@ These release notes cover new developer and user-facing incompatibilities, impor
---
+* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
+
+Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
+
+
+---
+
* [HBASE-22155](https://issues.apache.org/jira/browse/HBASE-22155) | *Major* | **Move 2.2.0 on to hbase-thirdparty-2.2.0**
Updates libs used internally by hbase via hbase-thirdparty as follows:
@@ -1309,6 +1400,90 @@ These release notes cover new developer and user-facing incompatibilities, impor
---
+* [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | *Major* | **Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements**
+
+Moving IA.Public class LossyCounting to IA.Private.
+
+
+---
+
+* [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | *Major* | **Update hadoop check versions for hadoop3 in hbase-personality**
+
+Add hadoop 3.0.3, 3.1.1 3.1.2 in our hadoop check jobs.
+
+
+---
+
+* [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | *Major* | **Dump replication queue should show list of wal files ordered chronologically**
+
+The DumpReplicationQueues tool will now list replication queues sorted in chronological order.
+
+
+---
+
+* [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | *Minor* | **Formatting issues in administration section of book**
+
+Fixes a formatting issue in the administration section of the book, where listing indentation were a little bit off.
+
+
+---
+
+* [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | *Major* | **Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks**
+
+Now the default hadoop-two.version has been changed to 2.8.5, and all hadoop versions before 2.8.2(exclude) will not be supported any more.
+
+
+---
+
+* [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | *Trivial* | **Remove extra/useless +**
+
+Removed extra + in HRegion, HStore and LoadIncrementalHFiles for branch-2 and HRegion and HStore for branch-1.
+
+
+---
+
+* [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | *Trivial* | **Fix completebulkload usage instructions**
+
+Added completebulkload short name for BulkLoadHFilesTool to bin/hbase.
+
+
+---
+
+* [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | *Major* | **Upgrade com.yammer.metrics dependency**
+
+Updated metrics core from 3.2.1 to 3.2.6.
+
+
+---
+
+* [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | *Minor* | **Change rubocop configuration for method length**
+
+The rubocop definition for the maximum method length was set to 75.
+
+
+---
+
+* [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | *Minor* | **Fix Markdown for "Voting on Release Candidates" in book**
+
+Fixes the formatting of the "Voting on Release Candidates" to actually show the quote and code formatting of the RAT check.
+
+
+---
+
+* [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | *Minor* | **Change rubocop config for max line length of 100**
+
+The rubocop configuration in the hbase-shell module now allows a line length with 100 characters, instead of 80 as before. For everything before 2.1.5 this change introduces rubocop itself.
+
+
+---
+
+* [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | *Minor* | **Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS**
+
+This change allows the system and superusers to initiate compactions, even when a space quota violation policy disallows compactions from happening. The original intent behind disallowing of compactions was to prevent end-user compactions from creating undue I/O load, not disallowing \*any\* compaction in the system.
+
+
+---
+
* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
@@ -2578,6 +2753,26 @@ bulkload (HFileOutputFormat2) support config the compression on client ,you can
---
+* [HBASE-22000](https://issues.apache.org/jira/browse/HBASE-22000) | *Major* | **Deprecated isTableAvailable with splitKeys**
+
+Deprecated AsyncTable.isTableAvailable(TableName, byte[][]).
+
+
+---
+
+* [HBASE-21871](https://issues.apache.org/jira/browse/HBASE-21871) | *Major* | **Support to specify a peer table name in VerifyReplication tool**
+
+After HBASE-21871, we can specify a peer table name with --peerTableName in VerifyReplication tool like the following:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable 5 TestTable
+
+In addition, we can compare any 2 tables in any remote clusters with specifying both peerId and --peerTableName.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable zk1,zk2,zk3:2181/hbase TestTable
+
+
+---
+
* [HBASE-15728](https://issues.apache.org/jira/browse/HBASE-15728) | *Major* | **Add remaining per-table region / store / flush / compaction related metrics**
Adds below flush, split, and compaction metrics
@@ -3060,6 +3255,90 @@ These release notes cover new developer and user-facing incompatibilities, impor
---
+* [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | *Major* | **Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements**
+
+Moving IA.Public class LossyCounting to IA.Private.
+
+
+---
+
+* [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | *Major* | **Update hadoop check versions for hadoop3 in hbase-personality**
+
+Add hadoop 3.0.3, 3.1.1 3.1.2 in our hadoop check jobs.
+
+
+---
+
+* [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | *Major* | **Dump replication queue should show list of wal files ordered chronologically**
+
+The DumpReplicationQueues tool will now list replication queues sorted in chronological order.
+
+
+---
+
+* [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | *Minor* | **Formatting issues in administration section of book**
+
+Fixes a formatting issue in the administration section of the book, where listing indentation were a little bit off.
+
+
+---
+
+* [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | *Major* | **Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks**
+
+Now the default hadoop-two.version has been changed to 2.8.5, and all hadoop versions before 2.8.2(exclude) will not be supported any more.
+
+
+---
+
+* [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | *Trivial* | **Remove extra/useless +**
+
+Removed extra + in HRegion, HStore and LoadIncrementalHFiles for branch-2 and HRegion and HStore for branch-1.
+
+
+---
+
+* [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | *Trivial* | **Fix completebulkload usage instructions**
+
+Added completebulkload short name for BulkLoadHFilesTool to bin/hbase.
+
+
+---
+
+* [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | *Major* | **Upgrade com.yammer.metrics dependency**
+
+Updated metrics core from 3.2.1 to 3.2.6.
+
+
+---
+
+* [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | *Minor* | **Change rubocop configuration for method length**
+
+The rubocop definition for the maximum method length was set to 75.
+
+
+---
+
+* [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | *Minor* | **Fix Markdown for "Voting on Release Candidates" in book**
+
+Fixes the formatting of the "Voting on Release Candidates" to actually show the quote and code formatting of the RAT check.
+
+
+---
+
+* [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | *Minor* | **Change rubocop config for max line length of 100**
+
+The rubocop configuration in the hbase-shell module now allows a line length with 100 characters, instead of 80 as before. For everything before 2.1.5 this change introduces rubocop itself.
+
+
+---
+
+* [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | *Minor* | **Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS**
+
+This change allows the system and superusers to initiate compactions, even when a space quota violation policy disallows compactions from happening. The original intent behind disallowing of compactions was to prevent end-user compactions from creating undue I/O load, not disallowing \*any\* compaction in the system.
+
+
+---
+
* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
@@ -4310,6 +4589,90 @@ These release notes cover new developer and user-facing incompatibilities, impor
---
+* [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | *Major* | **Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements**
+
+Moving IA.Public class LossyCounting to IA.Private.
+
+
+---
+
+* [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | *Major* | **Update hadoop check versions for hadoop3 in hbase-personality**
+
+Add hadoop 3.0.3, 3.1.1 3.1.2 in our hadoop check jobs.
+
+
+---
+
+* [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | *Major* | **Dump replication queue should show list of wal files ordered chronologically**
+
+The DumpReplicationQueues tool will now list replication queues sorted in chronological order.
+
+
+---
+
+* [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | *Minor* | **Formatting issues in administration section of book**
+
+Fixes a formatting issue in the administration section of the book, where listing indentation were a little bit off.
+
+
+---
+
+* [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | *Major* | **Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks**
+
+Now the default hadoop-two.version has been changed to 2.8.5, and all hadoop versions before 2.8.2(exclude) will not be supported any more.
+
+
+---
+
+* [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | *Trivial* | **Remove extra/useless +**
+
+Removed extra + in HRegion, HStore and LoadIncrementalHFiles for branch-2 and HRegion and HStore for branch-1.
+
+
+---
+
+* [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | *Trivial* | **Fix completebulkload usage instructions**
+
+Added completebulkload short name for BulkLoadHFilesTool to bin/hbase.
+
+
+---
+
+* [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | *Major* | **Upgrade com.yammer.metrics dependency**
+
+Updated metrics core from 3.2.1 to 3.2.6.
+
+
+---
+
+* [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | *Minor* | **Change rubocop configuration for method length**
+
+The rubocop definition for the maximum method length was set to 75.
+
+
+---
+
+* [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | *Minor* | **Fix Markdown for "Voting on Release Candidates" in book**
+
+Fixes the formatting of the "Voting on Release Candidates" to actually show the quote and code formatting of the RAT check.
+
+
+---
+
+* [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | *Minor* | **Change rubocop config for max line length of 100**
+
+The rubocop configuration in the hbase-shell module now allows a line length with 100 characters, instead of 80 as before. For everything before 2.1.5 this change introduces rubocop itself.
+
+
+---
+
+* [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | *Minor* | **Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS**
+
+This change allows the system and superusers to initiate compactions, even when a space quota violation policy disallows compactions from happening. The original intent behind disallowing of compactions was to prevent end-user compactions from creating undue I/O load, not disallowing \*any\* compaction in the system.
+
+
+---
+
* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
@@ -5671,6 +6034,227252 @@ These release notes cover new developer and user-facing incompatibilities, impor
---
+* [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | *Major* | **Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements**
+
+Moving IA.Public class LossyCounting to IA.Private.
+
+
+---
+
+* [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | *Major* | **Update hadoop check versions for hadoop3 in hbase-personality**
+
+Add hadoop 3.0.3, 3.1.1 3.1.2 in our hadoop check jobs.
+
+
+---
+
+* [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | *Major* | **Dump replication queue should show list of wal files ordered chronologically**
+
+The DumpReplicationQueues tool will now list replication queues sorted in chronological order.
+
+
+---
+
+* [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | *Minor* | **Formatting issues in administration section of book**
+
+Fixes a formatting issue in the administration section of the book, where listing indentation were a little bit off.
+
+
+---
+
+* [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | *Major* | **Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks**
+
+Now the default hadoop-two.version has been changed to 2.8.5, and all hadoop versions before 2.8.2(exclude) will not be supported any more.
+
+
+---
+
+* [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | *Trivial* | **Remove extra/useless +**
+
+Removed extra + in HRegion, HStore and LoadIncrementalHFiles for branch-2 and HRegion and HStore for branch-1.
+
+
+---
+
+* [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | *Trivial* | **Fix completebulkload usage instructions**
+
+Added completebulkload short name for BulkLoadHFilesTool to bin/hbase.
+
+
+---
+
+* [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | *Major* | **Upgrade com.yammer.metrics dependency**
+
+Updated metrics core from 3.2.1 to 3.2.6.
+
+
+---
+
+* [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | *Minor* | **Change rubocop configuration for method length**
+
+The rubocop definition for the maximum method length was set to 75.
+
+
+---
+
+* [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | *Minor* | **Fix Markdown for "Voting on Release Candidates" in book**
+
+Fixes the formatting of the "Voting on Release Candidates" to actually show the quote and code formatting of the RAT check.
+
+
+---
+
+* [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | *Minor* | **Change rubocop config for max line length of 100**
+
+The rubocop configuration in the hbase-shell module now allows a line length with 100 characters, instead of 80 as before. For everything before 2.1.5 this change introduces rubocop itself.
+
+
+---
+
+* [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | *Minor* | **Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS**
+
+This change allows the system and superusers to initiate compactions, even when a space quota violation policy disallows compactions from happening. The original intent behind disallowing of compactions was to prevent end-user compactions from creating undue I/O load, not disallowing \*any\* compaction in the system.
+
+
+---
+
+* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
+
+Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
+
+
+---
+
+* [HBASE-22155](https://issues.apache.org/jira/browse/HBASE-22155) | *Major* | **Move 2.2.0 on to hbase-thirdparty-2.2.0**
+
+ Updates libs used internally by hbase via hbase-thirdparty as follows:
+
+ gson 2.8.1 -\\\> 2.8.5
+ guava 22.0 -\\\> 27.1-jre
+ pb 3.5.1 -\\\> 3.7.0
+ netty 4.1.17 -\\\> 4.1.34
+ commons-collections4 4.1 -\\\> 4.3
+
+
+---
+
+* [HBASE-22178](https://issues.apache.org/jira/browse/HBASE-22178) | *Major* | **Introduce a createTableAsync with TableDescriptor method in Admin**
+
+Introduced
+
+Future\<Void\> createTableAsync(TableDescriptor);
+
+
+---
+
+* [HBASE-22108](https://issues.apache.org/jira/browse/HBASE-22108) | *Major* | **Avoid passing null in Admin methods**
+
+Introduced these methods:
+void move(byte[]);
+void move(byte[], ServerName);
+Future\<Void\> splitRegionAsync(byte[]);
+
+These methods are deprecated:
+void move(byte[], byte[])
+
+
+---
+
+* [HBASE-22152](https://issues.apache.org/jira/browse/HBASE-22152) | *Major* | **Create a jenkins file for yetus to processing GitHub PR**
+
+Add a new jenkins file for running pre commit check for GitHub PR.
+
+
+---
+
+* [HBASE-22007](https://issues.apache.org/jira/browse/HBASE-22007) | *Major* | **Add restoreSnapshot and cloneSnapshot with acl methods in AsyncAdmin**
+
+Add cloneSnapshot/restoreSnapshot with acl methods in AsyncAdmin.
+
+
+---
+
+* [HBASE-22123](https://issues.apache.org/jira/browse/HBASE-22123) | *Minor* | **REST gateway reports Insufficient permissions exceptions as 404 Not Found**
+
+When insufficient permissions, you now get:
+
+HTTP/1.1 403 Forbidden
+
+on the HTTP side, and in the message
+
+Forbidden
+org.apache.hadoop.hbase.security.AccessDeniedException: org.apache.hadoop.hbase.security.AccessDeniedException: Insufficient permissions for user ‘myuser',action: get, tableName:mytable, family:cf.
+at org.apache.ranger.authorization.hbase.RangerAuthorizationCoprocessor.authorizeAccess(RangerAuthorizationCoprocessor.java:547)
+and the rest of the ADE stack
+
+
+---
+
+* [HBASE-22100](https://issues.apache.org/jira/browse/HBASE-22100) | *Minor* | **False positive for error prone warnings in pre commit job**
+
+Now we will sort the javac WARNING/ERROR before generating diff in pre-commit so we can get a stable output for the error prone. The downside is that we just sort the output lexicographically so the line number will also be sorted lexicographically, which is a bit strange to human.
+
+
+---
+
+* [HBASE-22057](https://issues.apache.org/jira/browse/HBASE-22057) | *Major* | **Impose upper-bound on size of ZK ops sent in a single multi()**
+
+Exposes a new configuration property "zookeeper.multi.max.size" which dictates the maximum size of deletes that HBase will make to ZooKeeper in a single RPC. This property defaults to 1MB, which should fall beneath the default ZooKeeper limit of 2MB, controlled by "jute.maxbuffer".
+
+
+---
+
+* [HBASE-22052](https://issues.apache.org/jira/browse/HBASE-22052) | *Major* | **pom cleaning; filter out jersey-core in hadoop2 to match hadoop3 and remove redunant version specifications**
+
+<!-- markdown -->
+Fixed awkward dependency issue that prevented site building.
+
+#### note specific to HBase 2.1.4
+HBase 2.1.4 shipped with an early version of this fix that incorrectly altered the libraries included in our binary assembly for using Apache Hadoop 2.7 (the current build default Hadoop version for 2.1.z). For folks running out of the box against a Hadoop 2.7 cluster (or folks who skip the installation step of [replacing the bundled Hadoop libraries](http://hbase.apache.org/book.html#hadoop)) this will result in a failure at Region Server startup due to a missing class definition. e.g.:
+```
+2019-03-27 09:02:05,779 ERROR [main] regionserver.HRegionServer: Failed construction RegionServer
+java.lang.NoClassDefFoundError: org/apache/htrace/SamplerBuilder
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:644)
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:628)
+ at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
+ at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)
+ at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:93)
+ at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2701)
+ at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2683)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:372)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:171)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:356)
+ at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getRootDir(CommonFSUtils.java:362)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.isValidWALRootDir(CommonFSUtils.java:411)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getWALRootDir(CommonFSUtils.java:387)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.initializeFileSystem(HRegionServer.java:704)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.<init>(HRegionServer.java:613)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
+ at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
+ at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.constructRegionServer(HRegionServer.java:3029)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.start(HRegionServerCommandLine.java:63)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.run(HRegionServerCommandLine.java:87)
+ at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
+ at org.apache.hadoop.hbase.util.ServerCommandLine.doMain(ServerCommandLine.java:149)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.main(HRegionServer.java:3047)
+Caused by: java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
+ at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
+ at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
+ ... 26 more
+
+```
+
+Workaround via any _one_ of the following:
+* If you are running against a Hadoop cluster that is 2.8+, ensure you replace the Hadoop libaries in the default binary assembly with those for your version.
+* If you are running against a Hadoop cluster that is 2.8+, build the binary assembly from the source release while specifying your Hadoop version.
+* If you are running against a Hadoop cluster that is a supported 2.7 release, ensure the `hadoop` executable is in the `PATH` seen at Region Server startup and that you are not using the `HBASE_DISABLE_HADOOP_CLASSPATH_LOOKUP` bypass.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers via the HBASE_CLASSPATH environment variable.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers by copying it into the directory `${HBASE_HOME}/lib/client-facing-thirdparty/`.
+
+
+---
+
+* [HBASE-22065](https://issues.apache.org/jira/browse/HBASE-22065) | *Major* | **Add listTableDescriptors(List\<TableName\>) method in AsyncAdmin**
+
+Add a listTableDescriptors(List\<TableName\>) method in the AsyncAdmin interface, to align with the Admin interface.
+
+
+---
+
+* [HBASE-22040](https://issues.apache.org/jira/browse/HBASE-22040) | *Major* | **Add mergeRegionsAsync with a List of region names method in AsyncAdmin**
+
+Add a mergeRegionsAsync(byte[][], boolean) method in the AsyncAdmin interface.
+
+Instead of using assert, now we will throw IllegalArgumentException when you want to merge less than 2 regions at client side. And also, at master side, instead of using assert, now we will throw DoNotRetryIOException if you want merge more than 2 regions, since we only support merging two regions at once for now.
+
+
+---
+
+* [HBASE-22039](https://issues.apache.org/jira/browse/HBASE-22039) | *Major* | **Should add the synchronous parameter for the XXXSwitch method in AsyncAdmin**
+
+Add drainXXX parameter for balancerSwitch/splitSwitch/mergeSwitch methods in the AsyncAdmin interface, which has the same meaning with the synchronous parameter for these methods in the Admin interface.
+
+
+---
+
+* [HBASE-21810](https://issues.apache.org/jira/browse/HBASE-21810) | *Major* | **bulkload support set hfile compression on client**
+
+bulkload (HFileOutputFormat2) support config the compression on client ,you can set the job configuration "hbase.mapreduce.hfileoutputformat.compression" override the auto-detection of the target table's compression
+
+
+---
+
+* [HBASE-22000](https://issues.apache.org/jira/browse/HBASE-22000) | *Major* | **Deprecated isTableAvailable with splitKeys**
+
+Deprecated AsyncTable.isTableAvailable(TableName, byte[][]).
+
+
+---
+
+* [HBASE-21871](https://issues.apache.org/jira/browse/HBASE-21871) | *Major* | **Support to specify a peer table name in VerifyReplication tool**
+
+After HBASE-21871, we can specify a peer table name with --peerTableName in VerifyReplication tool like the following:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable 5 TestTable
+
+In addition, we can compare any 2 tables in any remote clusters with specifying both peerId and --peerTableName.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable zk1,zk2,zk3:2181/hbase TestTable
+
+
+---
+
+* [HBASE-15728](https://issues.apache.org/jira/browse/HBASE-15728) | *Major* | **Add remaining per-table region / store / flush / compaction related metrics**
+
+Adds below flush, split, and compaction metrics
+
+ + // split related metrics
+ + private MutableFastCounter splitRequest;
+ + private MutableFastCounter splitSuccess;
+ + private MetricHistogram splitTimeHisto;
+ +
+ + // flush related metrics
+ + private MetricHistogram flushTimeHisto;
+ + private MetricHistogram flushMemstoreSizeHisto;
+ + private MetricHistogram flushOutputSizeHisto;
+ + private MutableFastCounter flushedMemstoreBytes;
+ + private MutableFastCounter flushedOutputBytes;
+ +
+ + // compaction related metrics
+ + private MetricHistogram compactionTimeHisto;
+ + private MetricHistogram compactionInputFileCountHisto;
+ + private MetricHistogram compactionInputSizeHisto;
+ + private MetricHistogram compactionOutputFileCountHisto;
+ + private MetricHistogram compactionOutputSizeHisto;
+ + private MutableFastCounter compactedInputBytes;
+ + private MutableFastCounter compactedOutputBytes;
+ +
+ + private MetricHistogram majorCompactionTimeHisto;
+ + private MetricHistogram majorCompactionInputFileCountHisto;
+ + private MetricHistogram majorCompactionInputSizeHisto;
+ + private MetricHistogram majorCompactionOutputFileCountHisto;
+ + private MetricHistogram majorCompactionOutputSizeHisto;
+ + private MutableFastCounter majorCompactedInputBytes;
+ + private MutableFastCounter majorCompactedOutputBytes;
+
+
+---
+
+* [HBASE-20886](https://issues.apache.org/jira/browse/HBASE-20886) | *Critical* | **[Auth] Support keytab login in hbase client**
+
+From 2.2.0, hbase supports client login via keytab. To use this feature, client should specify \`hbase.client.keytab.file\` and \`hbase.client.keytab.principal\` in hbase-site.xml, then the connection will contain the needed credentials which be renewed periodically to communicate with kerberized hbase cluster.
+
+
+---
+
+* [HBASE-21410](https://issues.apache.org/jira/browse/HBASE-21410) | *Major* | **A helper page that help find all problematic regions and procedures**
+
+After HBASE-21410, we add a helper page to Master UI. This helper page is mainly to help HBase operator quickly found all regions and pids that are get stuck.
+There are 2 entries to get in this page.
+One is showing in the Regions in Transition section, it made "num region(s) in transition" a link that you can click and check all regions in transition and their related procedure IDs.
+The other one is showing in the table details section, it made the number of CLOSING or OPENING regions a link, which you can click and check regions and related procedure IDs of CLOSING or OPENING regions of a certain table.
+In this helper page, not only you can see all regions and related procedures, there are 2 buttons at the top which will show these regions or procedure IDs in text format. This is mainly aim to help operator to easily copy and paste all problematic procedure IDs and encoded region names to HBCK2's command line, by which we HBase operator can bypass these procedures or assign these regions.
+
+
+---
+
+* [HBASE-21588](https://issues.apache.org/jira/browse/HBASE-21588) | *Major* | **Procedure v2 wal splitting implementation**
+
+After HBASE-21588, we introduce a new way to do WAL splitting coordination by procedure framework. This can simplify the process of WAL splitting and no need to connect zookeeper any more.
+During ServerCrashProcedure, it will create a SplitWALProcedure for each WAL that need to split. Then each SplitWALProcedure will spawn a SplitWALRemoteProcedure to send the request to regionserver.
+At the RegionServer side, whole process is handled by SplitWALCallable. It split the WAL and return the result to master.
+According to my test, this patch has a better performance as the number of WALs that need to split increase. And it can relieve the pressure on zookeeper.
+
+
+---
+
+* [HBASE-20734](https://issues.apache.org/jira/browse/HBASE-20734) | *Major* | **Colocate recovered edits directory with hbase.wal.dir**
+
+Previously the recovered.edits directory was under the root directory. This JIRA moves the recovered.edits directory to be under the hbase.wal.dir if set. It also adds a check for any recovered.edits found under the root directory for backwards compatibility. This gives improvements when a faster media(like SSD) or more local FileSystem is used for the hbase.wal.dir than the root dir.
+
+
+---
+
+* [HBASE-20401](https://issues.apache.org/jira/browse/HBASE-20401) | *Minor* | **Make \`MAX\_WAIT\` and \`waitIfNotFinished\` in CleanerContext configurable**
+
+When oldwals (and hfile) cleaner cleans stale wals (and hfiles), it will periodically check and wait the clean results from filesystem, the total wait time will be no more than a max time.
+
+The periodically wait and check configurations are hbase.oldwals.cleaner.thread.check.interval.msec (default is 500 ms) and hbase.regionserver.hfilecleaner.thread.check.interval.msec (default is 1000 ms).
+
+Meanwhile, The max time configurations are hbase.oldwals.cleaner.thread.timeout.msec and hbase.regionserver.hfilecleaner.thread.timeout.msec, they are set to 60 seconds by default.
+
+All support dynamic configuration.
+
+e.g. in the oldwals cleaning scenario, one may consider tuning hbase.oldwals.cleaner.thread.timeout.msec and hbase.oldwals.cleaner.thread.check.interval.msec
+
+1. While deleting a oldwal never complete (strange but possible), then delete file task needs to wait for a max of 60 seconds. Here, 60 seconds might be too long, or the opposite way is to increase more than 60 seconds in the use cases of slow file delete.
+2. The check and wait of a file delete is set to default in the period of 500 milliseconds, one might want to tune this checking period to a short interval to check more frequently or to a longer interval to avoid checking too often to manage their delete file task checking period (the longer interval may be use to avoid checking too fast while using a high latency storage).
+
+
+---
+
+* [HBASE-21481](https://issues.apache.org/jira/browse/HBASE-21481) | *Major* | **[acl] Superuser's permissions should not be granted or revoked by any non-su global admin**
+
+HBASE-21481 improves the quality of access control, by strengthening the protection of super users's privileges.
+
+
+---
+
+* [HBASE-21082](https://issues.apache.org/jira/browse/HBASE-21082) | *Critical* | **Reimplement assign/unassign related procedure metrics**
+
+Now we have four types of RIT procedure metrics, assign, unassign, move, reopen. The meaning of assign/unassign is changed, as we will not increase the unassign metric and then the assign metric when moving a region.
+Also introduced two new procedure metrics, open and close, which are used to track the open/close region calls to region server. We may send open/close multiple times to finish a RIT since we may retry multiple times.
+
+
+---
+
+* [HBASE-20724](https://issues.apache.org/jira/browse/HBASE-20724) | *Critical* | **Sometimes some compacted storefiles are still opened after region failover**
+
+Problem: This is an old problem since HBASE-2231. The compaction event marker was only writed to WAL. But after flush, the WAL may be archived, which means an useful compaction event marker be deleted, too. So the compacted store files cannot be archived when region open and replay WAL.
+
+Solution: After this jira, the compaction event tracker will be writed to HFile. When region open and load store files, read the compaction evnet tracker from HFile and archive the compacted store files which still exist.
+
+
+---
+
+* [HBASE-21820](https://issues.apache.org/jira/browse/HBASE-21820) | *Major* | **Implement CLUSTER quota scope**
+
+HBase contains two quota scopes: MACHINE and CLUSTER. Before this patch, set quota operations did not expose scope option to client api and use MACHINE as default, CLUSTER scope can not be set and used.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+
+This issue implements CLUSTER scope in a simple way: For user, namespace, user over namespace quota, use [ClusterLimit / RSNum] as machine limit. For table and user over table quota, use [ClusterLimit / TotalTableRegionNum \* MachineTableRegionNum] as machine limit.
+After this patch, user can set CLUSTER scope quota, but MACHINE is still default if user ignore scope.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> MACHINE
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> CLUSTER
+
+
+---
+
+* [HBASE-21057](https://issues.apache.org/jira/browse/HBASE-21057) | *Minor* | **upgrade to latest spotbugs**
+
+Change spotbugs version to 3.1.11.
+
+
+---
+
+* [HBASE-21922](https://issues.apache.org/jira/browse/HBASE-21922) | *Major* | **BloomContext#sanityCheck may failed when use ROWPREFIX\_DELIMITED bloom filter**
+
+Remove bloom filter type ROWPREFIX\_DELIMITED. May add it back when find a better solution.
+
+
+---
+
+* [HBASE-21783](https://issues.apache.org/jira/browse/HBASE-21783) | *Major* | **Support exceed user/table/ns throttle quota if region server has available quota**
+
+Support enable or disable exceed throttle quota. Exceed throttle quota means, user can over consume user/namespace/table quota if region server has additional available quota because other users don't consume at the same time.
+Use the following shell commands to enable/disable exceed throttle quota: enable\_exceed\_throttle\_quota
+disable\_exceed\_throttle\_quota
+There are two limits when enable exceed throttle quota:
+1. Must set at least one read and one write region server throttle quota;
+2. All region server throttle quotas must be in seconds time unit. Because once previous requests exceed their quota and consume region server quota, quota in other time units may be refilled in a long time, this may affect later requests.
+
+
+---
+
+* [HBASE-20587](https://issues.apache.org/jira/browse/HBASE-20587) | *Major* | **Replace Jackson with shaded thirdparty gson**
+
+Remove jackson dependencies from most hbase modules except hbase-rest, use shaded gson instead. The output json will be a bit different since jackson can use getter/setter, but gson will always use the fields.
+
+
+---
+
+* [HBASE-21928](https://issues.apache.org/jira/browse/HBASE-21928) | *Major* | **Deprecated HConstants.META\_QOS**
+
+Mark HConstants.META\_QOS as deprecated. It is for internal use only, which is the highest priority. You should not try to set a priority greater than or equal to this value, although it is no harm but also useless.
+
+
+---
+
+* [HBASE-17942](https://issues.apache.org/jira/browse/HBASE-17942) | *Major* | **Disable region splits and merges per table**
+
+This patch adds the ability to disable split and/or merge for a table (By default, split and merge are enabled for a table).
+
+
+---
+
+* [HBASE-21636](https://issues.apache.org/jira/browse/HBASE-21636) | *Major* | **Enhance the shell scan command to support missing scanner specifications like ReadType, IsolationLevel etc.**
+
+Allows shell to set Scan options previously not exposed. See additions as part of the scan help by typing following hbase shell:
+
+hbase\> help 'scan'
+
+
+---
+
+* [HBASE-21201](https://issues.apache.org/jira/browse/HBASE-21201) | *Major* | **Support to run VerifyReplication MR tool without peerid**
+
+We can specify peerQuorumAddress instead of peerId in VerifyReplication tool. So it no longer requires peerId to be setup when using this tool.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication zk1,zk2,zk3:2181/hbase testTable
+
+
+---
+
+* [HBASE-21838](https://issues.apache.org/jira/browse/HBASE-21838) | *Major* | **Create a special ReplicationEndpoint just for verifying the WAL entries are fine**
+
+Introduce a VerifyWALEntriesReplicationEndpoint which replicates nothing but only verifies if all the cells are valid.
+It can be used to capture bugs for writing WAL, as most times we will not read the WALs again after writing it if there are no region server crashes.
+
+
+---
+
+* [HBASE-21727](https://issues.apache.org/jira/browse/HBASE-21727) | *Minor* | **Simplify documentation around client timeout**
+
+Deprecated HBaseConfiguration#getInt(Configuration, String, String, int) method and removed it from 3.0.0 version.
+
+
+---
+
+* [HBASE-21764](https://issues.apache.org/jira/browse/HBASE-21764) | *Major* | **Size of in-memory compaction thread pool should be configurable**
+
+Introduced an new config key in this issue: hbase.regionserver.inmemory.compaction.pool.size. the default value would be 10. you can configure this to set the pool size of in-memory compaction pool. Note that all memstores in one region server will share the same pool, so if you have many regions in one region server, you need to set this larger to compact faster for better read performance.
+
+
+---
+
+* [HBASE-21684](https://issues.apache.org/jira/browse/HBASE-21684) | *Major* | **Throw DNRIOE when connection or rpc client is closed**
+
+Make StoppedRpcClientException extend DoNotRetryIOException.
+
+
+---
+
+* [HBASE-21739](https://issues.apache.org/jira/browse/HBASE-21739) | *Major* | **Move grant/revoke from regionserver to master**
+
+To implement user permission control in Precedure V2, move grant and revoke method from AccessController to master firstly.
+Mark AccessController#grant and AccessController#revoke as deprecated and please use Admin#grant and Admin#revoke instead.
+
+
+---
+
+* [HBASE-21791](https://issues.apache.org/jira/browse/HBASE-21791) | *Blocker* | **Upgrade thrift dependency to 0.12.0**
+
+IMPORTANT: Due to security issues, all users who use hbase thrift should avoid using releases which do not have this fix.
+
+The effect releases are:
+2.1.x: 2.1.2 and below
+2.0.x: 2.0.4 and below
+1.x: 1.4.x and below
+
+If you are using the effect releases above, please consider upgrading to a newer release ASAP.
+
+
+---
+
+* [HBASE-21792](https://issues.apache.org/jira/browse/HBASE-21792) | *Major* | **Mark HTableMultiplexer as deprecated and remove it in 3.0.0**
+
+HTableMultiplexer exposes the implementation class, and it is incomplete, so we mark it as deprecated and remove it in 3.0.0 release.
+
+There is no direct replacement for HTableMultiplexer, please use BufferedMutator if you want to batch mutations to a table.
+
+
+---
+
+* [HBASE-21782](https://issues.apache.org/jira/browse/HBASE-21782) | *Major* | **LoadIncrementalHFiles should not be IA.Public**
+
+Introduce a BulkLoadHFiles interface which is marked as IA.Public, for doing bulk load programmatically.
+Introduce a BulkLoadHFilesTool which extends BulkLoadHFiles, and is marked as IA.LimitedPrivate(TOOLS), for using from command line.
+The old LoadIncrementalHFiles is deprecated and will be removed in 3.0.0.
+
+
+---
+
+* [HBASE-21762](https://issues.apache.org/jira/browse/HBASE-21762) | *Major* | **Move some methods in ClusterConnection to Connection**
+
+Move the two getHbck method from ClusterConnection to Connection, and mark the methods as IA.LimitedPrivate(HBCK), as ClusterConnection is IA.Private and should not be depended by HBCK2.
+
+Add a clearRegionLocationCache method in Connection to clear the region location cache for all the tables. As in RegionLocator, most of the methods have a 'reload' parameter, which implicitly tells user that we have a region location cache, so adding a method to clear the cache is fine.
+
+
+---
+
+* [HBASE-21713](https://issues.apache.org/jira/browse/HBASE-21713) | *Major* | **Support set region server throttle quota**
+
+Support set region server rpc throttle quota which represents the read/write ability of region servers and throttles when region server's total requests exceeding the limit.
+
+Use the following shell command to set RS quota:
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', THROTTLE\_TYPE =\> WRITE, LIMIT =\> '20000req/sec'
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', LIMIT =\> NONE
+"all" represents the throttle quota of all region servers and setting specified region server quota isn't supported currently.
+
+
+---
+
+* [HBASE-21689](https://issues.apache.org/jira/browse/HBASE-21689) | *Minor* | **Make table/namespace specific current quota info available in shell(describe\_namespace & describe)**
+
+In shell commands "describe\_namespace" and "describe", which are used to see the descriptors of the namespaces and tables respectively, quotas set on that particular namespace/table will also be printed along.
+
+
+---
+
+* [HBASE-17370](https://issues.apache.org/jira/browse/HBASE-17370) | *Major* | **Fix or provide shell scripts to drain and decommission region server**
+
+Adds shell support for the following:
+- List decommissioned/draining region servers
+- Decommission a list of region servers, optionally offload corresponding regions
+- Recommission a region server, optionally load a list of passed regions
+
+
+---
+
+* [HBASE-21734](https://issues.apache.org/jira/browse/HBASE-21734) | *Major* | **Some optimization in FilterListWithOR**
+
+After HBASE-21620, the filterListWithOR has been a bit slow because we need to merge each sub-filter's RC , while before HBASE-21620, we will skip many RC merging, but the logic was wrong. So here we choose another way to optimaze the performance: removing the KeyValueUtil#toNewKeyCell.
+Anoop Sam John suggested that the KeyValueUtil#toNewKeyCell can save some GC before because if we copy key part of cell into a single byte[], then the block the cell refering won't be refered by the filter list any more, the upper layer can GC the data block quickly. while after HBASE-21620, we will update the prevCellList for every encountered cell now, so the lifecycle of cell in prevCellList for FilterList will be quite shorter. so just use the cell ref for saving cpu.
+BTW, we removed all the arrays streams usage in filter list, because it's also quite time-consuming in our test.
+
+
+---
+
+* [HBASE-21738](https://issues.apache.org/jira/browse/HBASE-21738) | *Critical* | **Remove all the CSLM#size operation in our memstore because it's an quite time consuming.**
+
+We found the memstore snapshotting would cost much time because of calling the time-consuming ConcurrentSkipListMap#Size, it would make the p999 latency spike happen. So in this issue, we remove all ConcurrentSkipListMap#size in memstore by counting the cellsCount in MemstoreSizeing. As the issue described, the p999 latency spike was mitigated.
+
+
+---
+
+* [HBASE-21034](https://issues.apache.org/jira/browse/HBASE-21034) | *Major* | **Add new throttle type: read/write capacity unit**
+
+Provides a new throttle type: capacity unit. One read/write/request capacity unit represents that read/write/read+write up to 1K data. If data size is more than 1K, then consume additional capacity units.
+
+Use shell command to set capacity unit(CU):
+set\_quota TYPE =\> THROTTLE, THROTTLE\_TYPE =\> WRITE, USER =\> 'u1', LIMIT =\> '10CU/sec'
+
+Use the "hbase.quota.read.capacity.unit" property to set the data size of one read capacity unit in bytes, the default value is 1K. Use the "hbase.quota.write.capacity.unit" property to set the data size of one write capacity unit in bytes, the default value is 1K.
+
+
+---
+
+* [HBASE-21595](https://issues.apache.org/jira/browse/HBASE-21595) | *Minor* | **Print thread's information and stack traces when RS is aborting forcibly**
+
+Does thread dump on stdout on abort.
+
+
+---
+
+* [HBASE-21732](https://issues.apache.org/jira/browse/HBASE-21732) | *Critical* | **Should call toUpperCase before using Enum.valueOf in some methods for ColumnFamilyDescriptor**
+
+Now all the Enum configs in ColumnFamilyDescriptor can accept lower case config value.
+
+
+---
+
+* [HBASE-21712](https://issues.apache.org/jira/browse/HBASE-21712) | *Minor* | **Make submit-patch.py python3 compatible**
+
+Python3 support was added to dev-support/submit-patch.py. To install newly required dependencies run \`pip install -r dev-support/python-requirements.txt\` command.
+
+
+---
+
+* [HBASE-21657](https://issues.apache.org/jira/browse/HBASE-21657) | *Major* | **PrivateCellUtil#estimatedSerializedSizeOf has been the bottleneck in 100% scan case.**
+
+In HBASE-21657, I simplified the path of estimatedSerialiedSize() & estimatedSerialiedSizeOfCell() by moving the general getSerializedSize()
+and heapSize() from ExtendedCell to Cell interface. The patch also included some other improvments:
+
+1. For 99% of case, our cells has no tags, so let the HFileScannerImpl just return the NoTagsByteBufferKeyValue if no tags, which means we can save
+ lots of cpu time when sending no tags cell to rpc because can just return the length instead of getting the serialize size by caculating offset/length
+ of each fields(row/cf/cq..)
+2. Move the subclass's getSerializedSize implementation from ExtendedCell to their own class, which mean we did not need to call ExtendedCell's
+ getSerialiedSize() firstly, then forward to subclass's getSerializedSize(withTags).
+3. Give a estimated result arraylist size for avoiding the frequent list extension when in a big scan, now we estimate the array size as min(scan.rows, 512).
+ it's also help a lot.
+
+We gain almost ~40% throughput improvement in 100% scan case for branch-2 (cacheHitRatio~100%)[1], it's a good thing. While it's a incompatible change in
+some case, such as if the upstream user implemented their own Cells, although it's rare but can happen, then their compile will be error.
+
+
+---
+
+* [HBASE-21647](https://issues.apache.org/jira/browse/HBASE-21647) | *Major* | **Add status track for splitting WAL tasks**
+
+Adds task monitor that shows ServerCrashProcedure progress in UI.
+
+
+---
+
+* [HBASE-21652](https://issues.apache.org/jira/browse/HBASE-21652) | *Major* | **Refactor ThriftServer making thrift2 server inherited from thrift1 server**
+
+Before this issue, thrift1 server and thrift2 server are totally different servers. If a new feature is added to thrift1 server, thrfit2 server have to make the same change to support it(e.g. authorization). After this issue, thrift2 server is inherited from thrift1, thrift2 server now have all the features thrift1 server has(e.g http support, which thrift2 server doesn't have before). The way to start thrift1 or thrift2 server remain the same after this issue.
+
+
+---
+
+* [HBASE-21661](https://issues.apache.org/jira/browse/HBASE-21661) | *Major* | **Provide Thrift2 implementation of Table/Admin**
+
+ThriftAdmin/ThriftTable are implemented based on Thrift2. With ThriftAdmin/ThriftTable, People can use thrift2 protocol just like HTable/HBaseAdmin.
+Example of using ThriftConnection
+Configuration conf = HBaseConfiguration.create();
+conf.set(ClusterConnection.HBASE\_CLIENT\_CONNECTION\_IMPL,ThriftConnection.class.getName());
+Connection conn = ConnectionFactory.createConnection(conf);
+Table table = conn.getTable(tablename)
+It is just like a normal Connection, similar use experience with the default ConnectionImplementation
+
+
+---
+
+* [HBASE-21618](https://issues.apache.org/jira/browse/HBASE-21618) | *Critical* | **Scan with the same startRow(inclusive=true) and stopRow(inclusive=false) returns one result**
+
+There was a bug when scan with the same startRow(inclusive=true) and stopRow(inclusive=false). The old incorrect behavior is return one result. After this fix, the new correct behavior is return nothing.
+
+
+---
+
+* [HBASE-21159](https://issues.apache.org/jira/browse/HBASE-21159) | *Major* | **Add shell command to switch throttle on or off**
+
+Support enable or disable rpc throttle when hbase quota is enabled. If hbase quota is enabled, rpc throttle is enabled by default. When disable rpc throttle, HBase will not throttle any request. Use the following commands to switch rpc throttle : enable\_rpc\_throttle / disable\_rpc\_throttle.
+
+
+---
+
+* [HBASE-21659](https://issues.apache.org/jira/browse/HBASE-21659) | *Minor* | **Avoid to load duplicate coprocessors in system config and table descriptor**
+
+Add a new configuration "hbase.skip.load.duplicate.table.coprocessor". The default value is false to keep compatible with the old behavior. Config it true to skip load duplicate table coprocessor.
+
+
+---
+
+* [HBASE-21650](https://issues.apache.org/jira/browse/HBASE-21650) | *Major* | **Add DDL operation and some other miscellaneous to thrift2**
+
+Added DDL operations and some other structure definition to thrift2. Methods added:
+create/modify/addColumnFamily/deleteColumnFamily/modifyColumnFamily/enable/disable/truncate/delete table
+create/modify/delete namespace
+get(list)TableDescriptor(s)/get(list)NamespaceDescirptor(s)
+tableExists/isTableEnabled/isTableDisabled/isTableAvailabe
+And some class definitions along with those methods
+
+
+---
+
+* [HBASE-21643](https://issues.apache.org/jira/browse/HBASE-21643) | *Major* | **Introduce two new region coprocessor method and deprecated postMutationBeforeWAL**
+
+Deprecated region coprocessor postMutationBeforeWAL and introduce two new region coprocessor postIncrementBeforeWAL and postAppendBeforeWAL instead.
+
+
+---
+
+* [HBASE-21635](https://issues.apache.org/jira/browse/HBASE-21635) | *Major* | **Use maven enforcer to ban imports from illegal packages**
+
+Use de.skuzzle.enforcer.restrict-imports-enforcer-rule extension for maven enforcer plugin to ban illegal imports at compile time. Now if you use illegal imports, for example, import com.google.common.\*, there will be a compile error, instead of a checkstyle warning.
+
+
+---
+
+* [HBASE-21401](https://issues.apache.org/jira/browse/HBASE-21401) | *Critical* | **Sanity check when constructing the KeyValue**
+
+Add a sanity check when constructing KeyValue from a byte[]. we use the constructor when we're reading kv from socket or HFIle or WAL(replication). the santiy check isn't designed for discovering the bits corruption in network transferring or disk IO. It is designed to detect bugs inside HBase in advance. and HBASE-21459 indicated that there's extremely small performance loss for diff kinds of keyvalue.
+
+
+---
+
+* [HBASE-21554](https://issues.apache.org/jira/browse/HBASE-21554) | *Minor* | **Show replication endpoint classname for replication peer on master web UI**
+
+The replication UI on master will show the replication endpoint classname.
+
+
+---
+
+* [HBASE-21549](https://issues.apache.org/jira/browse/HBASE-21549) | *Major* | **Add shell command for serial replication peer**
+
+Add a SERIAL flag for add\_peer command to identifiy whether or not the replication peer is a serial replication peer. The default serial flag is false.
+
+
+---
+
+* [HBASE-21453](https://issues.apache.org/jira/browse/HBASE-21453) | *Major* | **Convert ReadOnlyZKClient to DEBUG instead of INFO**
+
+Log level of ReadOnlyZKClient moved to debug.
+
+
+---
+
+* [HBASE-21283](https://issues.apache.org/jira/browse/HBASE-21283) | *Minor* | **Add new shell command 'rit' for listing regions in transition**
+
+<!-- markdown -->
+
+The HBase `shell` now includes a command to list regions currently in transition.
+
+```
+HBase Shell
+Use "help" to get list of supported commands.
+Use "exit" to quit this interactive shell.
+Version 1.5.0-SNAPSHOT, r9bb6d2fa8b760f16cd046657240ebd4ad91cb6de, Mon Oct 8 21:05:50 UTC 2018
+
+hbase(main):001:0> help 'rit'
+List all regions in transition.
+Examples:
+ hbase> rit
+
+hbase(main):002:0> create ...
+0 row(s) in 2.5150 seconds
+=> Hbase::Table - IntegrationTestBigLinkedList
+
+hbase(main):003:0> rit
+0 row(s) in 0.0340 seconds
+
+hbase(main):004:0> unassign '56f0c38c81ae453d19906ce156a2d6a1'
+0 row(s) in 0.0540 seconds
+
+hbase(main):005:0> rit
+IntegrationTestBigLinkedList,L\xCC\xCC\xCC\xCC\xCC\xCC\xCB,1539117183224.56f0c38c81ae453d19906ce156a2d6a1. state=PENDING_CLOSE, ts=Tue Oct 09 20:33:34 UTC 2018 (0s ago), server=null
+1 row(s) in 0.0170 seconds
+```
+
+
+---
+
+* [HBASE-21567](https://issues.apache.org/jira/browse/HBASE-21567) | *Major* | **Allow overriding configs starting up the shell**
+
+Allow passing of -Dkey=value option to shell to override hbase-\* configuration: e.g.:
+
+$ ./bin/hbase shell -Dhbase.zookeeper.quorum=ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org -Draining=false
+...
+hbase(main):001:0\> @shell.hbase.configuration.get("hbase.zookeeper.quorum")
+=\> "ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org"
+hbase(main):002:0\> @shell.hbase.configuration.get("raining")
+=\> "false"
+
+
+---
+
+* [HBASE-21560](https://issues.apache.org/jira/browse/HBASE-21560) | *Major* | **Return a new TableDescriptor for MasterObserver#preModifyTable to allow coprocessor modify the TableDescriptor**
+
+Incompatible change. Allow MasterObserver#preModifyTable to return a new TableDescriptor. And master will use this returned TableDescriptor to modify table.
+
+
+---
+
+* [HBASE-21551](https://issues.apache.org/jira/browse/HBASE-21551) | *Blocker* | **Memory leak when use scan with STREAM at server side**
+
+<!-- markdown -->
+### Summary
+HBase clusters will experience Region Server failures due to out of memory errors due to a leak given any of the following:
+
+* User initiates Scan operations set to use the STREAM reading type
+* User initiates Scan operations set to use the default reading type that read more than 4 * the block size of column families involved in the scan (e.g. by default 4*64KiB)
+* Compactions run
+
+### Root cause
+
+When there are long running scans the Region Server process attempts to optimize access by using a different API geared towards sequential access. Due to an error in HBASE-20704 for HBase 2.0+ the Region Server fails to release related resources when those scans finish. That same optimization path is always used for the HBase internal file compaction process.
+
+### Workaround
+
+Impact for this error can be minimized by setting the config value “hbase.storescanner.pread.max.bytes” to MAX_INT to avoid the optimization for default user scans. Clients should also be checked to ensure they do not pass the STREAM read type to the Scan API. This will have a severe impact on performance for long scans.
+
+Compactions always use this sequential optimized reading mechanism so downstream users will need to periodically restart Region Server roles after compactions have happened.
+
+
+---
+
+* [HBASE-21550](https://issues.apache.org/jira/browse/HBASE-21550) | *Major* | **Add a new method preCreateTableRegionInfos for MasterObserver which allows CPs to modify the TableDescriptor**
+
+Add a new method preCreateTableRegionInfos for MasterObserver, which will be called before creating region infos for the given table, before the preCreateTable method. It allows you to return a new TableDescritor to override the original one. Returns null or throws exception will stop the creation.
+
+
+---
+
+* [HBASE-21492](https://issues.apache.org/jira/browse/HBASE-21492) | *Critical* | **CellCodec Written To WAL Before It's Verified**
+
+After HBASE-21492 the return type of WALCellCodec#getWALCellCodecClass has been changed from String to Class
+
+
+---
+
+* [HBASE-21387](https://issues.apache.org/jira/browse/HBASE-21387) | *Major* | **Race condition surrounding in progress snapshot handling in snapshot cache leads to loss of snapshot files**
+
+To prevent race condition between in progress snapshot (performed by TakeSnapshotHandler) and HFileCleaner which results in data loss, this JIRA introduced mutual exclusion between taking snapshot and running HFileCleaner. That is, at any given moment, either some snapshot can be taken or, HFileCleaner checks hfiles which are not referenced, but not both can be running.
+
+
+---
+
+* [HBASE-21452](https://issues.apache.org/jira/browse/HBASE-21452) | *Major* | **Illegal character in hbase counters group name**
+
+Changes group name of hbase metrics from "HBase Counters" to "HBaseCounters".
+
+
+---
+
+* [HBASE-21443](https://issues.apache.org/jira/browse/HBASE-21443) | *Major* | **[hbase-connectors] Purge hbase-\* modules from core now they've been moved to hbase-connectors**
+
+Parent issue moved hbase-spark\* modules to hbase-connectors. This issue removes hbase-spark\* modules from hbase core repo.
+
+
+---
+
+* [HBASE-21430](https://issues.apache.org/jira/browse/HBASE-21430) | *Major* | **[hbase-connectors] Move hbase-spark\* modules to hbase-connectors repo**
+
+hbase-spark\* modules have been cloned to https://github.com/apache/hbase-connectors All spark connector dev is to happen in that repo from here on out.
+
+Let me file a subtask to remove hbase-spark\* modules from hbase core.
+
+
+---
+
+* [HBASE-21417](https://issues.apache.org/jira/browse/HBASE-21417) | *Critical* | **Pre commit build is broken due to surefire plugin crashes**
+
+Add -Djdk.net.URLClassPath.disableClassPathURLCheck=true when executing surefire plugin.
+
+
+---
+
+* [HBASE-21191](https://issues.apache.org/jira/browse/HBASE-21191) | *Major* | **Add a holding-pattern if no assign for meta or namespace (Can happen if masterprocwals have been cleared).**
+
+Puts master startup into holding pattern if meta is not assigned (previous it would exit). To make progress again, operator needs to inject an assign (Caveats and instruction can be found in HBASE-21035).
+
+
+---
+
+* [HBASE-21322](https://issues.apache.org/jira/browse/HBASE-21322) | *Critical* | **Add a scheduleServerCrashProcedure() API to HbckService**
+
+Adds scheduleServerCrashProcedure to the HbckService.
+
+
+---
+
+* [HBASE-21325](https://issues.apache.org/jira/browse/HBASE-21325) | *Major* | **Force to terminate regionserver when abort hang in somewhere**
+
+Add two new config hbase.regionserver.abort.timeout and hbase.regionserver.abort.timeout.task. If regionserver abort timeout, it will schedule an abort timeout task to run. The default abort task is SystemExitWhenAbortTimeout, which will force to terminate region server when abort timeout. And you can config a special abort timeout task by hbase.regionserver.abort.timeout.task.
+
+
+---
+
+* [HBASE-21215](https://issues.apache.org/jira/browse/HBASE-21215) | *Major* | **Figure how to invoke hbck2; make it easy to find**
+
+Adds to bin/hbase means of invoking hbck2. Pass the new '-j' option on the 'hbck' command with a value of the full path to the HBCK2.jar.
+
+E.g:
+
+$ ./bin/hbase hbck -j ~/checkouts/hbase-operator-tools/hbase-hbck2/target/hbase-hbck2-1.0.0-SNAPSHOT.jar setTableState x ENABLED
+
+
+---
+
+* [HBASE-21372](https://issues.apache.org/jira/browse/HBASE-21372) | *Major* | **Set hbase.assignment.maximum.attempts to Long.MAX**
+
+Retry assigns 'forever' (or until an intervention such as a ServerCrashProcedure).
+
+Previous retry was a maximum of ten times but on failure, handling was an indeterminate.
+
+
+---
+
+* [HBASE-21338](https://issues.apache.org/jira/browse/HBASE-21338) | *Major* | **[balancer] If balancer is an ill-fit for cluster size, it gives little indication**
+
+The description claims the balancer not dynamically configurable but this is an error; it is http://hbase.apache.org/book.html#dyn\_config
+
+Also, if balancer is seen to be cutting out too soon, try setting "hbase.master.balancer.stochastic.runMaxSteps" to true.
+
+Adds cleaner logging around balancer start.
+
+
+---
+
+* [HBASE-21073](https://issues.apache.org/jira/browse/HBASE-21073) | *Major* | **"Maintenance mode" master**
+
+ Instead of being an ephemeral state set by hbck, maintenance mode is now
+ an explicit toggle set by either configuration property or environment
+ variable. In maintenance mode, master will host system tables and not
+ assign any user-space tables to RSs. This gives operators the ability to
+ affect repairs to meta table with fewer moving parts.
+
+
+---
+
+* [HBASE-21335](https://issues.apache.org/jira/browse/HBASE-21335) | *Critical* | **Change the default wait time of HBCK2 tool**
+
+Changed waitTime parameter to lockWait on bypass. Changed default waitTime from 0 -- i.e. wait for ever -- to 1ms so if lock is held, we'll go past it and if override enforce bypass.
+
+
+---
+
+* [HBASE-21291](https://issues.apache.org/jira/browse/HBASE-21291) | *Major* | **Add a test for bypassing stuck state-machine procedures**
+
+bypass will now throw an Exception if passed a lockWait \<= 0; i.e bypass will prevent an operator getting stuck on an entity lock waiting forever (lockWait == 0)
+
+
+---
+
+* [HBASE-21320](https://issues.apache.org/jira/browse/HBASE-21320) | *Major* | **[canary] Cleanup of usage and add commentary**
+
+Cleans up usage and docs around Canary. Does not change command-line args (though we should -- smile).
+
+
+---
+
+* [HBASE-21278](https://issues.apache.org/jira/browse/HBASE-21278) | *Critical* | **Do not rollback successful sub procedures when rolling back a procedure**
+
+For the sub procedures which are successfully finished, do not do rollback. This is a change in rollback behavior.
+
+State changes which are done by sub procedures should be handled by parent procedures when rolling back. For example, when rolling back a MergeTableProcedure, we will schedule new procedures to bring the offline regions online instead of rolling back the original procedures which off-lined the regions (in fact these procedures can not be rolled back...).
+
+
+---
+
+* [HBASE-21158](https://issues.apache.org/jira/browse/HBASE-21158) | *Critical* | **Empty qualifier cell should not be returned if it does not match QualifierFilter**
+
+<!-- markdown -->
+
+Scans that make use of `QualifierFilter` previously would erroneously return both columns with an empty qualifier along with those that matched. After this change that behavior has changed to only return those columns that match.
+
+
+---
+
+* [HBASE-21098](https://issues.apache.org/jira/browse/HBASE-21098) | *Major* | **Improve Snapshot Performance with Temporary Snapshot Directory when rootDir on S3**
+
+It is recommended to place the working directory on-cluster on HDFS as doing so has shown a strong performance increase due to data locality. It is important to note that the working directory should not overlap with any existing directories as the working directory will be cleaned out during the snapshot process. Beyond that, any well-named directory on HDFS should be sufficient.
+
+
+---
+
+* [HBASE-21185](https://issues.apache.org/jira/browse/HBASE-21185) | *Minor* | **WALPrettyPrinter: Additional useful info to be printed by wal printer tool, for debugability purposes**
+
+This adds two extra features to WALPrettyPrinter tool:
+
+1) Output for each cell combined size of cell descriptors, plus the cell value itself, in a given WAL edit. This is printed on the results as "cell total size sum:" info by default;
+
+2) An optional -g/--goto argument, that allows to seek straight to that specific WAL file position, then sequentially reading the WAL from that point towards its end;
+
+
+---
+
+* [HBASE-21287](https://issues.apache.org/jira/browse/HBASE-21287) | *Major* | **JVMClusterUtil Master initialization wait time not configurable**
+
+Local HBase cluster (as used by unit tests) wait times on startup and initialization can be configured via \`hbase.master.start.timeout.localHBaseCluster\` and \`hbase.master.init.timeout.localHBaseCluster\`
+
+
+---
+
+* [HBASE-21280](https://issues.apache.org/jira/browse/HBASE-21280) | *Trivial* | **Add anchors for each heading in UI**
+
+Adds anchors #tables, #tasks, etc.
+
+
+---
+
+* [HBASE-21232](https://issues.apache.org/jira/browse/HBASE-21232) | *Major* | **Show table state in Tables view on Master home page**
+
+Add table state column to the tables panel
+
+
+---
+
+* [HBASE-21223](https://issues.apache.org/jira/browse/HBASE-21223) | *Critical* | **[amv2] Remove abort\_procedure from shell**
+
+Removed the abort\_procedure command from shell -- dangerous -- and deprecated abortProcedure in Admin API.
+
+
+---
+
+* [HBASE-20636](https://issues.apache.org/jira/browse/HBASE-20636) | *Major* | **Introduce two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED**
+
+Add two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED
+1. ROWPREFIX\_FIXED\_LENGTH: specify the length of the prefix
+2. ROWPREFIX\_DELIMITED: specify the delimiter of the prefix
+Need to specify parameters for these two types of bloomfilter, otherwise the table will fail to create
+Example:
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_FIXED\_LENGTH', CONFIGURATION =\> {'RowPrefixBloomFilter.prefix\_length' =\> '10'}}
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_DELIMITED', CONFIGURATION =\> {'RowPrefixDelimitedBloomFilter.delimiter' =\> '#'}}
+
+
+---
+
+* [HBASE-21156](https://issues.apache.org/jira/browse/HBASE-21156) | *Critical* | **[hbck2] Queue an assign of hbase:meta and bulk assign/unassign**
+
+Adds 'raw' assigns/unassigns to the Hbck Service. Takes a list of encoded region names and bulk assigns/unassigns. Skirts Master 'state' check and does not invoke Coprocessors. For repair only.
+
+Here is what HBCK2 usage looks like now:
+
+{code}
+$ java -cp hbase-hbck2-1.0.0-SNAPSHOT.jar org.apache.hbase.HBCK2
+usage: HBCK2 \<OPTIONS\> COMMAND [\<ARGS\>]
+
+Options:
+ -d,--debug run with debug output
+ -h,--help output this help message
+ --hbase.zookeeper.peerport peerport of target hbase ensemble
+ --hbase.zookeeper.quorum ensemble of target hbase
+ --zookeeper.znode.parent parent znode of target hbase
+
+Commands:
+ setTableState \<TABLENAME\> \<STATE\>
+ Possible table states: ENABLED, DISABLED, DISABLING, ENABLING
+ To read current table state, in the hbase shell run:
+ hbase\> get 'hbase:meta', '\<TABLENAME\>', 'table:state'
+ A value of \\x08\\x00 == ENABLED, \\x08\\x01 == DISABLED, etc.
+ An example making table name 'user' ENABLED:
+ $ HBCK2 setTableState users ENABLED
+ Returns whatever the previous table state was.
+
+ assign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' assign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ e.g. 1588230740 is hard-coded encoding for hbase:meta region and
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 assign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created AssignProcedure or -1 if none.
+
+ unassign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' unassign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 unassign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created UnassignProcedure or -1 if none.
+{code}
+
+
+---
+
+* [HBASE-21021](https://issues.apache.org/jira/browse/HBASE-21021) | *Major* | **Result returned by Append operation should be ordered**
+
+This change ensures Append operations are assembled into the expected order.
+
+
+---
+
+* [HBASE-21171](https://issues.apache.org/jira/browse/HBASE-21171) | *Major* | **[amv2] Tool to parse a directory of MasterProcWALs standalone**
+
+Make it so can run the WAL parse and load system in isolation. Here is an example:
+
+{code}$ HBASE\_OPTS=" -XX:+UnlockDiagnosticVMOptions -XX:+UnlockCommercialFeatures -XX:+FlightRecorder -XX:+DebugNonSafepoints" ./bin/hbase org.apache.hadoop.hbase.procedure2.store.wal.WALProcedureStore ~/big\_set\_of\_masterprocwals/
+{code}
+
+
+---
+
+* [HBASE-21107](https://issues.apache.org/jira/browse/HBASE-21107) | *Minor* | **add a metrics for netty direct memory**
+
+Add a new nettyDirectMemoryUsage under server's ipc metrics to show direct memory usage for netty rpc server.
+
+
+---
+
+* [HBASE-21153](https://issues.apache.org/jira/browse/HBASE-21153) | *Major* | **Shaded client jars should always build in relevant phase to avoid confusion**
+
+Client facing artifacts are now built whenever Maven is run through the "package" goal. Previously, the client facing artifacts would create placeholder jars that skipped repackaging HBase and third-party dependencies unless the "release" profile was active.
+
+Build times may be noticeably longer depending on your build hardware. For example, the Jenkins worker nodes maintained by ASF Infra take ~14% longer to do a full packaging build. An example portability-focused personal laptop took ~25% longer.
+
+
+---
+
+* [HBASE-20942](https://issues.apache.org/jira/browse/HBASE-20942) | *Major* | **Improve RpcServer TRACE logging**
+
+Allows configuration of the length of RPC messages printed to the log at TRACE level via "hbase.ipc.trace.param.size" in RpcServer.
+
+
+---
+
+* [HBASE-20649](https://issues.apache.org/jira/browse/HBASE-20649) | *Minor* | **Validate HFiles do not have PREFIX\_TREE DataBlockEncoding**
+
+<!-- markdown -->
+Users who have previously made use of prefix tree encoding can now check that their existing HFiles no longer contain data that uses it with an additional preupgrade check command.
+
+```
+hbase pre-upgrade validate-hfile
+```
+
+Please see the "HFile Content validation" section of the ref guide's coverage of the pre-upgrade validator tool for usage details.
+
+
+---
+
+* [HBASE-20941](https://issues.apache.org/jira/browse/HBASE-20941) | *Major* | **Create and implement HbckService in master**
+
+Adds an HBCK Service and a first method to force-change-in-table-state for use by an HBCK client effecting 'repair' to a malfunctioning HBase.
+
+
+---
+
+* [HBASE-21071](https://issues.apache.org/jira/browse/HBASE-21071) | *Major* | **HBaseTestingUtility::startMiniCluster() to use builder pattern**
+
+Cleanup all the cluster start override combos in HBaseTestingUtility by adding a StartMiniClusterOption and Builder.
+
+
+---
+
+* [HBASE-21072](https://issues.apache.org/jira/browse/HBASE-21072) | *Major* | **Block out HBCK1 in hbase2**
+
+Fence out hbase-1.x hbck1 instances. Stop them making state changes on an hbase-2.x cluster; they could do damage. We do this by writing the hbck1 lock file into place on hbase-2.x Master start-up.
+
+To disable this new behavior, set hbase.write.hbck1.lock.file to false
+
+
+---
+
+* [HBASE-20881](https://issues.apache.org/jira/browse/HBASE-20881) | *Major* | **Introduce a region transition procedure to handle all the state transition for a region**
+
+Introduced a new TransitRegionStateProcedure to replace the old AssignProcedure/UnassignProcedure/MoveRegionProcedure. In the old code, MRP will not be attached to RegionStateNode, so it can not be interrupted by ServerCrashProcedure, which introduces lots of tricky code to deal with races, and also causes lots of other difficulties on how to prevent scheduling redundant or even conflict procedures for a region.
+
+And now TRSP is the only one procedure which can bring region online or offline. When you want to schedule one, you need to check whether there is already one attached to the RegionStateNode, under the lock of the RegionStateNode. If not just go ahead, and if there is one, then you should do something, for example, give up and fail directly, or tell the TRSP to give up(This is what SCP does). Since the check and attach are both under the lock of RSN, it will greatly reduce the possible r [...]
+
+
+---
+
+* [HBASE-21012](https://issues.apache.org/jira/browse/HBASE-21012) | *Critical* | **Revert the change of serializing TimeRangeTracker**
+
+HFiles generated by 2.0.0, 2.0.1, 2.1.0 are not forward compatible to 1.4.6-, 1.3.2.1-, 1.2.6.1-, and other inactive releases. Why HFile lose compatability is hbase in new versions (2.0.0, 2.0.1, 2.1.0) use protobuf to serialize/deserialize TimeRangeTracker (TRT) while old versions use DataInput/DataOutput. To solve this, We have to put HBASE-21012 to 2.x and put HBASE-21013 in 1.x. For more information, please check HBASE-21008.
+
+
+---
+
+* [HBASE-20965](https://issues.apache.org/jira/browse/HBASE-20965) | *Major* | **Separate region server report requests to new handlers**
+
+After HBASE-20965, we can use MasterFifoRpcScheduler in master to separate RegionServerReport requests to indenpedent handler. To use this feature, please set "hbase.master.rpc.scheduler.factory.class" to
+ "org.apache.hadoop.hbase.ipc.MasterFifoRpcScheduler". Use "hbase.master.server.report.handler.count" to set RegionServerReport handlers count, the default value is half of "hbase.regionserver.handler.count" value, but at least 1, and the other handlers count in master is "hbase.regionserver.handler.count" value minus RegionServerReport handlers count, but at least 1 too.
+
+
+---
+
+* [HBASE-20813](https://issues.apache.org/jira/browse/HBASE-20813) | *Minor* | **Remove RPC quotas when the associated table/Namespace is dropped off**
+
+In previous releases, when a Space Quota was configured on a table or namespace and that table or namespace was deleted, the Space Quota was also deleted. This change improves the implementation so that the same is also done for RPC Quotas.
+
+
+---
+
+* [HBASE-20986](https://issues.apache.org/jira/browse/HBASE-20986) | *Major* | **Separate the config of block size when we do log splitting and write Hlog**
+
+After HBASE-20986, we can set different value to block size of WAL and recovered edits. Both of their default value is 2 \* default HDFS blocksize. And hbase.regionserver.recoverededits.blocksize is for block size of recovered edits while hbase.regionserver.hlog.blocksize is for block size of WAL.
+
+
+---
+
+* [HBASE-20856](https://issues.apache.org/jira/browse/HBASE-20856) | *Minor* | **PITA having to set WAL provider in two places**
+
+With this change if a WAL's meta provider (hbase.wal.meta\_provider) is not explicitly set, it now defaults to whatever hbase.wal.provider is set to. Previous, the two settings operated independently, each with its own default.
+
+This change is operationally incompatible with previous HBase versions because the default WAL meta provider no longer defaults to AsyncFSWALProvider but to hbase.wal.provider.
+
+The thought is that this is more in line with an operator's expectation, that a change in hbase.wal.provider is sufficient to change how WALs are written, especially given hbase.wal.meta\_provider is an obscure configuration and that the very idea that meta regions would have their own wal provider would likely come as a surprise.
+
+
+---
+
+* [HBASE-20538](https://issues.apache.org/jira/browse/HBASE-20538) | *Critical* | **Upgrade our hadoop versions to 2.7.7 and 3.0.3**
+
+Update hadoop-two.version to 2.7.7 and hadoop-three.version to 3.0.3 due to a JDK issue which is solved by HADOOP-15473.
+
+
+---
+
+* [HBASE-20846](https://issues.apache.org/jira/browse/HBASE-20846) | *Major* | **Restore procedure locks when master restarts**
+
+1. Make hasLock method final, and add a locked field in Procedure to record whether we have the lock. We will set it to true in doAcquireLock and to false in doReleaseLock. The sub procedures do not need to manage it any more.
+
+2. Also added a locked field in the proto message. When storing, the field will be set according to the return value of hasLock. And when loading, there is a new field in Procedure called lockedWhenLoading. We will set it to true if the locked field in proto message is true.
+
+3. The reason why we can not set the locked field directly to true by calling doAcquireLock is that, during initialization, most procedures need to wait until master is initialized. So the solution here is that, we introduced a new method called waitInitialized in Procedure, and move the wait master initialized related code from acquireLock to this method. And we added a restoreLock method to Procedure, if lockedWhenLoading is true, we will call the acquireLock to get the lock, but do no [...]
+
+
+---
+
+* [HBASE-20672](https://issues.apache.org/jira/browse/HBASE-20672) | *Minor* | **New metrics ReadRequestRate and WriteRequestRate**
+
+Exposing 2 new metrics in HBase to provide ReadRequestRate and WriteRequestRate at region server level. These metrics give the rate of request handled by the region server and are reset after every monitoring interval.
+
+
+---
+
+* [HBASE-6028](https://issues.apache.org/jira/browse/HBASE-6028) | *Minor* | **Implement a cancel for in-progress compactions**
+
+Added a new command to the shell to switch on/off compactions called "compaction\_switch". Disabling compactions will interrupt any currently ongoing compactions. This setting will be lost on restart of the server. Added the configuration hbase.regionserver.compaction.enabled so user can enable/disable compactions via hbase-site.xml.
+
+
+---
+
+* [HBASE-20884](https://issues.apache.org/jira/browse/HBASE-20884) | *Major* | **Replace usage of our Base64 implementation with java.util.Base64**
+
+Class org.apache.hadoop.hbase.util.Base64 has been removed in it's entirety from HBase 2+. In HBase 1, unused methods have been removed from the class and the audience was changed from Public to Private. This class was originally intended as an internal utility class that could be used externally but thinking since changed; these classes should not have been advertised as public to end-users.
+
+This represents an incompatible change for users who relied on this implementation. An alternative implementation for affected clients is available at java.util.Base64 when using Java 8 or newer; be aware, it may encode/decode differently. For clients seeking to restore this specific implementation, it is available in the public domain for download at http://iharder.sourceforge.net/current/java/base64/
+
+
+---
+
+* [HBASE-20357](https://issues.apache.org/jira/browse/HBASE-20357) | *Major* | **AccessControlClient API Enhancement**
+
+This enhances the AccessControlClient APIs to retrieve the permissions based on namespace, table name, family and qualifier for specific user. AccessControlClient can also validate a user whether allowed to perform specified operations on a particular table.
+Following APIs have been added,
+1) getUserPermissions(Connection connection, String tableRegex, byte[] columnFamily, byte[] columnQualifier, String userName)
+ Scope of retrieving permission will be same as existing.
+2) hasPermission(onnection connection, String tableName, byte[] columnFamily, byte[] columnQualifier, String userName, Permission.Action... actions)
+ Scope of validating user privilege,
+ User can perform self check without any special privilege but ADMIN privilege will be required to perform check for other users.
+ For example, suppose there are two users "userA" & "userB" then there can be below scenarios,
+ a. When userA want to check whether userA have privilege to perform mentioned actions
+ userA don't need ADMIN privilege, as it's a self query.
+ b. When userA want to check whether userB have privilege to perform mentioned actions,
+ userA must have ADMIN or superuser privilege, as it's trying to query for other user.
+
+
+
+
+Scans that make use of `QualifierFilter` previously would erroneously return both columns with an empty qualifier along with those that matched. After this change that behavior has changed to only return those columns that match.
+
+
+---
+
+* [HBASE-21098](https://issues.apache.org/jira/browse/HBASE-21098) | *Major* | **Improve Snapshot Performance with Temporary Snapshot Directory when rootDir on S3**
+
+It is recommended to place the working directory on-cluster on HDFS as doing so has shown a strong performance increase due to data locality. It is important to note that the working directory should not overlap with any existing directories as the working directory will be cleaned out during the snapshot process. Beyond that, any well-named directory on HDFS should be sufficient.
+
+
+---
+
+* [HBASE-21185](https://issues.apache.org/jira/browse/HBASE-21185) | *Minor* | **WALPrettyPrinter: Additional useful info to be printed by wal printer tool, for debugability purposes**
+
+This adds two extra features to WALPrettyPrinter tool:
+
+1) Output for each cell combined size of cell descriptors, plus the cell value itself, in a given WAL edit. This is printed on the results as "cell total size sum:" info by default;
+
+2) An optional -g/--goto argument, that allows to seek straight to that specific WAL file position, then sequentially reading the WAL from that point towards its end;
+
+
+---
+
+* [HBASE-21287](https://issues.apache.org/jira/browse/HBASE-21287) | *Major* | **JVMClusterUtil Master initialization wait time not configurable**
+
+Local HBase cluster (as used by unit tests) wait times on startup and initialization can be configured via \`hbase.master.start.timeout.localHBaseCluster\` and \`hbase.master.init.timeout.localHBaseCluster\`
+
+
+---
+
+* [HBASE-21280](https://issues.apache.org/jira/browse/HBASE-21280) | *Trivial* | **Add anchors for each heading in UI**
+
+Adds anchors #tables, #tasks, etc.
+
+
+---
+
+* [HBASE-21232](https://issues.apache.org/jira/browse/HBASE-21232) | *Major* | **Show table state in Tables view on Master home page**
+
+Add table state column to the tables panel
+
+
+---
+
+* [HBASE-21223](https://issues.apache.org/jira/browse/HBASE-21223) | *Critical* | **[amv2] Remove abort\_procedure from shell**
+
+Removed the abort\_procedure command from shell -- dangerous -- and deprecated abortProcedure in Admin API.
+
+
+---
+
+* [HBASE-20636](https://issues.apache.org/jira/browse/HBASE-20636) | *Major* | **Introduce two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED**
+
+Add two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED
+1. ROWPREFIX\_FIXED\_LENGTH: specify the length of the prefix
+2. ROWPREFIX\_DELIMITED: specify the delimiter of the prefix
+Need to specify parameters for these two types of bloomfilter, otherwise the table will fail to create
+Example:
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_FIXED\_LENGTH', CONFIGURATION =\> {'RowPrefixBloomFilter.prefix\_length' =\> '10'}}
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_DELIMITED', CONFIGURATION =\> {'RowPrefixDelimitedBloomFilter.delimiter' =\> '#'}}
+
+
+---
+
+* [HBASE-21156](https://issues.apache.org/jira/browse/HBASE-21156) | *Critical* | **[hbck2] Queue an assign of hbase:meta and bulk assign/unassign**
+
+Adds 'raw' assigns/unassigns to the Hbck Service. Takes a list of encoded region names and bulk assigns/unassigns. Skirts Master 'state' check and does not invoke Coprocessors. For repair only.
+
+Here is what HBCK2 usage looks like now:
+
+{code}
+$ java -cp hbase-hbck2-1.0.0-SNAPSHOT.jar org.apache.hbase.HBCK2
+usage: HBCK2 \<OPTIONS\> COMMAND [\<ARGS\>]
+
+Options:
+ -d,--debug run with debug output
+ -h,--help output this help message
+ --hbase.zookeeper.peerport peerport of target hbase ensemble
+ --hbase.zookeeper.quorum ensemble of target hbase
+ --zookeeper.znode.parent parent znode of target hbase
+
+Commands:
+ setTableState \<TABLENAME\> \<STATE\>
+ Possible table states: ENABLED, DISABLED, DISABLING, ENABLING
+ To read current table state, in the hbase shell run:
+ hbase\> get 'hbase:meta', '\<TABLENAME\>', 'table:state'
+ A value of \\x08\\x00 == ENABLED, \\x08\\x01 == DISABLED, etc.
+ An example making table name 'user' ENABLED:
+ $ HBCK2 setTableState users ENABLED
+ Returns whatever the previous table state was.
+
+ assign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' assign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ e.g. 1588230740 is hard-coded encoding for hbase:meta region and
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 assign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created AssignProcedure or -1 if none.
+
+ unassign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' unassign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 unassign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created UnassignProcedure or -1 if none.
+{code}
+
+
+---
+
+* [HBASE-21021](https://issues.apache.org/jira/browse/HBASE-21021) | *Major* | **Result returned by Append operation should be ordered**
+
+This change ensures Append operations are assembled into the expected order.
+
+
+---
+
+* [HBASE-21171](https://issues.apache.org/jira/browse/HBASE-21171) | *Major* | **[amv2] Tool to parse a directory of MasterProcWALs standalone**
+
+Make it so can run the WAL parse and load system in isolation. Here is an example:
+
+{code}$ HBASE\_OPTS=" -XX:+UnlockDiagnosticVMOptions -XX:+UnlockCommercialFeatures -XX:+FlightRecorder -XX:+DebugNonSafepoints" ./bin/hbase org.apache.hadoop.hbase.procedure2.store.wal.WALProcedureStore ~/big\_set\_of\_masterprocwals/
+{code}
+
+
+---
+
+* [HBASE-21107](https://issues.apache.org/jira/browse/HBASE-21107) | *Minor* | **add a metrics for netty direct memory**
+
+Add a new nettyDirectMemoryUsage under server's ipc metrics to show direct memory usage for netty rpc server.
+
+
+---
+
+* [HBASE-21153](https://issues.apache.org/jira/browse/HBASE-21153) | *Major* | **Shaded client jars should always build in relevant phase to avoid confusion**
+
+Client facing artifacts are now built whenever Maven is run through the "package" goal. Previously, the client facing artifacts would create placeholder jars that skipped repackaging HBase and third-party dependencies unless the "release" profile was active.
+
+Build times may be noticeably longer depending on your build hardware. For example, the Jenkins worker nodes maintained by ASF Infra take ~14% longer to do a full packaging build. An example portability-focused personal laptop took ~25% longer.
+
+
+---
+
+* [HBASE-20942](https://issues.apache.org/jira/browse/HBASE-20942) | *Major* | **Improve RpcServer TRACE logging**
+
+Allows configuration of the length of RPC messages printed to the log at TRACE level via "hbase.ipc.trace.param.size" in RpcServer.
+
+
+---
+
+* [HBASE-20649](https://issues.apache.org/jira/browse/HBASE-20649) | *Minor* | **Validate HFiles do not have PREFIX\_TREE DataBlockEncoding**
+
+<!-- markdown -->
+# HBASE 2.2.0 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | *Major* | **Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements**
+
+Moving IA.Public class LossyCounting to IA.Private.
+
+
+---
+
+* [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | *Major* | **Update hadoop check versions for hadoop3 in hbase-personality**
+
+Add hadoop 3.0.3, 3.1.1 3.1.2 in our hadoop check jobs.
+
+
+---
+
+* [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | *Major* | **Dump replication queue should show list of wal files ordered chronologically**
+
+The DumpReplicationQueues tool will now list replication queues sorted in chronological order.
+
+
+---
+
+* [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | *Minor* | **Formatting issues in administration section of book**
+
+Fixes a formatting issue in the administration section of the book, where listing indentation were a little bit off.
+
+
+---
+
+* [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | *Major* | **Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks**
+
+Now the default hadoop-two.version has been changed to 2.8.5, and all hadoop versions before 2.8.2(exclude) will not be supported any more.
+
+
+---
+
+* [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | *Trivial* | **Remove extra/useless +**
+
+Removed extra + in HRegion, HStore and LoadIncrementalHFiles for branch-2 and HRegion and HStore for branch-1.
+
+
+---
+
+* [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | *Trivial* | **Fix completebulkload usage instructions**
+
+Added completebulkload short name for BulkLoadHFilesTool to bin/hbase.
+
+
+---
+
+* [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | *Major* | **Upgrade com.yammer.metrics dependency**
+
+Updated metrics core from 3.2.1 to 3.2.6.
+
+
+---
+
+* [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | *Minor* | **Change rubocop configuration for method length**
+
+The rubocop definition for the maximum method length was set to 75.
+
+
+---
+
+* [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | *Minor* | **Fix Markdown for "Voting on Release Candidates" in book**
+
+Fixes the formatting of the "Voting on Release Candidates" to actually show the quote and code formatting of the RAT check.
+
+
+---
+
+* [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | *Minor* | **Change rubocop config for max line length of 100**
+
+The rubocop configuration in the hbase-shell module now allows a line length with 100 characters, instead of 80 as before. For everything before 2.1.5 this change introduces rubocop itself.
+
+
+---
+
+* [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | *Minor* | **Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS**
+
+This change allows the system and superusers to initiate compactions, even when a space quota violation policy disallows compactions from happening. The original intent behind disallowing of compactions was to prevent end-user compactions from creating undue I/O load, not disallowing \*any\* compaction in the system.
+
+
+---
+
+* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
+
+Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
+
+
+---
+
+* [HBASE-22155](https://issues.apache.org/jira/browse/HBASE-22155) | *Major* | **Move 2.2.0 on to hbase-thirdparty-2.2.0**
+
+ Updates libs used internally by hbase via hbase-thirdparty as follows:
+
+ gson 2.8.1 -\\\> 2.8.5
+ guava 22.0 -\\\> 27.1-jre
+ pb 3.5.1 -\\\> 3.7.0
+ netty 4.1.17 -\\\> 4.1.34
+ commons-collections4 4.1 -\\\> 4.3
+
+
+---
+
+* [HBASE-22178](https://issues.apache.org/jira/browse/HBASE-22178) | *Major* | **Introduce a createTableAsync with TableDescriptor method in Admin**
+
+Introduced
+
+Future\<Void\> createTableAsync(TableDescriptor);
+
+
+---
+
+* [HBASE-22108](https://issues.apache.org/jira/browse/HBASE-22108) | *Major* | **Avoid passing null in Admin methods**
+
+Introduced these methods:
+void move(byte[]);
+void move(byte[], ServerName);
+Future\<Void\> splitRegionAsync(byte[]);
+
+These methods are deprecated:
+void move(byte[], byte[])
+
+
+---
+
+* [HBASE-22152](https://issues.apache.org/jira/browse/HBASE-22152) | *Major* | **Create a jenkins file for yetus to processing GitHub PR**
+
+Add a new jenkins file for running pre commit check for GitHub PR.
+
+
+---
+
+* [HBASE-22007](https://issues.apache.org/jira/browse/HBASE-22007) | *Major* | **Add restoreSnapshot and cloneSnapshot with acl methods in AsyncAdmin**
+
+Add cloneSnapshot/restoreSnapshot with acl methods in AsyncAdmin.
+
+
+---
+
+* [HBASE-22123](https://issues.apache.org/jira/browse/HBASE-22123) | *Minor* | **REST gateway reports Insufficient permissions exceptions as 404 Not Found**
+
+When insufficient permissions, you now get:
+
+HTTP/1.1 403 Forbidden
+
+on the HTTP side, and in the message
+
+Forbidden
+org.apache.hadoop.hbase.security.AccessDeniedException: org.apache.hadoop.hbase.security.AccessDeniedException: Insufficient permissions for user ‘myuser',action: get, tableName:mytable, family:cf.
+at org.apache.ranger.authorization.hbase.RangerAuthorizationCoprocessor.authorizeAccess(RangerAuthorizationCoprocessor.java:547)
+and the rest of the ADE stack
+
+
+---
+
+* [HBASE-22100](https://issues.apache.org/jira/browse/HBASE-22100) | *Minor* | **False positive for error prone warnings in pre commit job**
+
+Now we will sort the javac WARNING/ERROR before generating diff in pre-commit so we can get a stable output for the error prone. The downside is that we just sort the output lexicographically so the line number will also be sorted lexicographically, which is a bit strange to human.
+
+
+---
+
+* [HBASE-22057](https://issues.apache.org/jira/browse/HBASE-22057) | *Major* | **Impose upper-bound on size of ZK ops sent in a single multi()**
+
+Exposes a new configuration property "zookeeper.multi.max.size" which dictates the maximum size of deletes that HBase will make to ZooKeeper in a single RPC. This property defaults to 1MB, which should fall beneath the default ZooKeeper limit of 2MB, controlled by "jute.maxbuffer".
+
+
+---
+
+* [HBASE-22052](https://issues.apache.org/jira/browse/HBASE-22052) | *Major* | **pom cleaning; filter out jersey-core in hadoop2 to match hadoop3 and remove redunant version specifications**
+
+<!-- markdown -->
+Fixed awkward dependency issue that prevented site building.
+
+#### note specific to HBase 2.1.4
+HBase 2.1.4 shipped with an early version of this fix that incorrectly altered the libraries included in our binary assembly for using Apache Hadoop 2.7 (the current build default Hadoop version for 2.1.z). For folks running out of the box against a Hadoop 2.7 cluster (or folks who skip the installation step of [replacing the bundled Hadoop libraries](http://hbase.apache.org/book.html#hadoop)) this will result in a failure at Region Server startup due to a missing class definition. e.g.:
+```
+2019-03-27 09:02:05,779 ERROR [main] regionserver.HRegionServer: Failed construction RegionServer
+java.lang.NoClassDefFoundError: org/apache/htrace/SamplerBuilder
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:644)
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:628)
+ at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
+ at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)
+ at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:93)
+ at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2701)
+ at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2683)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:372)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:171)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:356)
+ at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getRootDir(CommonFSUtils.java:362)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.isValidWALRootDir(CommonFSUtils.java:411)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getWALRootDir(CommonFSUtils.java:387)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.initializeFileSystem(HRegionServer.java:704)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.<init>(HRegionServer.java:613)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
+ at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
+ at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.constructRegionServer(HRegionServer.java:3029)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.start(HRegionServerCommandLine.java:63)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.run(HRegionServerCommandLine.java:87)
+ at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
+ at org.apache.hadoop.hbase.util.ServerCommandLine.doMain(ServerCommandLine.java:149)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.main(HRegionServer.java:3047)
+Caused by: java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
+ at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
+ at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
+ ... 26 more
+
+```
+
+Workaround via any _one_ of the following:
+* If you are running against a Hadoop cluster that is 2.8+, ensure you replace the Hadoop libaries in the default binary assembly with those for your version.
+* If you are running against a Hadoop cluster that is 2.8+, build the binary assembly from the source release while specifying your Hadoop version.
+* If you are running against a Hadoop cluster that is a supported 2.7 release, ensure the `hadoop` executable is in the `PATH` seen at Region Server startup and that you are not using the `HBASE_DISABLE_HADOOP_CLASSPATH_LOOKUP` bypass.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers via the HBASE_CLASSPATH environment variable.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers by copying it into the directory `${HBASE_HOME}/lib/client-facing-thirdparty/`.
+
+
+---
+
+* [HBASE-22065](https://issues.apache.org/jira/browse/HBASE-22065) | *Major* | **Add listTableDescriptors(List\<TableName\>) method in AsyncAdmin**
+
+Add a listTableDescriptors(List\<TableName\>) method in the AsyncAdmin interface, to align with the Admin interface.
+
+
+---
+
+* [HBASE-22040](https://issues.apache.org/jira/browse/HBASE-22040) | *Major* | **Add mergeRegionsAsync with a List of region names method in AsyncAdmin**
+
+Add a mergeRegionsAsync(byte[][], boolean) method in the AsyncAdmin interface.
+
+Instead of using assert, now we will throw IllegalArgumentException when you want to merge less than 2 regions at client side. And also, at master side, instead of using assert, now we will throw DoNotRetryIOException if you want merge more than 2 regions, since we only support merging two regions at once for now.
+
+
+---
+
+* [HBASE-22039](https://issues.apache.org/jira/browse/HBASE-22039) | *Major* | **Should add the synchronous parameter for the XXXSwitch method in AsyncAdmin**
+
+Add drainXXX parameter for balancerSwitch/splitSwitch/mergeSwitch methods in the AsyncAdmin interface, which has the same meaning with the synchronous parameter for these methods in the Admin interface.
+
+
+---
+
+* [HBASE-21810](https://issues.apache.org/jira/browse/HBASE-21810) | *Major* | **bulkload support set hfile compression on client**
+
+bulkload (HFileOutputFormat2) support config the compression on client ,you can set the job configuration "hbase.mapreduce.hfileoutputformat.compression" override the auto-detection of the target table's compression
+
+
+---
+
+* [HBASE-22000](https://issues.apache.org/jira/browse/HBASE-22000) | *Major* | **Deprecated isTableAvailable with splitKeys**
+
+Deprecated AsyncTable.isTableAvailable(TableName, byte[][]).
+
+
+---
+
+* [HBASE-21871](https://issues.apache.org/jira/browse/HBASE-21871) | *Major* | **Support to specify a peer table name in VerifyReplication tool**
+
+After HBASE-21871, we can specify a peer table name with --peerTableName in VerifyReplication tool like the following:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable 5 TestTable
+
+In addition, we can compare any 2 tables in any remote clusters with specifying both peerId and --peerTableName.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable zk1,zk2,zk3:2181/hbase TestTable
+
+
+---
+
+* [HBASE-15728](https://issues.apache.org/jira/browse/HBASE-15728) | *Major* | **Add remaining per-table region / store / flush / compaction related metrics**
+
+Adds below flush, split, and compaction metrics
+
+ + // split related metrics
+ + private MutableFastCounter splitRequest;
+ + private MutableFastCounter splitSuccess;
+ + private MetricHistogram splitTimeHisto;
+ +
+ + // flush related metrics
+ + private MetricHistogram flushTimeHisto;
+ + private MetricHistogram flushMemstoreSizeHisto;
+ + private MetricHistogram flushOutputSizeHisto;
+ + private MutableFastCounter flushedMemstoreBytes;
+ + private MutableFastCounter flushedOutputBytes;
+ +
+ + // compaction related metrics
+ + private MetricHistogram compactionTimeHisto;
+ + private MetricHistogram compactionInputFileCountHisto;
+ + private MetricHistogram compactionInputSizeHisto;
+ + private MetricHistogram compactionOutputFileCountHisto;
+ + private MetricHistogram compactionOutputSizeHisto;
+ + private MutableFastCounter compactedInputBytes;
+ + private MutableFastCounter compactedOutputBytes;
+ +
+ + private MetricHistogram majorCompactionTimeHisto;
+ + private MetricHistogram majorCompactionInputFileCountHisto;
+ + private MetricHistogram majorCompactionInputSizeHisto;
+ + private MetricHistogram majorCompactionOutputFileCountHisto;
+ + private MetricHistogram majorCompactionOutputSizeHisto;
+ + private MutableFastCounter majorCompactedInputBytes;
+ + private MutableFastCounter majorCompactedOutputBytes;
+
+
+---
+
+* [HBASE-20886](https://issues.apache.org/jira/browse/HBASE-20886) | *Critical* | **[Auth] Support keytab login in hbase client**
+
+From 2.2.0, hbase supports client login via keytab. To use this feature, client should specify \`hbase.client.keytab.file\` and \`hbase.client.keytab.principal\` in hbase-site.xml, then the connection will contain the needed credentials which be renewed periodically to communicate with kerberized hbase cluster.
+
+
+---
+
+* [HBASE-21410](https://issues.apache.org/jira/browse/HBASE-21410) | *Major* | **A helper page that help find all problematic regions and procedures**
+
+After HBASE-21410, we add a helper page to Master UI. This helper page is mainly to help HBase operator quickly found all regions and pids that are get stuck.
+There are 2 entries to get in this page.
+One is showing in the Regions in Transition section, it made "num region(s) in transition" a link that you can click and check all regions in transition and their related procedure IDs.
+The other one is showing in the table details section, it made the number of CLOSING or OPENING regions a link, which you can click and check regions and related procedure IDs of CLOSING or OPENING regions of a certain table.
+In this helper page, not only you can see all regions and related procedures, there are 2 buttons at the top which will show these regions or procedure IDs in text format. This is mainly aim to help operator to easily copy and paste all problematic procedure IDs and encoded region names to HBCK2's command line, by which we HBase operator can bypass these procedures or assign these regions.
+
+
+---
+
+* [HBASE-21588](https://issues.apache.org/jira/browse/HBASE-21588) | *Major* | **Procedure v2 wal splitting implementation**
+
+After HBASE-21588, we introduce a new way to do WAL splitting coordination by procedure framework. This can simplify the process of WAL splitting and no need to connect zookeeper any more.
+During ServerCrashProcedure, it will create a SplitWALProcedure for each WAL that need to split. Then each SplitWALProcedure will spawn a SplitWALRemoteProcedure to send the request to regionserver.
+At the RegionServer side, whole process is handled by SplitWALCallable. It split the WAL and return the result to master.
+According to my test, this patch has a better performance as the number of WALs that need to split increase. And it can relieve the pressure on zookeeper.
+
+
+---
+
+* [HBASE-20734](https://issues.apache.org/jira/browse/HBASE-20734) | *Major* | **Colocate recovered edits directory with hbase.wal.dir**
+
+Previously the recovered.edits directory was under the root directory. This JIRA moves the recovered.edits directory to be under the hbase.wal.dir if set. It also adds a check for any recovered.edits found under the root directory for backwards compatibility. This gives improvements when a faster media(like SSD) or more local FileSystem is used for the hbase.wal.dir than the root dir.
+
+
+---
+
+* [HBASE-20401](https://issues.apache.org/jira/browse/HBASE-20401) | *Minor* | **Make \`MAX\_WAIT\` and \`waitIfNotFinished\` in CleanerContext configurable**
+
+When oldwals (and hfile) cleaner cleans stale wals (and hfiles), it will periodically check and wait the clean results from filesystem, the total wait time will be no more than a max time.
+
+The periodically wait and check configurations are hbase.oldwals.cleaner.thread.check.interval.msec (default is 500 ms) and hbase.regionserver.hfilecleaner.thread.check.interval.msec (default is 1000 ms).
+
+Meanwhile, The max time configurations are hbase.oldwals.cleaner.thread.timeout.msec and hbase.regionserver.hfilecleaner.thread.timeout.msec, they are set to 60 seconds by default.
+
+All support dynamic configuration.
+
+e.g. in the oldwals cleaning scenario, one may consider tuning hbase.oldwals.cleaner.thread.timeout.msec and hbase.oldwals.cleaner.thread.check.interval.msec
+
+1. While deleting a oldwal never complete (strange but possible), then delete file task needs to wait for a max of 60 seconds. Here, 60 seconds might be too long, or the opposite way is to increase more than 60 seconds in the use cases of slow file delete.
+2. The check and wait of a file delete is set to default in the period of 500 milliseconds, one might want to tune this checking period to a short interval to check more frequently or to a longer interval to avoid checking too often to manage their delete file task checking period (the longer interval may be use to avoid checking too fast while using a high latency storage).
+
+
+---
+
+* [HBASE-21481](https://issues.apache.org/jira/browse/HBASE-21481) | *Major* | **[acl] Superuser's permissions should not be granted or revoked by any non-su global admin**
+
+HBASE-21481 improves the quality of access control, by strengthening the protection of super users's privileges.
+
+
+---
+
+* [HBASE-21082](https://issues.apache.org/jira/browse/HBASE-21082) | *Critical* | **Reimplement assign/unassign related procedure metrics**
+
+Now we have four types of RIT procedure metrics, assign, unassign, move, reopen. The meaning of assign/unassign is changed, as we will not increase the unassign metric and then the assign metric when moving a region.
+Also introduced two new procedure metrics, open and close, which are used to track the open/close region calls to region server. We may send open/close multiple times to finish a RIT since we may retry multiple times.
+
+
+---
+
+* [HBASE-20724](https://issues.apache.org/jira/browse/HBASE-20724) | *Critical* | **Sometimes some compacted storefiles are still opened after region failover**
+
+Problem: This is an old problem since HBASE-2231. The compaction event marker was only writed to WAL. But after flush, the WAL may be archived, which means an useful compaction event marker be deleted, too. So the compacted store files cannot be archived when region open and replay WAL.
+
+Solution: After this jira, the compaction event tracker will be writed to HFile. When region open and load store files, read the compaction evnet tracker from HFile and archive the compacted store files which still exist.
+
+
+---
+
+* [HBASE-21820](https://issues.apache.org/jira/browse/HBASE-21820) | *Major* | **Implement CLUSTER quota scope**
+
+HBase contains two quota scopes: MACHINE and CLUSTER. Before this patch, set quota operations did not expose scope option to client api and use MACHINE as default, CLUSTER scope can not be set and used.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+
+This issue implements CLUSTER scope in a simple way: For user, namespace, user over namespace quota, use [ClusterLimit / RSNum] as machine limit. For table and user over table quota, use [ClusterLimit / TotalTableRegionNum \* MachineTableRegionNum] as machine limit.
+After this patch, user can set CLUSTER scope quota, but MACHINE is still default if user ignore scope.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> MACHINE
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> CLUSTER
+
+
+---
+
+* [HBASE-21057](https://issues.apache.org/jira/browse/HBASE-21057) | *Minor* | **upgrade to latest spotbugs**
+
+Change spotbugs version to 3.1.11.
+
+
+---
+
+* [HBASE-21922](https://issues.apache.org/jira/browse/HBASE-21922) | *Major* | **BloomContext#sanityCheck may failed when use ROWPREFIX\_DELIMITED bloom filter**
+
+Remove bloom filter type ROWPREFIX\_DELIMITED. May add it back when find a better solution.
+
+
+---
+
+* [HBASE-21783](https://issues.apache.org/jira/browse/HBASE-21783) | *Major* | **Support exceed user/table/ns throttle quota if region server has available quota**
+
+Support enable or disable exceed throttle quota. Exceed throttle quota means, user can over consume user/namespace/table quota if region server has additional available quota because other users don't consume at the same time.
+Use the following shell commands to enable/disable exceed throttle quota: enable\_exceed\_throttle\_quota
+disable\_exceed\_throttle\_quota
+There are two limits when enable exceed throttle quota:
+1. Must set at least one read and one write region server throttle quota;
+2. All region server throttle quotas must be in seconds time unit. Because once previous requests exceed their quota and consume region server quota, quota in other time units may be refilled in a long time, this may affect later requests.
+
+
+---
+
+* [HBASE-20587](https://issues.apache.org/jira/browse/HBASE-20587) | *Major* | **Replace Jackson with shaded thirdparty gson**
+
+Remove jackson dependencies from most hbase modules except hbase-rest, use shaded gson instead. The output json will be a bit different since jackson can use getter/setter, but gson will always use the fields.
+
+
+---
+
+* [HBASE-21928](https://issues.apache.org/jira/browse/HBASE-21928) | *Major* | **Deprecated HConstants.META\_QOS**
+
+Mark HConstants.META\_QOS as deprecated. It is for internal use only, which is the highest priority. You should not try to set a priority greater than or equal to this value, although it is no harm but also useless.
+
+
+---
+
+* [HBASE-17942](https://issues.apache.org/jira/browse/HBASE-17942) | *Major* | **Disable region splits and merges per table**
+
+This patch adds the ability to disable split and/or merge for a table (By default, split and merge are enabled for a table).
+
+
+---
+
+* [HBASE-21636](https://issues.apache.org/jira/browse/HBASE-21636) | *Major* | **Enhance the shell scan command to support missing scanner specifications like ReadType, IsolationLevel etc.**
+
+Allows shell to set Scan options previously not exposed. See additions as part of the scan help by typing following hbase shell:
+
+hbase\> help 'scan'
+
+
+---
+
+* [HBASE-21201](https://issues.apache.org/jira/browse/HBASE-21201) | *Major* | **Support to run VerifyReplication MR tool without peerid**
+
+We can specify peerQuorumAddress instead of peerId in VerifyReplication tool. So it no longer requires peerId to be setup when using this tool.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication zk1,zk2,zk3:2181/hbase testTable
+
+
+---
+
+* [HBASE-21838](https://issues.apache.org/jira/browse/HBASE-21838) | *Major* | **Create a special ReplicationEndpoint just for verifying the WAL entries are fine**
+
+Introduce a VerifyWALEntriesReplicationEndpoint which replicates nothing but only verifies if all the cells are valid.
+It can be used to capture bugs for writing WAL, as most times we will not read the WALs again after writing it if there are no region server crashes.
+
+
+---
+
+* [HBASE-21727](https://issues.apache.org/jira/browse/HBASE-21727) | *Minor* | **Simplify documentation around client timeout**
+
+Deprecated HBaseConfiguration#getInt(Configuration, String, String, int) method and removed it from 3.0.0 version.
+
+
+---
+
+* [HBASE-21764](https://issues.apache.org/jira/browse/HBASE-21764) | *Major* | **Size of in-memory compaction thread pool should be configurable**
+
+Introduced an new config key in this issue: hbase.regionserver.inmemory.compaction.pool.size. the default value would be 10. you can configure this to set the pool size of in-memory compaction pool. Note that all memstores in one region server will share the same pool, so if you have many regions in one region server, you need to set this larger to compact faster for better read performance.
+
+
+---
+
+* [HBASE-21684](https://issues.apache.org/jira/browse/HBASE-21684) | *Major* | **Throw DNRIOE when connection or rpc client is closed**
+
+Make StoppedRpcClientException extend DoNotRetryIOException.
+
+
+---
+
+* [HBASE-21739](https://issues.apache.org/jira/browse/HBASE-21739) | *Major* | **Move grant/revoke from regionserver to master**
+
+To implement user permission control in Precedure V2, move grant and revoke method from AccessController to master firstly.
+Mark AccessController#grant and AccessController#revoke as deprecated and please use Admin#grant and Admin#revoke instead.
+
+
+---
+
+* [HBASE-21791](https://issues.apache.org/jira/browse/HBASE-21791) | *Blocker* | **Upgrade thrift dependency to 0.12.0**
+
+IMPORTANT: Due to security issues, all users who use hbase thrift should avoid using releases which do not have this fix.
+
+The effect releases are:
+2.1.x: 2.1.2 and below
+2.0.x: 2.0.4 and below
+1.x: 1.4.x and below
+
+If you are using the effect releases above, please consider upgrading to a newer release ASAP.
+
+
+---
+
+* [HBASE-21792](https://issues.apache.org/jira/browse/HBASE-21792) | *Major* | **Mark HTableMultiplexer as deprecated and remove it in 3.0.0**
+
+HTableMultiplexer exposes the implementation class, and it is incomplete, so we mark it as deprecated and remove it in 3.0.0 release.
+
+There is no direct replacement for HTableMultiplexer, please use BufferedMutator if you want to batch mutations to a table.
+
+
+---
+
+* [HBASE-21782](https://issues.apache.org/jira/browse/HBASE-21782) | *Major* | **LoadIncrementalHFiles should not be IA.Public**
+
+Introduce a BulkLoadHFiles interface which is marked as IA.Public, for doing bulk load programmatically.
+Introduce a BulkLoadHFilesTool which extends BulkLoadHFiles, and is marked as IA.LimitedPrivate(TOOLS), for using from command line.
+The old LoadIncrementalHFiles is deprecated and will be removed in 3.0.0.
+
+
+---
+
+* [HBASE-21762](https://issues.apache.org/jira/browse/HBASE-21762) | *Major* | **Move some methods in ClusterConnection to Connection**
+
+Move the two getHbck method from ClusterConnection to Connection, and mark the methods as IA.LimitedPrivate(HBCK), as ClusterConnection is IA.Private and should not be depended by HBCK2.
+
+Add a clearRegionLocationCache method in Connection to clear the region location cache for all the tables. As in RegionLocator, most of the methods have a 'reload' parameter, which implicitly tells user that we have a region location cache, so adding a method to clear the cache is fine.
+
+
+---
+
+* [HBASE-21713](https://issues.apache.org/jira/browse/HBASE-21713) | *Major* | **Support set region server throttle quota**
+
+Support set region server rpc throttle quota which represents the read/write ability of region servers and throttles when region server's total requests exceeding the limit.
+
+Use the following shell command to set RS quota:
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', THROTTLE\_TYPE =\> WRITE, LIMIT =\> '20000req/sec'
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', LIMIT =\> NONE
+"all" represents the throttle quota of all region servers and setting specified region server quota isn't supported currently.
+
+
+---
+
+* [HBASE-21689](https://issues.apache.org/jira/browse/HBASE-21689) | *Minor* | **Make table/namespace specific current quota info available in shell(describe\_namespace & describe)**
+
+In shell commands "describe\_namespace" and "describe", which are used to see the descriptors of the namespaces and tables respectively, quotas set on that particular namespace/table will also be printed along.
+
+
+---
+
+* [HBASE-17370](https://issues.apache.org/jira/browse/HBASE-17370) | *Major* | **Fix or provide shell scripts to drain and decommission region server**
+
+Adds shell support for the following:
+- List decommissioned/draining region servers
+- Decommission a list of region servers, optionally offload corresponding regions
+- Recommission a region server, optionally load a list of passed regions
+
+
+---
+
+* [HBASE-21734](https://issues.apache.org/jira/browse/HBASE-21734) | *Major* | **Some optimization in FilterListWithOR**
+
+After HBASE-21620, the filterListWithOR has been a bit slow because we need to merge each sub-filter's RC , while before HBASE-21620, we will skip many RC merging, but the logic was wrong. So here we choose another way to optimaze the performance: removing the KeyValueUtil#toNewKeyCell.
+Anoop Sam John suggested that the KeyValueUtil#toNewKeyCell can save some GC before because if we copy key part of cell into a single byte[], then the block the cell refering won't be refered by the filter list any more, the upper layer can GC the data block quickly. while after HBASE-21620, we will update the prevCellList for every encountered cell now, so the lifecycle of cell in prevCellList for FilterList will be quite shorter. so just use the cell ref for saving cpu.
+BTW, we removed all the arrays streams usage in filter list, because it's also quite time-consuming in our test.
+
+
+---
+
+* [HBASE-21738](https://issues.apache.org/jira/browse/HBASE-21738) | *Critical* | **Remove all the CSLM#size operation in our memstore because it's an quite time consuming.**
+
+We found the memstore snapshotting would cost much time because of calling the time-consuming ConcurrentSkipListMap#Size, it would make the p999 latency spike happen. So in this issue, we remove all ConcurrentSkipListMap#size in memstore by counting the cellsCount in MemstoreSizeing. As the issue described, the p999 latency spike was mitigated.
+
+
+---
+
+* [HBASE-21034](https://issues.apache.org/jira/browse/HBASE-21034) | *Major* | **Add new throttle type: read/write capacity unit**
+
+Provides a new throttle type: capacity unit. One read/write/request capacity unit represents that read/write/read+write up to 1K data. If data size is more than 1K, then consume additional capacity units.
+
+Use shell command to set capacity unit(CU):
+set\_quota TYPE =\> THROTTLE, THROTTLE\_TYPE =\> WRITE, USER =\> 'u1', LIMIT =\> '10CU/sec'
+
+Use the "hbase.quota.read.capacity.unit" property to set the data size of one read capacity unit in bytes, the default value is 1K. Use the "hbase.quota.write.capacity.unit" property to set the data size of one write capacity unit in bytes, the default value is 1K.
+
+
+---
+
+* [HBASE-21595](https://issues.apache.org/jira/browse/HBASE-21595) | *Minor* | **Print thread's information and stack traces when RS is aborting forcibly**
+
+Does thread dump on stdout on abort.
+
+
+---
+
+* [HBASE-21732](https://issues.apache.org/jira/browse/HBASE-21732) | *Critical* | **Should call toUpperCase before using Enum.valueOf in some methods for ColumnFamilyDescriptor**
+
+Now all the Enum configs in ColumnFamilyDescriptor can accept lower case config value.
+
+
+---
+
+* [HBASE-21712](https://issues.apache.org/jira/browse/HBASE-21712) | *Minor* | **Make submit-patch.py python3 compatible**
+
+Python3 support was added to dev-support/submit-patch.py. To install newly required dependencies run \`pip install -r dev-support/python-requirements.txt\` command.
+
+
+---
+
+* [HBASE-21657](https://issues.apache.org/jira/browse/HBASE-21657) | *Major* | **PrivateCellUtil#estimatedSerializedSizeOf has been the bottleneck in 100% scan case.**
+
+In HBASE-21657, I simplified the path of estimatedSerialiedSize() & estimatedSerialiedSizeOfCell() by moving the general getSerializedSize()
+and heapSize() from ExtendedCell to Cell interface. The patch also included some other improvments:
+
+1. For 99% of case, our cells has no tags, so let the HFileScannerImpl just return the NoTagsByteBufferKeyValue if no tags, which means we can save
+ lots of cpu time when sending no tags cell to rpc because can just return the length instead of getting the serialize size by caculating offset/length
+ of each fields(row/cf/cq..)
+2. Move the subclass's getSerializedSize implementation from ExtendedCell to their own class, which mean we did not need to call ExtendedCell's
+ getSerialiedSize() firstly, then forward to subclass's getSerializedSize(withTags).
+3. Give a estimated result arraylist size for avoiding the frequent list extension when in a big scan, now we estimate the array size as min(scan.rows, 512).
+ it's also help a lot.
+
+We gain almost ~40% throughput improvement in 100% scan case for branch-2 (cacheHitRatio~100%)[1], it's a good thing. While it's a incompatible change in
+some case, such as if the upstream user implemented their own Cells, although it's rare but can happen, then their compile will be error.
+
+
+---
+
+* [HBASE-21647](https://issues.apache.org/jira/browse/HBASE-21647) | *Major* | **Add status track for splitting WAL tasks**
+
+Adds task monitor that shows ServerCrashProcedure progress in UI.
+
+
+---
+
+* [HBASE-21652](https://issues.apache.org/jira/browse/HBASE-21652) | *Major* | **Refactor ThriftServer making thrift2 server inherited from thrift1 server**
+
+Before this issue, thrift1 server and thrift2 server are totally different servers. If a new feature is added to thrift1 server, thrfit2 server have to make the same change to support it(e.g. authorization). After this issue, thrift2 server is inherited from thrift1, thrift2 server now have all the features thrift1 server has(e.g http support, which thrift2 server doesn't have before). The way to start thrift1 or thrift2 server remain the same after this issue.
+
+
+---
+
+* [HBASE-21661](https://issues.apache.org/jira/browse/HBASE-21661) | *Major* | **Provide Thrift2 implementation of Table/Admin**
+
+ThriftAdmin/ThriftTable are implemented based on Thrift2. With ThriftAdmin/ThriftTable, People can use thrift2 protocol just like HTable/HBaseAdmin.
+Example of using ThriftConnection
+Configuration conf = HBaseConfiguration.create();
+conf.set(ClusterConnection.HBASE\_CLIENT\_CONNECTION\_IMPL,ThriftConnection.class.getName());
+Connection conn = ConnectionFactory.createConnection(conf);
+Table table = conn.getTable(tablename)
+It is just like a normal Connection, similar use experience with the default ConnectionImplementation
+
+
+---
+
+* [HBASE-21618](https://issues.apache.org/jira/browse/HBASE-21618) | *Critical* | **Scan with the same startRow(inclusive=true) and stopRow(inclusive=false) returns one result**
+
+There was a bug when scan with the same startRow(inclusive=true) and stopRow(inclusive=false). The old incorrect behavior is return one result. After this fix, the new correct behavior is return nothing.
+
+
+---
+
+* [HBASE-21159](https://issues.apache.org/jira/browse/HBASE-21159) | *Major* | **Add shell command to switch throttle on or off**
+
+Support enable or disable rpc throttle when hbase quota is enabled. If hbase quota is enabled, rpc throttle is enabled by default. When disable rpc throttle, HBase will not throttle any request. Use the following commands to switch rpc throttle : enable\_rpc\_throttle / disable\_rpc\_throttle.
+
+
+---
+
+* [HBASE-21659](https://issues.apache.org/jira/browse/HBASE-21659) | *Minor* | **Avoid to load duplicate coprocessors in system config and table descriptor**
+
+Add a new configuration "hbase.skip.load.duplicate.table.coprocessor". The default value is false to keep compatible with the old behavior. Config it true to skip load duplicate table coprocessor.
+
+
+---
+
+* [HBASE-21650](https://issues.apache.org/jira/browse/HBASE-21650) | *Major* | **Add DDL operation and some other miscellaneous to thrift2**
+
+Added DDL operations and some other structure definition to thrift2. Methods added:
+create/modify/addColumnFamily/deleteColumnFamily/modifyColumnFamily/enable/disable/truncate/delete table
+create/modify/delete namespace
+get(list)TableDescriptor(s)/get(list)NamespaceDescirptor(s)
+tableExists/isTableEnabled/isTableDisabled/isTableAvailabe
+And some class definitions along with those methods
+
+
+---
+
+* [HBASE-21643](https://issues.apache.org/jira/browse/HBASE-21643) | *Major* | **Introduce two new region coprocessor method and deprecated postMutationBeforeWAL**
+
+Deprecated region coprocessor postMutationBeforeWAL and introduce two new region coprocessor postIncrementBeforeWAL and postAppendBeforeWAL instead.
+
+
+---
+
+* [HBASE-21635](https://issues.apache.org/jira/browse/HBASE-21635) | *Major* | **Use maven enforcer to ban imports from illegal packages**
+
+Use de.skuzzle.enforcer.restrict-imports-enforcer-rule extension for maven enforcer plugin to ban illegal imports at compile time. Now if you use illegal imports, for example, import com.google.common.\*, there will be a compile error, instead of a checkstyle warning.
+
+
+---
+
+* [HBASE-21401](https://issues.apache.org/jira/browse/HBASE-21401) | *Critical* | **Sanity check when constructing the KeyValue**
+
+Add a sanity check when constructing KeyValue from a byte[]. we use the constructor when we're reading kv from socket or HFIle or WAL(replication). the santiy check isn't designed for discovering the bits corruption in network transferring or disk IO. It is designed to detect bugs inside HBase in advance. and HBASE-21459 indicated that there's extremely small performance loss for diff kinds of keyvalue.
+
+
+---
+
+* [HBASE-21554](https://issues.apache.org/jira/browse/HBASE-21554) | *Minor* | **Show replication endpoint classname for replication peer on master web UI**
+
+The replication UI on master will show the replication endpoint classname.
+
+
+---
+
+* [HBASE-21549](https://issues.apache.org/jira/browse/HBASE-21549) | *Major* | **Add shell command for serial replication peer**
+
+Add a SERIAL flag for add\_peer command to identifiy whether or not the replication peer is a serial replication peer. The default serial flag is false.
+
+
+---
+
+* [HBASE-21453](https://issues.apache.org/jira/browse/HBASE-21453) | *Major* | **Convert ReadOnlyZKClient to DEBUG instead of INFO**
+
+Log level of ReadOnlyZKClient moved to debug.
+
+
+---
+
+* [HBASE-21283](https://issues.apache.org/jira/browse/HBASE-21283) | *Minor* | **Add new shell command 'rit' for listing regions in transition**
+
+<!-- markdown -->
+
+The HBase `shell` now includes a command to list regions currently in transition.
+
+```
+HBase Shell
+Use "help" to get list of supported commands.
+Use "exit" to quit this interactive shell.
+Version 1.5.0-SNAPSHOT, r9bb6d2fa8b760f16cd046657240ebd4ad91cb6de, Mon Oct 8 21:05:50 UTC 2018
+
+hbase(main):001:0> help 'rit'
+List all regions in transition.
+Examples:
+ hbase> rit
+
+hbase(main):002:0> create ...
+0 row(s) in 2.5150 seconds
+=> Hbase::Table - IntegrationTestBigLinkedList
+
+hbase(main):003:0> rit
+0 row(s) in 0.0340 seconds
+
+hbase(main):004:0> unassign '56f0c38c81ae453d19906ce156a2d6a1'
+0 row(s) in 0.0540 seconds
+
+hbase(main):005:0> rit
+IntegrationTestBigLinkedList,L\xCC\xCC\xCC\xCC\xCC\xCC\xCB,1539117183224.56f0c38c81ae453d19906ce156a2d6a1. state=PENDING_CLOSE, ts=Tue Oct 09 20:33:34 UTC 2018 (0s ago), server=null
+1 row(s) in 0.0170 seconds
+```
+
+
+---
+
+* [HBASE-21567](https://issues.apache.org/jira/browse/HBASE-21567) | *Major* | **Allow overriding configs starting up the shell**
+
+Allow passing of -Dkey=value option to shell to override hbase-\* configuration: e.g.:
+
+$ ./bin/hbase shell -Dhbase.zookeeper.quorum=ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org -Draining=false
+...
+hbase(main):001:0\> @shell.hbase.configuration.get("hbase.zookeeper.quorum")
+=\> "ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org"
+hbase(main):002:0\> @shell.hbase.configuration.get("raining")
+=\> "false"
+
+
+---
+
+* [HBASE-21560](https://issues.apache.org/jira/browse/HBASE-21560) | *Major* | **Return a new TableDescriptor for MasterObserver#preModifyTable to allow coprocessor modify the TableDescriptor**
+
+Incompatible change. Allow MasterObserver#preModifyTable to return a new TableDescriptor. And master will use this returned TableDescriptor to modify table.
+
+
+---
+
+* [HBASE-21551](https://issues.apache.org/jira/browse/HBASE-21551) | *Blocker* | **Memory leak when use scan with STREAM at server side**
+
+<!-- markdown -->
+### Summary
+HBase clusters will experience Region Server failures due to out of memory errors due to a leak given any of the following:
+
+* User initiates Scan operations set to use the STREAM reading type
+* User initiates Scan operations set to use the default reading type that read more than 4 * the block size of column families involved in the scan (e.g. by default 4*64KiB)
+* Compactions run
+
+### Root cause
+
+When there are long running scans the Region Server process attempts to optimize access by using a different API geared towards sequential access. Due to an error in HBASE-20704 for HBase 2.0+ the Region Server fails to release related resources when those scans finish. That same optimization path is always used for the HBase internal file compaction process.
+
+### Workaround
+
+Impact for this error can be minimized by setting the config value “hbase.storescanner.pread.max.bytes” to MAX_INT to avoid the optimization for default user scans. Clients should also be checked to ensure they do not pass the STREAM read type to the Scan API. This will have a severe impact on performance for long scans.
+
+Compactions always use this sequential optimized reading mechanism so downstream users will need to periodically restart Region Server roles after compactions have happened.
+
+
+---
+
+* [HBASE-21550](https://issues.apache.org/jira/browse/HBASE-21550) | *Major* | **Add a new method preCreateTableRegionInfos for MasterObserver which allows CPs to modify the TableDescriptor**
+
+Add a new method preCreateTableRegionInfos for MasterObserver, which will be called before creating region infos for the given table, before the preCreateTable method. It allows you to return a new TableDescritor to override the original one. Returns null or throws exception will stop the creation.
+
+
+---
+
+* [HBASE-21492](https://issues.apache.org/jira/browse/HBASE-21492) | *Critical* | **CellCodec Written To WAL Before It's Verified**
+
+After HBASE-21492 the return type of WALCellCodec#getWALCellCodecClass has been changed from String to Class
+
+
+---
+
+* [HBASE-21387](https://issues.apache.org/jira/browse/HBASE-21387) | *Major* | **Race condition surrounding in progress snapshot handling in snapshot cache leads to loss of snapshot files**
+
+To prevent race condition between in progress snapshot (performed by TakeSnapshotHandler) and HFileCleaner which results in data loss, this JIRA introduced mutual exclusion between taking snapshot and running HFileCleaner. That is, at any given moment, either some snapshot can be taken or, HFileCleaner checks hfiles which are not referenced, but not both can be running.
+
+
+---
+
+* [HBASE-21452](https://issues.apache.org/jira/browse/HBASE-21452) | *Major* | **Illegal character in hbase counters group name**
+
+Changes group name of hbase metrics from "HBase Counters" to "HBaseCounters".
+
+
+---
+
+* [HBASE-21443](https://issues.apache.org/jira/browse/HBASE-21443) | *Major* | **[hbase-connectors] Purge hbase-\* modules from core now they've been moved to hbase-connectors**
+
+Parent issue moved hbase-spark\* modules to hbase-connectors. This issue removes hbase-spark\* modules from hbase core repo.
+
+
+---
+
+* [HBASE-21430](https://issues.apache.org/jira/browse/HBASE-21430) | *Major* | **[hbase-connectors] Move hbase-spark\* modules to hbase-connectors repo**
+
+hbase-spark\* modules have been cloned to https://github.com/apache/hbase-connectors All spark connector dev is to happen in that repo from here on out.
+
+Let me file a subtask to remove hbase-spark\* modules from hbase core.
+
+
+---
+
+* [HBASE-21417](https://issues.apache.org/jira/browse/HBASE-21417) | *Critical* | **Pre commit build is broken due to surefire plugin crashes**
+
+Add -Djdk.net.URLClassPath.disableClassPathURLCheck=true when executing surefire plugin.
+
+
+---
+
+* [HBASE-21191](https://issues.apache.org/jira/browse/HBASE-21191) | *Major* | **Add a holding-pattern if no assign for meta or namespace (Can happen if masterprocwals have been cleared).**
+
+Puts master startup into holding pattern if meta is not assigned (previous it would exit). To make progress again, operator needs to inject an assign (Caveats and instruction can be found in HBASE-21035).
+
+
+---
+
+* [HBASE-21322](https://issues.apache.org/jira/browse/HBASE-21322) | *Critical* | **Add a scheduleServerCrashProcedure() API to HbckService**
+
+Adds scheduleServerCrashProcedure to the HbckService.
+
+
+---
+
+* [HBASE-21325](https://issues.apache.org/jira/browse/HBASE-21325) | *Major* | **Force to terminate regionserver when abort hang in somewhere**
+
+Add two new config hbase.regionserver.abort.timeout and hbase.regionserver.abort.timeout.task. If regionserver abort timeout, it will schedule an abort timeout task to run. The default abort task is SystemExitWhenAbortTimeout, which will force to terminate region server when abort timeout. And you can config a special abort timeout task by hbase.regionserver.abort.timeout.task.
+
+
+---
+
+* [HBASE-21215](https://issues.apache.org/jira/browse/HBASE-21215) | *Major* | **Figure how to invoke hbck2; make it easy to find**
+
+Adds to bin/hbase means of invoking hbck2. Pass the new '-j' option on the 'hbck' command with a value of the full path to the HBCK2.jar.
+
+E.g:
+
+$ ./bin/hbase hbck -j ~/checkouts/hbase-operator-tools/hbase-hbck2/target/hbase-hbck2-1.0.0-SNAPSHOT.jar setTableState x ENABLED
+
+
+---
+
+* [HBASE-21372](https://issues.apache.org/jira/browse/HBASE-21372) | *Major* | **Set hbase.assignment.maximum.attempts to Long.MAX**
+
+Retry assigns 'forever' (or until an intervention such as a ServerCrashProcedure).
+
+Previous retry was a maximum of ten times but on failure, handling was an indeterminate.
+
+
+---
+
+* [HBASE-21338](https://issues.apache.org/jira/browse/HBASE-21338) | *Major* | **[balancer] If balancer is an ill-fit for cluster size, it gives little indication**
+
+The description claims the balancer not dynamically configurable but this is an error; it is http://hbase.apache.org/book.html#dyn\_config
+
+Also, if balancer is seen to be cutting out too soon, try setting "hbase.master.balancer.stochastic.runMaxSteps" to true.
+
+Adds cleaner logging around balancer start.
+
+
+---
+
+* [HBASE-21073](https://issues.apache.org/jira/browse/HBASE-21073) | *Major* | **"Maintenance mode" master**
+
+ Instead of being an ephemeral state set by hbck, maintenance mode is now
+ an explicit toggle set by either configuration property or environment
+ variable. In maintenance mode, master will host system tables and not
+ assign any user-space tables to RSs. This gives operators the ability to
+ affect repairs to meta table with fewer moving parts.
+
+
+---
+
+* [HBASE-21335](https://issues.apache.org/jira/browse/HBASE-21335) | *Critical* | **Change the default wait time of HBCK2 tool**
+
+Changed waitTime parameter to lockWait on bypass. Changed default waitTime from 0 -- i.e. wait for ever -- to 1ms so if lock is held, we'll go past it and if override enforce bypass.
+
+
+---
+
+* [HBASE-21291](https://issues.apache.org/jira/browse/HBASE-21291) | *Major* | **Add a test for bypassing stuck state-machine procedures**
+
+bypass will now throw an Exception if passed a lockWait \<= 0; i.e bypass will prevent an operator getting stuck on an entity lock waiting forever (lockWait == 0)
+
+
+---
+
+* [HBASE-21320](https://issues.apache.org/jira/browse/HBASE-21320) | *Major* | **[canary] Cleanup of usage and add commentary**
+
+Cleans up usage and docs around Canary. Does not change command-line args (though we should -- smile).
+
+
+---
+
+* [HBASE-21278](https://issues.apache.org/jira/browse/HBASE-21278) | *Critical* | **Do not rollback successful sub procedures when rolling back a procedure**
+
+For the sub procedures which are successfully finished, do not do rollback. This is a change in rollback behavior.
+
+State changes which are done by sub procedures should be handled by parent procedures when rolling back. For example, when rolling back a MergeTableProcedure, we will schedule new procedures to bring the offline regions online instead of rolling back the original procedures which off-lined the regions (in fact these procedures can not be rolled back...).
+
+
+---
+
+* [HBASE-21158](https://issues.apache.org/jira/browse/HBASE-21158) | *Critical* | **Empty qualifier cell should not be returned if it does not match QualifierFilter**
+
+<!-- markdown -->
+
+Scans that make use of `QualifierFilter` previously would erroneously return both columns with an empty qualifier along with those that matched. After this change that behavior has changed to only return those columns that match.
+
+
+---
+
+* [HBASE-21098](https://issues.apache.org/jira/browse/HBASE-21098) | *Major* | **Improve Snapshot Performance with Temporary Snapshot Directory when rootDir on S3**
+
+It is recommended to place the working directory on-cluster on HDFS as doing so has shown a strong performance increase due to data locality. It is important to note that the working directory should not overlap with any existing directories as the working directory will be cleaned out during the snapshot process. Beyond that, any well-named directory on HDFS should be sufficient.
+
+
+---
+
+* [HBASE-21185](https://issues.apache.org/jira/browse/HBASE-21185) | *Minor* | **WALPrettyPrinter: Additional useful info to be printed by wal printer tool, for debugability purposes**
+
+This adds two extra features to WALPrettyPrinter tool:
+
+1) Output for each cell combined size of cell descriptors, plus the cell value itself, in a given WAL edit. This is printed on the results as "cell total size sum:" info by default;
+
+2) An optional -g/--goto argument, that allows to seek straight to that specific WAL file position, then sequentially reading the WAL from that point towards its end;
+
+
+---
+
+* [HBASE-21287](https://issues.apache.org/jira/browse/HBASE-21287) | *Major* | **JVMClusterUtil Master initialization wait time not configurable**
+
+Local HBase cluster (as used by unit tests) wait times on startup and initialization can be configured via \`hbase.master.start.timeout.localHBaseCluster\` and \`hbase.master.init.timeout.localHBaseCluster\`
+
+
+---
+
+* [HBASE-21280](https://issues.apache.org/jira/browse/HBASE-21280) | *Trivial* | **Add anchors for each heading in UI**
+
+Adds anchors #tables, #tasks, etc.
+
+
+---
+
+* [HBASE-21232](https://issues.apache.org/jira/browse/HBASE-21232) | *Major* | **Show table state in Tables view on Master home page**
+
+Add table state column to the tables panel
+
+
+---
+
+* [HBASE-21223](https://issues.apache.org/jira/browse/HBASE-21223) | *Critical* | **[amv2] Remove abort\_procedure from shell**
+
+Removed the abort\_procedure command from shell -- dangerous -- and deprecated abortProcedure in Admin API.
+
+
+---
+
+* [HBASE-20636](https://issues.apache.org/jira/browse/HBASE-20636) | *Major* | **Introduce two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED**
+
+Add two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED
+1. ROWPREFIX\_FIXED\_LENGTH: specify the length of the prefix
+2. ROWPREFIX\_DELIMITED: specify the delimiter of the prefix
+Need to specify parameters for these two types of bloomfilter, otherwise the table will fail to create
+Example:
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_FIXED\_LENGTH', CONFIGURATION =\> {'RowPrefixBloomFilter.prefix\_length' =\> '10'}}
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_DELIMITED', CONFIGURATION =\> {'RowPrefixDelimitedBloomFilter.delimiter' =\> '#'}}
+
+
+---
+
+* [HBASE-21156](https://issues.apache.org/jira/browse/HBASE-21156) | *Critical* | **[hbck2] Queue an assign of hbase:meta and bulk assign/unassign**
+
+Adds 'raw' assigns/unassigns to the Hbck Service. Takes a list of encoded region names and bulk assigns/unassigns. Skirts Master 'state' check and does not invoke Coprocessors. For repair only.
+
+Here is what HBCK2 usage looks like now:
+
+{code}
+$ java -cp hbase-hbck2-1.0.0-SNAPSHOT.jar org.apache.hbase.HBCK2
+usage: HBCK2 \<OPTIONS\> COMMAND [\<ARGS\>]
+
+Options:
+ -d,--debug run with debug output
+ -h,--help output this help message
+ --hbase.zookeeper.peerport peerport of target hbase ensemble
+ --hbase.zookeeper.quorum ensemble of target hbase
+ --zookeeper.znode.parent parent znode of target hbase
+
+Commands:
+ setTableState \<TABLENAME\> \<STATE\>
+ Possible table states: ENABLED, DISABLED, DISABLING, ENABLING
+ To read current table state, in the hbase shell run:
+ hbase\> get 'hbase:meta', '\<TABLENAME\>', 'table:state'
+ A value of \\x08\\x00 == ENABLED, \\x08\\x01 == DISABLED, etc.
+ An example making table name 'user' ENABLED:
+ $ HBCK2 setTableState users ENABLED
+ Returns whatever the previous table state was.
+
+ assign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' assign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ e.g. 1588230740 is hard-coded encoding for hbase:meta region and
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 assign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created AssignProcedure or -1 if none.
+
+ unassign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' unassign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 unassign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created UnassignProcedure or -1 if none.
+{code}
+
+
+---
+
+* [HBASE-21021](https://issues.apache.org/jira/browse/HBASE-21021) | *Major* | **Result returned by Append operation should be ordered**
+
+This change ensures Append operations are assembled into the expected order.
+
+
+---
+
+* [HBASE-21171](https://issues.apache.org/jira/browse/HBASE-21171) | *Major* | **[amv2] Tool to parse a directory of MasterProcWALs standalone**
+
+Make it so can run the WAL parse and load system in isolation. Here is an example:
+
+{code}$ HBASE\_OPTS=" -XX:+UnlockDiagnosticVMOptions -XX:+UnlockCommercialFeatures -XX:+FlightRecorder -XX:+DebugNonSafepoints" ./bin/hbase org.apache.hadoop.hbase.procedure2.store.wal.WALProcedureStore ~/big\_set\_of\_masterprocwals/
+{code}
+
+
+---
+
+* [HBASE-21107](https://issues.apache.org/jira/browse/HBASE-21107) | *Minor* | **add a metrics for netty direct memory**
+
+Add a new nettyDirectMemoryUsage under server's ipc metrics to show direct memory usage for netty rpc server.
+
+
+---
+
+* [HBASE-21153](https://issues.apache.org/jira/browse/HBASE-21153) | *Major* | **Shaded client jars should always build in relevant phase to avoid confusion**
+
+Client facing artifacts are now built whenever Maven is run through the "package" goal. Previously, the client facing artifacts would create placeholder jars that skipped repackaging HBase and third-party dependencies unless the "release" profile was active.
+
+Build times may be noticeably longer depending on your build hardware. For example, the Jenkins worker nodes maintained by ASF Infra take ~14% longer to do a full packaging build. An example portability-focused personal laptop took ~25% longer.
+
+
+---
+
+* [HBASE-20942](https://issues.apache.org/jira/browse/HBASE-20942) | *Major* | **Improve RpcServer TRACE logging**
+
+Allows configuration of the length of RPC messages printed to the log at TRACE level via "hbase.ipc.trace.param.size" in RpcServer.
+
+
+---
+
+* [HBASE-20649](https://issues.apache.org/jira/browse/HBASE-20649) | *Minor* | **Validate HFiles do not have PREFIX\_TREE DataBlockEncoding**
+
+<!-- markdown -->
+Users who have previously made use of prefix tree encoding can now check that their existing HFiles no longer contain data that uses it with an additional preupgrade check command.
+
+```
+hbase pre-upgrade validate-hfile
+```
+
+Please see the "HFile Content validation" section of the ref guide's coverage of the pre-upgrade validator tool for usage details.
+
+
+---
+
+* [HBASE-20941](https://issues.apache.org/jira/browse/HBASE-20941) | *Major* | **Create and implement HbckService in master**
+
+Adds an HBCK Service and a first method to force-change-in-table-state for use by an HBCK client effecting 'repair' to a malfunctioning HBase.
+
+
+---
+
+* [HBASE-21071](https://issues.apache.org/jira/browse/HBASE-21071) | *Major* | **HBaseTestingUtility::startMiniCluster() to use builder pattern**
+
+Cleanup all the cluster start override combos in HBaseTestingUtility by adding a StartMiniClusterOption and Builder.
+
+
+---
+
+* [HBASE-21072](https://issues.apache.org/jira/browse/HBASE-21072) | *Major* | **Block out HBCK1 in hbase2**
+
+Fence out hbase-1.x hbck1 instances. Stop them making state changes on an hbase-2.x cluster; they could do damage. We do this by writing the hbck1 lock file into place on hbase-2.x Master start-up.
+
+To disable this new behavior, set hbase.write.hbck1.lock.file to false
+
+
+---
+
+* [HBASE-20881](https://issues.apache.org/jira/browse/HBASE-20881) | *Major* | **Introduce a region transition procedure to handle all the state transition for a region**
+
+Introduced a new TransitRegionStateProcedure to replace the old AssignProcedure/UnassignProcedure/MoveRegionProcedure. In the old code, MRP will not be attached to RegionStateNode, so it can not be interrupted by ServerCrashProcedure, which introduces lots of tricky code to deal with races, and also causes lots of other difficulties on how to prevent scheduling redundant or even conflict procedures for a region.
+
+And now TRSP is the only one procedure which can bring region online or offline. When you want to schedule one, you need to check whether there is already one attached to the RegionStateNode, under the lock of the RegionStateNode. If not just go ahead, and if there is one, then you should do something, for example, give up and fail directly, or tell the TRSP to give up(This is what SCP does). Since the check and attach are both under the lock of RSN, it will greatly reduce the possible r [...]
+
+
+---
+
+* [HBASE-21012](https://issues.apache.org/jira/browse/HBASE-21012) | *Critical* | **Revert the change of serializing TimeRangeTracker**
+
+HFiles generated by 2.0.0, 2.0.1, 2.1.0 are not forward compatible to 1.4.6-, 1.3.2.1-, 1.2.6.1-, and other inactive releases. Why HFile lose compatability is hbase in new versions (2.0.0, 2.0.1, 2.1.0) use protobuf to serialize/deserialize TimeRangeTracker (TRT) while old versions use DataInput/DataOutput. To solve this, We have to put HBASE-21012 to 2.x and put HBASE-21013 in 1.x. For more information, please check HBASE-21008.
+
+
+---
+
+* [HBASE-20965](https://issues.apache.org/jira/browse/HBASE-20965) | *Major* | **Separate region server report requests to new handlers**
+
+After HBASE-20965, we can use MasterFifoRpcScheduler in master to separate RegionServerReport requests to indenpedent handler. To use this feature, please set "hbase.master.rpc.scheduler.factory.class" to
+ "org.apache.hadoop.hbase.ipc.MasterFifoRpcScheduler". Use "hbase.master.server.report.handler.count" to set RegionServerReport handlers count, the default value is half of "hbase.regionserver.handler.count" value, but at least 1, and the other handlers count in master is "hbase.regionserver.handler.count" value minus RegionServerReport handlers count, but at least 1 too.
+
+
+---
+
+* [HBASE-20813](https://issues.apache.org/jira/browse/HBASE-20813) | *Minor* | **Remove RPC quotas when the associated table/Namespace is dropped off**
+
+In previous releases, when a Space Quota was configured on a table or namespace and that table or namespace was deleted, the Space Quota was also deleted. This change improves the implementation so that the same is also done for RPC Quotas.
+
+
+---
+
+* [HBASE-20986](https://issues.apache.org/jira/browse/HBASE-20986) | *Major* | **Separate the config of block size when we do log splitting and write Hlog**
+
+After HBASE-20986, we can set different value to block size of WAL and recovered edits. Both of their default value is 2 \* default HDFS blocksize. And hbase.regionserver.recoverededits.blocksize is for block size of recovered edits while hbase.regionserver.hlog.blocksize is for block size of WAL.
+
+
+---
+
+* [HBASE-20856](https://issues.apache.org/jira/browse/HBASE-20856) | *Minor* | **PITA having to set WAL provider in two places**
+
+With this change if a WAL's meta provider (hbase.wal.meta\_provider) is not explicitly set, it now defaults to whatever hbase.wal.provider is set to. Previous, the two settings operated independently, each with its own default.
+
+This change is operationally incompatible with previous HBase versions because the default WAL meta provider no longer defaults to AsyncFSWALProvider but to hbase.wal.provider.
+
+The thought is that this is more in line with an operator's expectation, that a change in hbase.wal.provider is sufficient to change how WALs are written, especially given hbase.wal.meta\_provider is an obscure configuration and that the very idea that meta regions would have their own wal provider would likely come as a surprise.
+
+
+---
+
+* [HBASE-20538](https://issues.apache.org/jira/browse/HBASE-20538) | *Critical* | **Upgrade our hadoop versions to 2.7.7 and 3.0.3**
+
+Update hadoop-two.version to 2.7.7 and hadoop-three.version to 3.0.3 due to a JDK issue which is solved by HADOOP-15473.
+
+
+---
+
+* [HBASE-20846](https://issues.apache.org/jira/browse/HBASE-20846) | *Major* | **Restore procedure locks when master restarts**
+
+1. Make hasLock method final, and add a locked field in Procedure to record whether we have the lock. We will set it to true in doAcquireLock and to false in doReleaseLock. The sub procedures do not need to manage it any more.
+
+2. Also added a locked field in the proto message. When storing, the field will be set according to the return value of hasLock. And when loading, there is a new field in Procedure called lockedWhenLoading. We will set it to true if the locked field in proto message is true.
+
+3. The reason why we can not set the locked field directly to true by calling doAcquireLock is that, during initialization, most procedures need to wait until master is initialized. So the solution here is that, we introduced a new method called waitInitialized in Procedure, and move the wait master initialized related code from acquireLock to this method. And we added a restoreLock method to Procedure, if lockedWhenLoading is true, we will call the acquireLock to get the lock, but do no [...]
+
+
+---
+
+* [HBASE-20672](https://issues.apache.org/jira/browse/HBASE-20672) | *Minor* | **New metrics ReadRequestRate and WriteRequestRate**
+
+Exposing 2 new metrics in HBase to provide ReadRequestRate and WriteRequestRate at region server level. These metrics give the rate of request handled by the region server and are reset after every monitoring interval.
+
+
+---
+
+* [HBASE-6028](https://issues.apache.org/jira/browse/HBASE-6028) | *Minor* | **Implement a cancel for in-progress compactions**
+
+Added a new command to the shell to switch on/off compactions called "compaction\_switch". Disabling compactions will interrupt any currently ongoing compactions. This setting will be lost on restart of the server. Added the configuration hbase.regionserver.compaction.enabled so user can enable/disable compactions via hbase-site.xml.
+
+
+---
+
+* [HBASE-20884](https://issues.apache.org/jira/browse/HBASE-20884) | *Major* | **Replace usage of our Base64 implementation with java.util.Base64**
+
+Class org.apache.hadoop.hbase.util.Base64 has been removed in it's entirety from HBase 2+. In HBase 1, unused methods have been removed from the class and the audience was changed from Public to Private. This class was originally intended as an internal utility class that could be used externally but thinking since changed; these classes should not have been advertised as public to end-users.
+
+This represents an incompatible change for users who relied on this implementation. An alternative implementation for affected clients is available at java.util.Base64 when using Java 8 or newer; be aware, it may encode/decode differently. For clients seeking to restore this specific implementation, it is available in the public domain for download at http://iharder.sourceforge.net/current/java/base64/
+
+
+---
+
+* [HBASE-20357](https://issues.apache.org/jira/browse/HBASE-20357) | *Major* | **AccessControlClient API Enhancement**
+
+This enhances the AccessControlClient APIs to retrieve the permissions based on namespace, table name, family and qualifier for specific user. AccessControlClient can also validate a user whether allowed to perform specified operations on a particular table.
+Following APIs have been added,
+1) getUserPermissions(Connection connection, String tableRegex, byte[] columnFamily, byte[] columnQualifier, String userName)
+ Scope of retrieving permission will be same as existing.
+2) hasPermission(onnection connection, String tableName, byte[] columnFamily, byte[] columnQualifier, String userName, Permission.Action... actions)
+ Scope of validating user privilege,
+ User can perform self check without any special privilege but ADMIN privilege will be required to perform check for other users.
+ For example, suppose there are two users "userA" & "userB" then there can be below scenarios,
+ a. When userA want to check whether userA have privilege to perform mentioned actions
+ userA don't need ADMIN privilege, as it's a self query.
+ b. When userA want to check whether userB have privilege to perform mentioned actions,
+ userA must have ADMIN or superuser privilege, as it's trying to query for other user.
+
+
+
+Users who have previously made use of prefix tree encoding can now check that their existing HFiles no longer contain data that uses it with an additional preupgrade check command.
+
+```
+hbase pre-upgrade validate-hfile
+```
+
+Please see the "HFile Content validation" section of the ref guide's coverage of the pre-upgrade validator tool for usage details.
+
+
+---
+
+* [HBASE-20941](https://issues.apache.org/jira/browse/HBASE-20941) | *Major* | **Create and implement HbckService in master**
+
+Adds an HBCK Service and a first method to force-change-in-table-state for use by an HBCK client effecting 'repair' to a malfunctioning HBase.
+
+
+---
+
+* [HBASE-21071](https://issues.apache.org/jira/browse/HBASE-21071) | *Major* | **HBaseTestingUtility::startMiniCluster() to use builder pattern**
+
+Cleanup all the cluster start override combos in HBaseTestingUtility by adding a StartMiniClusterOption and Builder.
+
+
+---
+
+* [HBASE-21072](https://issues.apache.org/jira/browse/HBASE-21072) | *Major* | **Block out HBCK1 in hbase2**
+
+Fence out hbase-1.x hbck1 instances. Stop them making state changes on an hbase-2.x cluster; they could do damage. We do this by writing the hbck1 lock file into place on hbase-2.x Master start-up.
+
+To disable this new behavior, set hbase.write.hbck1.lock.file to false
+
+
+---
+
+* [HBASE-20881](https://issues.apache.org/jira/browse/HBASE-20881) | *Major* | **Introduce a region transition procedure to handle all the state transition for a region**
+
+Introduced a new TransitRegionStateProcedure to replace the old AssignProcedure/UnassignProcedure/MoveRegionProcedure. In the old code, MRP will not be attached to RegionStateNode, so it can not be interrupted by ServerCrashProcedure, which introduces lots of tricky code to deal with races, and also causes lots of other difficulties on how to prevent scheduling redundant or even conflict procedures for a region.
+
+And now TRSP is the only one procedure which can bring region online or offline. When you want to schedule one, you need to check whether there is already one attached to the RegionStateNode, under the lock of the RegionStateNode. If not just go ahead, and if there is one, then you should do something, for example, give up and fail directly, or tell the TRSP to give up(This is what SCP does). Since the check and attach are both under the lock of RSN, it will greatly reduce the possible r [...]
+
+
+---
+
+* [HBASE-21012](https://issues.apache.org/jira/browse/HBASE-21012) | *Critical* | **Revert the change of serializing TimeRangeTracker**
+
+HFiles generated by 2.0.0, 2.0.1, 2.1.0 are not forward compatible to 1.4.6-, 1.3.2.1-, 1.2.6.1-, and other inactive releases. Why HFile lose compatability is hbase in new versions (2.0.0, 2.0.1, 2.1.0) use protobuf to serialize/deserialize TimeRangeTracker (TRT) while old versions use DataInput/DataOutput. To solve this, We have to put HBASE-21012 to 2.x and put HBASE-21013 in 1.x. For more information, please check HBASE-21008.
+
+
+---
+
+* [HBASE-20965](https://issues.apache.org/jira/browse/HBASE-20965) | *Major* | **Separate region server report requests to new handlers**
+
+After HBASE-20965, we can use MasterFifoRpcScheduler in master to separate RegionServerReport requests to indenpedent handler. To use this feature, please set "hbase.master.rpc.scheduler.factory.class" to
+ "org.apache.hadoop.hbase.ipc.MasterFifoRpcScheduler". Use "hbase.master.server.report.handler.count" to set RegionServerReport handlers count, the default value is half of "hbase.regionserver.handler.count" value, but at least 1, and the other handlers count in master is "hbase.regionserver.handler.count" value minus RegionServerReport handlers count, but at least 1 too.
+
+
+---
+
+* [HBASE-20813](https://issues.apache.org/jira/browse/HBASE-20813) | *Minor* | **Remove RPC quotas when the associated table/Namespace is dropped off**
+
+In previous releases, when a Space Quota was configured on a table or namespace and that table or namespace was deleted, the Space Quota was also deleted. This change improves the implementation so that the same is also done for RPC Quotas.
+
+
+---
+
+* [HBASE-20986](https://issues.apache.org/jira/browse/HBASE-20986) | *Major* | **Separate the config of block size when we do log splitting and write Hlog**
+
+After HBASE-20986, we can set different value to block size of WAL and recovered edits. Both of their default value is 2 \* default HDFS blocksize. And hbase.regionserver.recoverededits.blocksize is for block size of recovered edits while hbase.regionserver.hlog.blocksize is for block size of WAL.
+
+
+---
+
+* [HBASE-20856](https://issues.apache.org/jira/browse/HBASE-20856) | *Minor* | **PITA having to set WAL provider in two places**
+
+With this change if a WAL's meta provider (hbase.wal.meta\_provider) is not explicitly set, it now defaults to whatever hbase.wal.provider is set to. Previous, the two settings operated independently, each with its own default.
+
+This change is operationally incompatible with previous HBase versions because the default WAL meta provider no longer defaults to AsyncFSWALProvider but to hbase.wal.provider.
+
+The thought is that this is more in line with an operator's expectation, that a change in hbase.wal.provider is sufficient to change how WALs are written, especially given hbase.wal.meta\_provider is an obscure configuration and that the very idea that meta regions would have their own wal provider would likely come as a surprise.
+
+
+---
+
+* [HBASE-20538](https://issues.apache.org/jira/browse/HBASE-20538) | *Critical* | **Upgrade our hadoop versions to 2.7.7 and 3.0.3**
+
+Update hadoop-two.version to 2.7.7 and hadoop-three.version to 3.0.3 due to a JDK issue which is solved by HADOOP-15473.
+
+
+---
+
+* [HBASE-20846](https://issues.apache.org/jira/browse/HBASE-20846) | *Major* | **Restore procedure locks when master restarts**
+
+1. Make hasLock method final, and add a locked field in Procedure to record whether we have the lock. We will set it to true in doAcquireLock and to false in doReleaseLock. The sub procedures do not need to manage it any more.
+
+2. Also added a locked field in the proto message. When storing, the field will be set according to the return value of hasLock. And when loading, there is a new field in Procedure called lockedWhenLoading. We will set it to true if the locked field in proto message is true.
+
+3. The reason why we can not set the locked field directly to true by calling doAcquireLock is that, during initialization, most procedures need to wait until master is initialized. So the solution here is that, we introduced a new method called waitInitialized in Procedure, and move the wait master initialized related code from acquireLock to this method. And we added a restoreLock method to Procedure, if lockedWhenLoading is true, we will call the acquireLock to get the lock, but do no [...]
+
+
+---
+
+* [HBASE-20672](https://issues.apache.org/jira/browse/HBASE-20672) | *Minor* | **New metrics ReadRequestRate and WriteRequestRate**
+
+Exposing 2 new metrics in HBase to provide ReadRequestRate and WriteRequestRate at region server level. These metrics give the rate of request handled by the region server and are reset after every monitoring interval.
+
+
+---
+
+* [HBASE-6028](https://issues.apache.org/jira/browse/HBASE-6028) | *Minor* | **Implement a cancel for in-progress compactions**
+
+Added a new command to the shell to switch on/off compactions called "compaction\_switch". Disabling compactions will interrupt any currently ongoing compactions. This setting will be lost on restart of the server. Added the configuration hbase.regionserver.compaction.enabled so user can enable/disable compactions via hbase-site.xml.
+
+
+---
+
+* [HBASE-20884](https://issues.apache.org/jira/browse/HBASE-20884) | *Major* | **Replace usage of our Base64 implementation with java.util.Base64**
+
+Class org.apache.hadoop.hbase.util.Base64 has been removed in it's entirety from HBase 2+. In HBase 1, unused methods have been removed from the class and the audience was changed from Public to Private. This class was originally intended as an internal utility class that could be used externally but thinking since changed; these classes should not have been advertised as public to end-users.
+
+This represents an incompatible change for users who relied on this implementation. An alternative implementation for affected clients is available at java.util.Base64 when using Java 8 or newer; be aware, it may encode/decode differently. For clients seeking to restore this specific implementation, it is available in the public domain for download at http://iharder.sourceforge.net/current/java/base64/
+
+
+---
+
+* [HBASE-20357](https://issues.apache.org/jira/browse/HBASE-20357) | *Major* | **AccessControlClient API Enhancement**
+
+This enhances the AccessControlClient APIs to retrieve the permissions based on namespace, table name, family and qualifier for specific user. AccessControlClient can also validate a user whether allowed to perform specified operations on a particular table.
+Following APIs have been added,
+1) getUserPermissions(Connection connection, String tableRegex, byte[] columnFamily, byte[] columnQualifier, String userName)
+ Scope of retrieving permission will be same as existing.
+2) hasPermission(onnection connection, String tableName, byte[] columnFamily, byte[] columnQualifier, String userName, Permission.Action... actions)
+ Scope of validating user privilege,
+ User can perform self check without any special privilege but ADMIN privilege will be required to perform check for other users.
+ For example, suppose there are two users "userA" & "userB" then there can be below scenarios,
+ a. When userA want to check whether userA have privilege to perform mentioned actions
+ userA don't need ADMIN privilege, as it's a self query.
+ b. When userA want to check whether userB have privilege to perform mentioned actions,
+ userA must have ADMIN or superuser privilege, as it's trying to query for other user.
+
+
+
+# HBASE 2.2.0 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [HBASE-22155](https://issues.apache.org/jira/browse/HBASE-22155) | *Major* | **Move 2.2.0 on to hbase-thirdparty-2.2.0**
+
+ Updates libs used internally by hbase via hbase-thirdparty as follows:
+
+ gson 2.8.1 -\\\> 2.8.5
+ guava 22.0 -\\\> 27.1-jre
+ pb 3.5.1 -\\\> 3.7.0
+ netty 4.1.17 -\\\> 4.1.34
+ commons-collections4 4.1 -\\\> 4.3
+
+
+---
+
+* [HBASE-22178](https://issues.apache.org/jira/browse/HBASE-22178) | *Major* | **Introduce a createTableAsync with TableDescriptor method in Admin**
+
+Introduced
+
+Future\<Void\> createTableAsync(TableDescriptor);
+
+
+---
+
+* [HBASE-22108](https://issues.apache.org/jira/browse/HBASE-22108) | *Major* | **Avoid passing null in Admin methods**
+
+Introduced these methods:
+void move(byte[]);
+void move(byte[], ServerName);
+Future\<Void\> splitRegionAsync(byte[]);
+
+These methods are deprecated:
+void move(byte[], byte[])
+
+
+---
+
+* [HBASE-22152](https://issues.apache.org/jira/browse/HBASE-22152) | *Major* | **Create a jenkins file for yetus to processing GitHub PR**
+
+Add a new jenkins file for running pre commit check for GitHub PR.
+
+
+---
+
+* [HBASE-22007](https://issues.apache.org/jira/browse/HBASE-22007) | *Major* | **Add restoreSnapshot and cloneSnapshot with acl methods in AsyncAdmin**
+
+Add cloneSnapshot/restoreSnapshot with acl methods in AsyncAdmin.
+
+
+---
+
+* [HBASE-22123](https://issues.apache.org/jira/browse/HBASE-22123) | *Minor* | **REST gateway reports Insufficient permissions exceptions as 404 Not Found**
+
+When insufficient permissions, you now get:
+
+HTTP/1.1 403 Forbidden
+
+on the HTTP side, and in the message
+
+Forbidden
+org.apache.hadoop.hbase.security.AccessDeniedException: org.apache.hadoop.hbase.security.AccessDeniedException: Insufficient permissions for user ‘myuser',action: get, tableName:mytable, family:cf.
+at org.apache.ranger.authorization.hbase.RangerAuthorizationCoprocessor.authorizeAccess(RangerAuthorizationCoprocessor.java:547)
+and the rest of the ADE stack
+
+
+---
+
+* [HBASE-22100](https://issues.apache.org/jira/browse/HBASE-22100) | *Minor* | **False positive for error prone warnings in pre commit job**
+
+Now we will sort the javac WARNING/ERROR before generating diff in pre-commit so we can get a stable output for the error prone. The downside is that we just sort the output lexicographically so the line number will also be sorted lexicographically, which is a bit strange to human.
+
+
+---
+
+* [HBASE-22057](https://issues.apache.org/jira/browse/HBASE-22057) | *Major* | **Impose upper-bound on size of ZK ops sent in a single multi()**
+
+Exposes a new configuration property "zookeeper.multi.max.size" which dictates the maximum size of deletes that HBase will make to ZooKeeper in a single RPC. This property defaults to 1MB, which should fall beneath the default ZooKeeper limit of 2MB, controlled by "jute.maxbuffer".
+
+
+---
+
+* [HBASE-22052](https://issues.apache.org/jira/browse/HBASE-22052) | *Major* | **pom cleaning; filter out jersey-core in hadoop2 to match hadoop3 and remove redunant version specifications**
+
+<!-- markdown -->
+# HBASE 2.2.0 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | *Major* | **Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements**
+
+Moving IA.Public class LossyCounting to IA.Private.
+
+
+---
+
+* [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | *Major* | **Update hadoop check versions for hadoop3 in hbase-personality**
+
+Add hadoop 3.0.3, 3.1.1 3.1.2 in our hadoop check jobs.
+
+
+---
+
+* [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | *Major* | **Dump replication queue should show list of wal files ordered chronologically**
+
+The DumpReplicationQueues tool will now list replication queues sorted in chronological order.
+
+
+---
+
+* [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | *Minor* | **Formatting issues in administration section of book**
+
+Fixes a formatting issue in the administration section of the book, where listing indentation were a little bit off.
+
+
+---
+
+* [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | *Major* | **Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks**
+
+Now the default hadoop-two.version has been changed to 2.8.5, and all hadoop versions before 2.8.2(exclude) will not be supported any more.
+
+
+---
+
+* [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | *Trivial* | **Remove extra/useless +**
+
+Removed extra + in HRegion, HStore and LoadIncrementalHFiles for branch-2 and HRegion and HStore for branch-1.
+
+
+---
+
+* [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | *Trivial* | **Fix completebulkload usage instructions**
+
+Added completebulkload short name for BulkLoadHFilesTool to bin/hbase.
+
+
+---
+
+* [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | *Major* | **Upgrade com.yammer.metrics dependency**
+
+Updated metrics core from 3.2.1 to 3.2.6.
+
+
+---
+
+* [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | *Minor* | **Change rubocop configuration for method length**
+
+The rubocop definition for the maximum method length was set to 75.
+
+
+---
+
+* [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | *Minor* | **Fix Markdown for "Voting on Release Candidates" in book**
+
+Fixes the formatting of the "Voting on Release Candidates" to actually show the quote and code formatting of the RAT check.
+
+
+---
+
+* [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | *Minor* | **Change rubocop config for max line length of 100**
+
+The rubocop configuration in the hbase-shell module now allows a line length with 100 characters, instead of 80 as before. For everything before 2.1.5 this change introduces rubocop itself.
+
+
+---
+
+* [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | *Minor* | **Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS**
+
+This change allows the system and superusers to initiate compactions, even when a space quota violation policy disallows compactions from happening. The original intent behind disallowing of compactions was to prevent end-user compactions from creating undue I/O load, not disallowing \*any\* compaction in the system.
+
+
+---
+
+* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
+
+Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
+
+
+---
+
+* [HBASE-22155](https://issues.apache.org/jira/browse/HBASE-22155) | *Major* | **Move 2.2.0 on to hbase-thirdparty-2.2.0**
+
+ Updates libs used internally by hbase via hbase-thirdparty as follows:
+
+ gson 2.8.1 -\\\> 2.8.5
+ guava 22.0 -\\\> 27.1-jre
+ pb 3.5.1 -\\\> 3.7.0
+ netty 4.1.17 -\\\> 4.1.34
+ commons-collections4 4.1 -\\\> 4.3
+
+
+---
+
+* [HBASE-22178](https://issues.apache.org/jira/browse/HBASE-22178) | *Major* | **Introduce a createTableAsync with TableDescriptor method in Admin**
+
+Introduced
+
+Future\<Void\> createTableAsync(TableDescriptor);
+
+
+---
+
+* [HBASE-22108](https://issues.apache.org/jira/browse/HBASE-22108) | *Major* | **Avoid passing null in Admin methods**
+
+Introduced these methods:
+void move(byte[]);
+void move(byte[], ServerName);
+Future\<Void\> splitRegionAsync(byte[]);
+
+These methods are deprecated:
+void move(byte[], byte[])
+
+
+---
+
+* [HBASE-22152](https://issues.apache.org/jira/browse/HBASE-22152) | *Major* | **Create a jenkins file for yetus to processing GitHub PR**
+
+Add a new jenkins file for running pre commit check for GitHub PR.
+
+
+---
+
+* [HBASE-22007](https://issues.apache.org/jira/browse/HBASE-22007) | *Major* | **Add restoreSnapshot and cloneSnapshot with acl methods in AsyncAdmin**
+
+Add cloneSnapshot/restoreSnapshot with acl methods in AsyncAdmin.
+
+
+---
+
+* [HBASE-22123](https://issues.apache.org/jira/browse/HBASE-22123) | *Minor* | **REST gateway reports Insufficient permissions exceptions as 404 Not Found**
+
+When insufficient permissions, you now get:
+
+HTTP/1.1 403 Forbidden
+
+on the HTTP side, and in the message
+
+Forbidden
+org.apache.hadoop.hbase.security.AccessDeniedException: org.apache.hadoop.hbase.security.AccessDeniedException: Insufficient permissions for user ‘myuser',action: get, tableName:mytable, family:cf.
+at org.apache.ranger.authorization.hbase.RangerAuthorizationCoprocessor.authorizeAccess(RangerAuthorizationCoprocessor.java:547)
+and the rest of the ADE stack
+
+
+---
+
+* [HBASE-22100](https://issues.apache.org/jira/browse/HBASE-22100) | *Minor* | **False positive for error prone warnings in pre commit job**
+
+Now we will sort the javac WARNING/ERROR before generating diff in pre-commit so we can get a stable output for the error prone. The downside is that we just sort the output lexicographically so the line number will also be sorted lexicographically, which is a bit strange to human.
+
+
+---
+
+* [HBASE-22057](https://issues.apache.org/jira/browse/HBASE-22057) | *Major* | **Impose upper-bound on size of ZK ops sent in a single multi()**
+
+Exposes a new configuration property "zookeeper.multi.max.size" which dictates the maximum size of deletes that HBase will make to ZooKeeper in a single RPC. This property defaults to 1MB, which should fall beneath the default ZooKeeper limit of 2MB, controlled by "jute.maxbuffer".
+
+
+---
+
+* [HBASE-22052](https://issues.apache.org/jira/browse/HBASE-22052) | *Major* | **pom cleaning; filter out jersey-core in hadoop2 to match hadoop3 and remove redunant version specifications**
+
+<!-- markdown -->
+Fixed awkward dependency issue that prevented site building.
+
+#### note specific to HBase 2.1.4
+HBase 2.1.4 shipped with an early version of this fix that incorrectly altered the libraries included in our binary assembly for using Apache Hadoop 2.7 (the current build default Hadoop version for 2.1.z). For folks running out of the box against a Hadoop 2.7 cluster (or folks who skip the installation step of [replacing the bundled Hadoop libraries](http://hbase.apache.org/book.html#hadoop)) this will result in a failure at Region Server startup due to a missing class definition. e.g.:
+```
+2019-03-27 09:02:05,779 ERROR [main] regionserver.HRegionServer: Failed construction RegionServer
+java.lang.NoClassDefFoundError: org/apache/htrace/SamplerBuilder
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:644)
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:628)
+ at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
+ at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)
+ at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:93)
+ at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2701)
+ at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2683)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:372)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:171)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:356)
+ at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getRootDir(CommonFSUtils.java:362)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.isValidWALRootDir(CommonFSUtils.java:411)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getWALRootDir(CommonFSUtils.java:387)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.initializeFileSystem(HRegionServer.java:704)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.<init>(HRegionServer.java:613)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
+ at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
+ at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.constructRegionServer(HRegionServer.java:3029)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.start(HRegionServerCommandLine.java:63)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.run(HRegionServerCommandLine.java:87)
+ at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
+ at org.apache.hadoop.hbase.util.ServerCommandLine.doMain(ServerCommandLine.java:149)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.main(HRegionServer.java:3047)
+Caused by: java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
+ at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
+ at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
+ ... 26 more
+
+```
+
+Workaround via any _one_ of the following:
+* If you are running against a Hadoop cluster that is 2.8+, ensure you replace the Hadoop libaries in the default binary assembly with those for your version.
+* If you are running against a Hadoop cluster that is 2.8+, build the binary assembly from the source release while specifying your Hadoop version.
+* If you are running against a Hadoop cluster that is a supported 2.7 release, ensure the `hadoop` executable is in the `PATH` seen at Region Server startup and that you are not using the `HBASE_DISABLE_HADOOP_CLASSPATH_LOOKUP` bypass.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers via the HBASE_CLASSPATH environment variable.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers by copying it into the directory `${HBASE_HOME}/lib/client-facing-thirdparty/`.
+
+
+---
+
+* [HBASE-22065](https://issues.apache.org/jira/browse/HBASE-22065) | *Major* | **Add listTableDescriptors(List\<TableName\>) method in AsyncAdmin**
+
+Add a listTableDescriptors(List\<TableName\>) method in the AsyncAdmin interface, to align with the Admin interface.
+
+
+---
+
+* [HBASE-22040](https://issues.apache.org/jira/browse/HBASE-22040) | *Major* | **Add mergeRegionsAsync with a List of region names method in AsyncAdmin**
+
+Add a mergeRegionsAsync(byte[][], boolean) method in the AsyncAdmin interface.
+
+Instead of using assert, now we will throw IllegalArgumentException when you want to merge less than 2 regions at client side. And also, at master side, instead of using assert, now we will throw DoNotRetryIOException if you want merge more than 2 regions, since we only support merging two regions at once for now.
+
+
+---
+
+* [HBASE-22039](https://issues.apache.org/jira/browse/HBASE-22039) | *Major* | **Should add the synchronous parameter for the XXXSwitch method in AsyncAdmin**
+
+Add drainXXX parameter for balancerSwitch/splitSwitch/mergeSwitch methods in the AsyncAdmin interface, which has the same meaning with the synchronous parameter for these methods in the Admin interface.
+
+
+---
+
+* [HBASE-21810](https://issues.apache.org/jira/browse/HBASE-21810) | *Major* | **bulkload support set hfile compression on client**
+
+bulkload (HFileOutputFormat2) support config the compression on client ,you can set the job configuration "hbase.mapreduce.hfileoutputformat.compression" override the auto-detection of the target table's compression
+
+
+---
+
+* [HBASE-22000](https://issues.apache.org/jira/browse/HBASE-22000) | *Major* | **Deprecated isTableAvailable with splitKeys**
+
+Deprecated AsyncTable.isTableAvailable(TableName, byte[][]).
+
+
+---
+
+* [HBASE-21871](https://issues.apache.org/jira/browse/HBASE-21871) | *Major* | **Support to specify a peer table name in VerifyReplication tool**
+
+After HBASE-21871, we can specify a peer table name with --peerTableName in VerifyReplication tool like the following:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable 5 TestTable
+
+In addition, we can compare any 2 tables in any remote clusters with specifying both peerId and --peerTableName.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable zk1,zk2,zk3:2181/hbase TestTable
+
+
+---
+
+* [HBASE-15728](https://issues.apache.org/jira/browse/HBASE-15728) | *Major* | **Add remaining per-table region / store / flush / compaction related metrics**
+
+Adds below flush, split, and compaction metrics
+
+ + // split related metrics
+ + private MutableFastCounter splitRequest;
+ + private MutableFastCounter splitSuccess;
+ + private MetricHistogram splitTimeHisto;
+ +
+ + // flush related metrics
+ + private MetricHistogram flushTimeHisto;
+ + private MetricHistogram flushMemstoreSizeHisto;
+ + private MetricHistogram flushOutputSizeHisto;
+ + private MutableFastCounter flushedMemstoreBytes;
+ + private MutableFastCounter flushedOutputBytes;
+ +
+ + // compaction related metrics
+ + private MetricHistogram compactionTimeHisto;
+ + private MetricHistogram compactionInputFileCountHisto;
+ + private MetricHistogram compactionInputSizeHisto;
+ + private MetricHistogram compactionOutputFileCountHisto;
+ + private MetricHistogram compactionOutputSizeHisto;
+ + private MutableFastCounter compactedInputBytes;
+ + private MutableFastCounter compactedOutputBytes;
+ +
+ + private MetricHistogram majorCompactionTimeHisto;
+ + private MetricHistogram majorCompactionInputFileCountHisto;
+ + private MetricHistogram majorCompactionInputSizeHisto;
+ + private MetricHistogram majorCompactionOutputFileCountHisto;
+ + private MetricHistogram majorCompactionOutputSizeHisto;
+ + private MutableFastCounter majorCompactedInputBytes;
+ + private MutableFastCounter majorCompactedOutputBytes;
+
+
+---
+
+* [HBASE-20886](https://issues.apache.org/jira/browse/HBASE-20886) | *Critical* | **[Auth] Support keytab login in hbase client**
+
+From 2.2.0, hbase supports client login via keytab. To use this feature, client should specify \`hbase.client.keytab.file\` and \`hbase.client.keytab.principal\` in hbase-site.xml, then the connection will contain the needed credentials which be renewed periodically to communicate with kerberized hbase cluster.
+
+
+---
+
+* [HBASE-21410](https://issues.apache.org/jira/browse/HBASE-21410) | *Major* | **A helper page that help find all problematic regions and procedures**
+
+After HBASE-21410, we add a helper page to Master UI. This helper page is mainly to help HBase operator quickly found all regions and pids that are get stuck.
+There are 2 entries to get in this page.
+One is showing in the Regions in Transition section, it made "num region(s) in transition" a link that you can click and check all regions in transition and their related procedure IDs.
+The other one is showing in the table details section, it made the number of CLOSING or OPENING regions a link, which you can click and check regions and related procedure IDs of CLOSING or OPENING regions of a certain table.
+In this helper page, not only you can see all regions and related procedures, there are 2 buttons at the top which will show these regions or procedure IDs in text format. This is mainly aim to help operator to easily copy and paste all problematic procedure IDs and encoded region names to HBCK2's command line, by which we HBase operator can bypass these procedures or assign these regions.
+
+
+---
+
+* [HBASE-21588](https://issues.apache.org/jira/browse/HBASE-21588) | *Major* | **Procedure v2 wal splitting implementation**
+
+After HBASE-21588, we introduce a new way to do WAL splitting coordination by procedure framework. This can simplify the process of WAL splitting and no need to connect zookeeper any more.
+During ServerCrashProcedure, it will create a SplitWALProcedure for each WAL that need to split. Then each SplitWALProcedure will spawn a SplitWALRemoteProcedure to send the request to regionserver.
+At the RegionServer side, whole process is handled by SplitWALCallable. It split the WAL and return the result to master.
+According to my test, this patch has a better performance as the number of WALs that need to split increase. And it can relieve the pressure on zookeeper.
+
+
+---
+
+* [HBASE-20734](https://issues.apache.org/jira/browse/HBASE-20734) | *Major* | **Colocate recovered edits directory with hbase.wal.dir**
+
+Previously the recovered.edits directory was under the root directory. This JIRA moves the recovered.edits directory to be under the hbase.wal.dir if set. It also adds a check for any recovered.edits found under the root directory for backwards compatibility. This gives improvements when a faster media(like SSD) or more local FileSystem is used for the hbase.wal.dir than the root dir.
+
+
+---
+
+* [HBASE-20401](https://issues.apache.org/jira/browse/HBASE-20401) | *Minor* | **Make \`MAX\_WAIT\` and \`waitIfNotFinished\` in CleanerContext configurable**
+
+When oldwals (and hfile) cleaner cleans stale wals (and hfiles), it will periodically check and wait the clean results from filesystem, the total wait time will be no more than a max time.
+
+The periodically wait and check configurations are hbase.oldwals.cleaner.thread.check.interval.msec (default is 500 ms) and hbase.regionserver.hfilecleaner.thread.check.interval.msec (default is 1000 ms).
+
+Meanwhile, The max time configurations are hbase.oldwals.cleaner.thread.timeout.msec and hbase.regionserver.hfilecleaner.thread.timeout.msec, they are set to 60 seconds by default.
+
+All support dynamic configuration.
+
+e.g. in the oldwals cleaning scenario, one may consider tuning hbase.oldwals.cleaner.thread.timeout.msec and hbase.oldwals.cleaner.thread.check.interval.msec
+
+1. While deleting a oldwal never complete (strange but possible), then delete file task needs to wait for a max of 60 seconds. Here, 60 seconds might be too long, or the opposite way is to increase more than 60 seconds in the use cases of slow file delete.
+2. The check and wait of a file delete is set to default in the period of 500 milliseconds, one might want to tune this checking period to a short interval to check more frequently or to a longer interval to avoid checking too often to manage their delete file task checking period (the longer interval may be use to avoid checking too fast while using a high latency storage).
+
+
+---
+
+* [HBASE-21481](https://issues.apache.org/jira/browse/HBASE-21481) | *Major* | **[acl] Superuser's permissions should not be granted or revoked by any non-su global admin**
+
+HBASE-21481 improves the quality of access control, by strengthening the protection of super users's privileges.
+
+
+---
+
+* [HBASE-21082](https://issues.apache.org/jira/browse/HBASE-21082) | *Critical* | **Reimplement assign/unassign related procedure metrics**
+
+Now we have four types of RIT procedure metrics, assign, unassign, move, reopen. The meaning of assign/unassign is changed, as we will not increase the unassign metric and then the assign metric when moving a region.
+Also introduced two new procedure metrics, open and close, which are used to track the open/close region calls to region server. We may send open/close multiple times to finish a RIT since we may retry multiple times.
+
+
+---
+
+* [HBASE-20724](https://issues.apache.org/jira/browse/HBASE-20724) | *Critical* | **Sometimes some compacted storefiles are still opened after region failover**
+
+Problem: This is an old problem since HBASE-2231. The compaction event marker was only writed to WAL. But after flush, the WAL may be archived, which means an useful compaction event marker be deleted, too. So the compacted store files cannot be archived when region open and replay WAL.
+
+Solution: After this jira, the compaction event tracker will be writed to HFile. When region open and load store files, read the compaction evnet tracker from HFile and archive the compacted store files which still exist.
+
+
+---
+
+* [HBASE-21820](https://issues.apache.org/jira/browse/HBASE-21820) | *Major* | **Implement CLUSTER quota scope**
+
+HBase contains two quota scopes: MACHINE and CLUSTER. Before this patch, set quota operations did not expose scope option to client api and use MACHINE as default, CLUSTER scope can not be set and used.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+
+This issue implements CLUSTER scope in a simple way: For user, namespace, user over namespace quota, use [ClusterLimit / RSNum] as machine limit. For table and user over table quota, use [ClusterLimit / TotalTableRegionNum \* MachineTableRegionNum] as machine limit.
+After this patch, user can set CLUSTER scope quota, but MACHINE is still default if user ignore scope.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> MACHINE
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> CLUSTER
+
+
+---
+
+* [HBASE-21057](https://issues.apache.org/jira/browse/HBASE-21057) | *Minor* | **upgrade to latest spotbugs**
+
+Change spotbugs version to 3.1.11.
+
+
+---
+
+* [HBASE-21922](https://issues.apache.org/jira/browse/HBASE-21922) | *Major* | **BloomContext#sanityCheck may failed when use ROWPREFIX\_DELIMITED bloom filter**
+
+Remove bloom filter type ROWPREFIX\_DELIMITED. May add it back when find a better solution.
+
+
+---
+
+* [HBASE-21783](https://issues.apache.org/jira/browse/HBASE-21783) | *Major* | **Support exceed user/table/ns throttle quota if region server has available quota**
+
+Support enable or disable exceed throttle quota. Exceed throttle quota means, user can over consume user/namespace/table quota if region server has additional available quota because other users don't consume at the same time.
+Use the following shell commands to enable/disable exceed throttle quota: enable\_exceed\_throttle\_quota
+disable\_exceed\_throttle\_quota
+There are two limits when enable exceed throttle quota:
+1. Must set at least one read and one write region server throttle quota;
+2. All region server throttle quotas must be in seconds time unit. Because once previous requests exceed their quota and consume region server quota, quota in other time units may be refilled in a long time, this may affect later requests.
+
+
+---
+
+* [HBASE-20587](https://issues.apache.org/jira/browse/HBASE-20587) | *Major* | **Replace Jackson with shaded thirdparty gson**
+
+Remove jackson dependencies from most hbase modules except hbase-rest, use shaded gson instead. The output json will be a bit different since jackson can use getter/setter, but gson will always use the fields.
+
+
+---
+
+* [HBASE-21928](https://issues.apache.org/jira/browse/HBASE-21928) | *Major* | **Deprecated HConstants.META\_QOS**
+
+Mark HConstants.META\_QOS as deprecated. It is for internal use only, which is the highest priority. You should not try to set a priority greater than or equal to this value, although it is no harm but also useless.
+
+
+---
+
+* [HBASE-17942](https://issues.apache.org/jira/browse/HBASE-17942) | *Major* | **Disable region splits and merges per table**
+
+This patch adds the ability to disable split and/or merge for a table (By default, split and merge are enabled for a table).
+
+
+---
+
+* [HBASE-21636](https://issues.apache.org/jira/browse/HBASE-21636) | *Major* | **Enhance the shell scan command to support missing scanner specifications like ReadType, IsolationLevel etc.**
+
+Allows shell to set Scan options previously not exposed. See additions as part of the scan help by typing following hbase shell:
+
+hbase\> help 'scan'
+
+
+---
+
+* [HBASE-21201](https://issues.apache.org/jira/browse/HBASE-21201) | *Major* | **Support to run VerifyReplication MR tool without peerid**
+
+We can specify peerQuorumAddress instead of peerId in VerifyReplication tool. So it no longer requires peerId to be setup when using this tool.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication zk1,zk2,zk3:2181/hbase testTable
+
+
+---
+
+* [HBASE-21838](https://issues.apache.org/jira/browse/HBASE-21838) | *Major* | **Create a special ReplicationEndpoint just for verifying the WAL entries are fine**
+
+Introduce a VerifyWALEntriesReplicationEndpoint which replicates nothing but only verifies if all the cells are valid.
+It can be used to capture bugs for writing WAL, as most times we will not read the WALs again after writing it if there are no region server crashes.
+
+
+---
+
+* [HBASE-21727](https://issues.apache.org/jira/browse/HBASE-21727) | *Minor* | **Simplify documentation around client timeout**
+
+Deprecated HBaseConfiguration#getInt(Configuration, String, String, int) method and removed it from 3.0.0 version.
+
+
+---
+
+* [HBASE-21764](https://issues.apache.org/jira/browse/HBASE-21764) | *Major* | **Size of in-memory compaction thread pool should be configurable**
+
+Introduced an new config key in this issue: hbase.regionserver.inmemory.compaction.pool.size. the default value would be 10. you can configure this to set the pool size of in-memory compaction pool. Note that all memstores in one region server will share the same pool, so if you have many regions in one region server, you need to set this larger to compact faster for better read performance.
+
+
+---
+
+* [HBASE-21684](https://issues.apache.org/jira/browse/HBASE-21684) | *Major* | **Throw DNRIOE when connection or rpc client is closed**
+
+Make StoppedRpcClientException extend DoNotRetryIOException.
+
+
+---
+
+* [HBASE-21739](https://issues.apache.org/jira/browse/HBASE-21739) | *Major* | **Move grant/revoke from regionserver to master**
+
+To implement user permission control in Precedure V2, move grant and revoke method from AccessController to master firstly.
+Mark AccessController#grant and AccessController#revoke as deprecated and please use Admin#grant and Admin#revoke instead.
+
+
+---
+
+* [HBASE-21791](https://issues.apache.org/jira/browse/HBASE-21791) | *Blocker* | **Upgrade thrift dependency to 0.12.0**
+
+IMPORTANT: Due to security issues, all users who use hbase thrift should avoid using releases which do not have this fix.
+
+The effect releases are:
+2.1.x: 2.1.2 and below
+2.0.x: 2.0.4 and below
+1.x: 1.4.x and below
+
+If you are using the effect releases above, please consider upgrading to a newer release ASAP.
+
+
+---
+
+* [HBASE-21792](https://issues.apache.org/jira/browse/HBASE-21792) | *Major* | **Mark HTableMultiplexer as deprecated and remove it in 3.0.0**
+
+HTableMultiplexer exposes the implementation class, and it is incomplete, so we mark it as deprecated and remove it in 3.0.0 release.
+
+There is no direct replacement for HTableMultiplexer, please use BufferedMutator if you want to batch mutations to a table.
+
+
+---
+
+* [HBASE-21782](https://issues.apache.org/jira/browse/HBASE-21782) | *Major* | **LoadIncrementalHFiles should not be IA.Public**
+
+Introduce a BulkLoadHFiles interface which is marked as IA.Public, for doing bulk load programmatically.
+Introduce a BulkLoadHFilesTool which extends BulkLoadHFiles, and is marked as IA.LimitedPrivate(TOOLS), for using from command line.
+The old LoadIncrementalHFiles is deprecated and will be removed in 3.0.0.
+
+
+---
+
+* [HBASE-21762](https://issues.apache.org/jira/browse/HBASE-21762) | *Major* | **Move some methods in ClusterConnection to Connection**
+
+Move the two getHbck method from ClusterConnection to Connection, and mark the methods as IA.LimitedPrivate(HBCK), as ClusterConnection is IA.Private and should not be depended by HBCK2.
+
+Add a clearRegionLocationCache method in Connection to clear the region location cache for all the tables. As in RegionLocator, most of the methods have a 'reload' parameter, which implicitly tells user that we have a region location cache, so adding a method to clear the cache is fine.
+
+
+---
+
+* [HBASE-21713](https://issues.apache.org/jira/browse/HBASE-21713) | *Major* | **Support set region server throttle quota**
+
+Support set region server rpc throttle quota which represents the read/write ability of region servers and throttles when region server's total requests exceeding the limit.
+
+Use the following shell command to set RS quota:
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', THROTTLE\_TYPE =\> WRITE, LIMIT =\> '20000req/sec'
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', LIMIT =\> NONE
+"all" represents the throttle quota of all region servers and setting specified region server quota isn't supported currently.
+
+
+---
+
+* [HBASE-21689](https://issues.apache.org/jira/browse/HBASE-21689) | *Minor* | **Make table/namespace specific current quota info available in shell(describe\_namespace & describe)**
+
+In shell commands "describe\_namespace" and "describe", which are used to see the descriptors of the namespaces and tables respectively, quotas set on that particular namespace/table will also be printed along.
+
+
+---
+
+* [HBASE-17370](https://issues.apache.org/jira/browse/HBASE-17370) | *Major* | **Fix or provide shell scripts to drain and decommission region server**
+
+Adds shell support for the following:
+- List decommissioned/draining region servers
+- Decommission a list of region servers, optionally offload corresponding regions
+- Recommission a region server, optionally load a list of passed regions
+
+
+---
+
+* [HBASE-21734](https://issues.apache.org/jira/browse/HBASE-21734) | *Major* | **Some optimization in FilterListWithOR**
+
+After HBASE-21620, the filterListWithOR has been a bit slow because we need to merge each sub-filter's RC , while before HBASE-21620, we will skip many RC merging, but the logic was wrong. So here we choose another way to optimaze the performance: removing the KeyValueUtil#toNewKeyCell.
+Anoop Sam John suggested that the KeyValueUtil#toNewKeyCell can save some GC before because if we copy key part of cell into a single byte[], then the block the cell refering won't be refered by the filter list any more, the upper layer can GC the data block quickly. while after HBASE-21620, we will update the prevCellList for every encountered cell now, so the lifecycle of cell in prevCellList for FilterList will be quite shorter. so just use the cell ref for saving cpu.
+BTW, we removed all the arrays streams usage in filter list, because it's also quite time-consuming in our test.
+
+
+---
+
+* [HBASE-21738](https://issues.apache.org/jira/browse/HBASE-21738) | *Critical* | **Remove all the CSLM#size operation in our memstore because it's an quite time consuming.**
+
+We found the memstore snapshotting would cost much time because of calling the time-consuming ConcurrentSkipListMap#Size, it would make the p999 latency spike happen. So in this issue, we remove all ConcurrentSkipListMap#size in memstore by counting the cellsCount in MemstoreSizeing. As the issue described, the p999 latency spike was mitigated.
+
+
+---
+
+* [HBASE-21034](https://issues.apache.org/jira/browse/HBASE-21034) | *Major* | **Add new throttle type: read/write capacity unit**
+
+Provides a new throttle type: capacity unit. One read/write/request capacity unit represents that read/write/read+write up to 1K data. If data size is more than 1K, then consume additional capacity units.
+
+Use shell command to set capacity unit(CU):
+set\_quota TYPE =\> THROTTLE, THROTTLE\_TYPE =\> WRITE, USER =\> 'u1', LIMIT =\> '10CU/sec'
+
+Use the "hbase.quota.read.capacity.unit" property to set the data size of one read capacity unit in bytes, the default value is 1K. Use the "hbase.quota.write.capacity.unit" property to set the data size of one write capacity unit in bytes, the default value is 1K.
+
+
+---
+
+* [HBASE-21595](https://issues.apache.org/jira/browse/HBASE-21595) | *Minor* | **Print thread's information and stack traces when RS is aborting forcibly**
+
+Does thread dump on stdout on abort.
+
+
+---
+
+* [HBASE-21732](https://issues.apache.org/jira/browse/HBASE-21732) | *Critical* | **Should call toUpperCase before using Enum.valueOf in some methods for ColumnFamilyDescriptor**
+
+Now all the Enum configs in ColumnFamilyDescriptor can accept lower case config value.
+
+
+---
+
+* [HBASE-21712](https://issues.apache.org/jira/browse/HBASE-21712) | *Minor* | **Make submit-patch.py python3 compatible**
+
+Python3 support was added to dev-support/submit-patch.py. To install newly required dependencies run \`pip install -r dev-support/python-requirements.txt\` command.
+
+
+---
+
+* [HBASE-21657](https://issues.apache.org/jira/browse/HBASE-21657) | *Major* | **PrivateCellUtil#estimatedSerializedSizeOf has been the bottleneck in 100% scan case.**
+
+In HBASE-21657, I simplified the path of estimatedSerialiedSize() & estimatedSerialiedSizeOfCell() by moving the general getSerializedSize()
+and heapSize() from ExtendedCell to Cell interface. The patch also included some other improvments:
+
+1. For 99% of case, our cells has no tags, so let the HFileScannerImpl just return the NoTagsByteBufferKeyValue if no tags, which means we can save
+ lots of cpu time when sending no tags cell to rpc because can just return the length instead of getting the serialize size by caculating offset/length
+ of each fields(row/cf/cq..)
+2. Move the subclass's getSerializedSize implementation from ExtendedCell to their own class, which mean we did not need to call ExtendedCell's
+ getSerialiedSize() firstly, then forward to subclass's getSerializedSize(withTags).
+3. Give a estimated result arraylist size for avoiding the frequent list extension when in a big scan, now we estimate the array size as min(scan.rows, 512).
+ it's also help a lot.
+
+We gain almost ~40% throughput improvement in 100% scan case for branch-2 (cacheHitRatio~100%)[1], it's a good thing. While it's a incompatible change in
+some case, such as if the upstream user implemented their own Cells, although it's rare but can happen, then their compile will be error.
+
+
+---
+
+* [HBASE-21647](https://issues.apache.org/jira/browse/HBASE-21647) | *Major* | **Add status track for splitting WAL tasks**
+
+Adds task monitor that shows ServerCrashProcedure progress in UI.
+
+
+---
+
+* [HBASE-21652](https://issues.apache.org/jira/browse/HBASE-21652) | *Major* | **Refactor ThriftServer making thrift2 server inherited from thrift1 server**
+
+Before this issue, thrift1 server and thrift2 server are totally different servers. If a new feature is added to thrift1 server, thrfit2 server have to make the same change to support it(e.g. authorization). After this issue, thrift2 server is inherited from thrift1, thrift2 server now have all the features thrift1 server has(e.g http support, which thrift2 server doesn't have before). The way to start thrift1 or thrift2 server remain the same after this issue.
+
+
+---
+
+* [HBASE-21661](https://issues.apache.org/jira/browse/HBASE-21661) | *Major* | **Provide Thrift2 implementation of Table/Admin**
+
+ThriftAdmin/ThriftTable are implemented based on Thrift2. With ThriftAdmin/ThriftTable, People can use thrift2 protocol just like HTable/HBaseAdmin.
+Example of using ThriftConnection
+Configuration conf = HBaseConfiguration.create();
+conf.set(ClusterConnection.HBASE\_CLIENT\_CONNECTION\_IMPL,ThriftConnection.class.getName());
+Connection conn = ConnectionFactory.createConnection(conf);
+Table table = conn.getTable(tablename)
+It is just like a normal Connection, similar use experience with the default ConnectionImplementation
+
+
+---
+
+* [HBASE-21618](https://issues.apache.org/jira/browse/HBASE-21618) | *Critical* | **Scan with the same startRow(inclusive=true) and stopRow(inclusive=false) returns one result**
+
+There was a bug when scan with the same startRow(inclusive=true) and stopRow(inclusive=false). The old incorrect behavior is return one result. After this fix, the new correct behavior is return nothing.
+
+
+---
+
+* [HBASE-21159](https://issues.apache.org/jira/browse/HBASE-21159) | *Major* | **Add shell command to switch throttle on or off**
+
+Support enable or disable rpc throttle when hbase quota is enabled. If hbase quota is enabled, rpc throttle is enabled by default. When disable rpc throttle, HBase will not throttle any request. Use the following commands to switch rpc throttle : enable\_rpc\_throttle / disable\_rpc\_throttle.
+
+
+---
+
+* [HBASE-21659](https://issues.apache.org/jira/browse/HBASE-21659) | *Minor* | **Avoid to load duplicate coprocessors in system config and table descriptor**
+
+Add a new configuration "hbase.skip.load.duplicate.table.coprocessor". The default value is false to keep compatible with the old behavior. Config it true to skip load duplicate table coprocessor.
+
+
+---
+
+* [HBASE-21650](https://issues.apache.org/jira/browse/HBASE-21650) | *Major* | **Add DDL operation and some other miscellaneous to thrift2**
+
+Added DDL operations and some other structure definition to thrift2. Methods added:
+create/modify/addColumnFamily/deleteColumnFamily/modifyColumnFamily/enable/disable/truncate/delete table
+create/modify/delete namespace
+get(list)TableDescriptor(s)/get(list)NamespaceDescirptor(s)
+tableExists/isTableEnabled/isTableDisabled/isTableAvailabe
+And some class definitions along with those methods
+
+
+---
+
+* [HBASE-21643](https://issues.apache.org/jira/browse/HBASE-21643) | *Major* | **Introduce two new region coprocessor method and deprecated postMutationBeforeWAL**
+
+Deprecated region coprocessor postMutationBeforeWAL and introduce two new region coprocessor postIncrementBeforeWAL and postAppendBeforeWAL instead.
+
+
+---
+
+* [HBASE-21635](https://issues.apache.org/jira/browse/HBASE-21635) | *Major* | **Use maven enforcer to ban imports from illegal packages**
+
+Use de.skuzzle.enforcer.restrict-imports-enforcer-rule extension for maven enforcer plugin to ban illegal imports at compile time. Now if you use illegal imports, for example, import com.google.common.\*, there will be a compile error, instead of a checkstyle warning.
+
+
+---
+
+* [HBASE-21401](https://issues.apache.org/jira/browse/HBASE-21401) | *Critical* | **Sanity check when constructing the KeyValue**
+
+Add a sanity check when constructing KeyValue from a byte[]. we use the constructor when we're reading kv from socket or HFIle or WAL(replication). the santiy check isn't designed for discovering the bits corruption in network transferring or disk IO. It is designed to detect bugs inside HBase in advance. and HBASE-21459 indicated that there's extremely small performance loss for diff kinds of keyvalue.
+
+
+---
+
+* [HBASE-21554](https://issues.apache.org/jira/browse/HBASE-21554) | *Minor* | **Show replication endpoint classname for replication peer on master web UI**
+
+The replication UI on master will show the replication endpoint classname.
+
+
+---
+
+* [HBASE-21549](https://issues.apache.org/jira/browse/HBASE-21549) | *Major* | **Add shell command for serial replication peer**
+
+Add a SERIAL flag for add\_peer command to identifiy whether or not the replication peer is a serial replication peer. The default serial flag is false.
+
+
+---
+
+* [HBASE-21453](https://issues.apache.org/jira/browse/HBASE-21453) | *Major* | **Convert ReadOnlyZKClient to DEBUG instead of INFO**
+
+Log level of ReadOnlyZKClient moved to debug.
+
+
+---
+
+* [HBASE-21283](https://issues.apache.org/jira/browse/HBASE-21283) | *Minor* | **Add new shell command 'rit' for listing regions in transition**
+
+<!-- markdown -->
+
+The HBase `shell` now includes a command to list regions currently in transition.
+
+```
+HBase Shell
+Use "help" to get list of supported commands.
+Use "exit" to quit this interactive shell.
+Version 1.5.0-SNAPSHOT, r9bb6d2fa8b760f16cd046657240ebd4ad91cb6de, Mon Oct 8 21:05:50 UTC 2018
+
+hbase(main):001:0> help 'rit'
+List all regions in transition.
+Examples:
+ hbase> rit
+
+hbase(main):002:0> create ...
+0 row(s) in 2.5150 seconds
+=> Hbase::Table - IntegrationTestBigLinkedList
+
+hbase(main):003:0> rit
+0 row(s) in 0.0340 seconds
+
+hbase(main):004:0> unassign '56f0c38c81ae453d19906ce156a2d6a1'
+0 row(s) in 0.0540 seconds
+
+hbase(main):005:0> rit
+IntegrationTestBigLinkedList,L\xCC\xCC\xCC\xCC\xCC\xCC\xCB,1539117183224.56f0c38c81ae453d19906ce156a2d6a1. state=PENDING_CLOSE, ts=Tue Oct 09 20:33:34 UTC 2018 (0s ago), server=null
+1 row(s) in 0.0170 seconds
+```
+
+
+---
+
+* [HBASE-21567](https://issues.apache.org/jira/browse/HBASE-21567) | *Major* | **Allow overriding configs starting up the shell**
+
+Allow passing of -Dkey=value option to shell to override hbase-\* configuration: e.g.:
+
+$ ./bin/hbase shell -Dhbase.zookeeper.quorum=ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org -Draining=false
+...
+hbase(main):001:0\> @shell.hbase.configuration.get("hbase.zookeeper.quorum")
+=\> "ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org"
+hbase(main):002:0\> @shell.hbase.configuration.get("raining")
+=\> "false"
+
+
+---
+
+* [HBASE-21560](https://issues.apache.org/jira/browse/HBASE-21560) | *Major* | **Return a new TableDescriptor for MasterObserver#preModifyTable to allow coprocessor modify the TableDescriptor**
+
+Incompatible change. Allow MasterObserver#preModifyTable to return a new TableDescriptor. And master will use this returned TableDescriptor to modify table.
+
+
+---
+
+* [HBASE-21551](https://issues.apache.org/jira/browse/HBASE-21551) | *Blocker* | **Memory leak when use scan with STREAM at server side**
+
+<!-- markdown -->
+### Summary
+HBase clusters will experience Region Server failures due to out of memory errors due to a leak given any of the following:
+
+* User initiates Scan operations set to use the STREAM reading type
+* User initiates Scan operations set to use the default reading type that read more than 4 * the block size of column families involved in the scan (e.g. by default 4*64KiB)
+* Compactions run
+
+### Root cause
+
+When there are long running scans the Region Server process attempts to optimize access by using a different API geared towards sequential access. Due to an error in HBASE-20704 for HBase 2.0+ the Region Server fails to release related resources when those scans finish. That same optimization path is always used for the HBase internal file compaction process.
+
+### Workaround
+
+Impact for this error can be minimized by setting the config value “hbase.storescanner.pread.max.bytes” to MAX_INT to avoid the optimization for default user scans. Clients should also be checked to ensure they do not pass the STREAM read type to the Scan API. This will have a severe impact on performance for long scans.
+
+Compactions always use this sequential optimized reading mechanism so downstream users will need to periodically restart Region Server roles after compactions have happened.
+
+
+---
+
+* [HBASE-21550](https://issues.apache.org/jira/browse/HBASE-21550) | *Major* | **Add a new method preCreateTableRegionInfos for MasterObserver which allows CPs to modify the TableDescriptor**
+
+Add a new method preCreateTableRegionInfos for MasterObserver, which will be called before creating region infos for the given table, before the preCreateTable method. It allows you to return a new TableDescritor to override the original one. Returns null or throws exception will stop the creation.
+
+
+---
+
+* [HBASE-21492](https://issues.apache.org/jira/browse/HBASE-21492) | *Critical* | **CellCodec Written To WAL Before It's Verified**
+
+After HBASE-21492 the return type of WALCellCodec#getWALCellCodecClass has been changed from String to Class
+
+
+---
+
+* [HBASE-21387](https://issues.apache.org/jira/browse/HBASE-21387) | *Major* | **Race condition surrounding in progress snapshot handling in snapshot cache leads to loss of snapshot files**
+
+To prevent race condition between in progress snapshot (performed by TakeSnapshotHandler) and HFileCleaner which results in data loss, this JIRA introduced mutual exclusion between taking snapshot and running HFileCleaner. That is, at any given moment, either some snapshot can be taken or, HFileCleaner checks hfiles which are not referenced, but not both can be running.
+
+
+---
+
+* [HBASE-21452](https://issues.apache.org/jira/browse/HBASE-21452) | *Major* | **Illegal character in hbase counters group name**
+
+Changes group name of hbase metrics from "HBase Counters" to "HBaseCounters".
+
+
+---
+
+* [HBASE-21443](https://issues.apache.org/jira/browse/HBASE-21443) | *Major* | **[hbase-connectors] Purge hbase-\* modules from core now they've been moved to hbase-connectors**
+
+Parent issue moved hbase-spark\* modules to hbase-connectors. This issue removes hbase-spark\* modules from hbase core repo.
+
+
+---
+
+* [HBASE-21430](https://issues.apache.org/jira/browse/HBASE-21430) | *Major* | **[hbase-connectors] Move hbase-spark\* modules to hbase-connectors repo**
+
+hbase-spark\* modules have been cloned to https://github.com/apache/hbase-connectors All spark connector dev is to happen in that repo from here on out.
+
+Let me file a subtask to remove hbase-spark\* modules from hbase core.
+
+
+---
+
+* [HBASE-21417](https://issues.apache.org/jira/browse/HBASE-21417) | *Critical* | **Pre commit build is broken due to surefire plugin crashes**
+
+Add -Djdk.net.URLClassPath.disableClassPathURLCheck=true when executing surefire plugin.
+
+
+---
+
+* [HBASE-21191](https://issues.apache.org/jira/browse/HBASE-21191) | *Major* | **Add a holding-pattern if no assign for meta or namespace (Can happen if masterprocwals have been cleared).**
+
+Puts master startup into holding pattern if meta is not assigned (previous it would exit). To make progress again, operator needs to inject an assign (Caveats and instruction can be found in HBASE-21035).
+
+
+---
+
+* [HBASE-21322](https://issues.apache.org/jira/browse/HBASE-21322) | *Critical* | **Add a scheduleServerCrashProcedure() API to HbckService**
+
+Adds scheduleServerCrashProcedure to the HbckService.
+
+
+---
+
+* [HBASE-21325](https://issues.apache.org/jira/browse/HBASE-21325) | *Major* | **Force to terminate regionserver when abort hang in somewhere**
+
+Add two new config hbase.regionserver.abort.timeout and hbase.regionserver.abort.timeout.task. If regionserver abort timeout, it will schedule an abort timeout task to run. The default abort task is SystemExitWhenAbortTimeout, which will force to terminate region server when abort timeout. And you can config a special abort timeout task by hbase.regionserver.abort.timeout.task.
+
+
+---
+
+* [HBASE-21215](https://issues.apache.org/jira/browse/HBASE-21215) | *Major* | **Figure how to invoke hbck2; make it easy to find**
+
+Adds to bin/hbase means of invoking hbck2. Pass the new '-j' option on the 'hbck' command with a value of the full path to the HBCK2.jar.
+
+E.g:
+
+$ ./bin/hbase hbck -j ~/checkouts/hbase-operator-tools/hbase-hbck2/target/hbase-hbck2-1.0.0-SNAPSHOT.jar setTableState x ENABLED
+
+
+---
+
+* [HBASE-21372](https://issues.apache.org/jira/browse/HBASE-21372) | *Major* | **Set hbase.assignment.maximum.attempts to Long.MAX**
+
+Retry assigns 'forever' (or until an intervention such as a ServerCrashProcedure).
+
+Previous retry was a maximum of ten times but on failure, handling was an indeterminate.
+
+
+---
+
+* [HBASE-21338](https://issues.apache.org/jira/browse/HBASE-21338) | *Major* | **[balancer] If balancer is an ill-fit for cluster size, it gives little indication**
+
+The description claims the balancer not dynamically configurable but this is an error; it is http://hbase.apache.org/book.html#dyn\_config
+
+Also, if balancer is seen to be cutting out too soon, try setting "hbase.master.balancer.stochastic.runMaxSteps" to true.
+
+Adds cleaner logging around balancer start.
+
+
+---
+
+* [HBASE-21073](https://issues.apache.org/jira/browse/HBASE-21073) | *Major* | **"Maintenance mode" master**
+
+ Instead of being an ephemeral state set by hbck, maintenance mode is now
+ an explicit toggle set by either configuration property or environment
+ variable. In maintenance mode, master will host system tables and not
+ assign any user-space tables to RSs. This gives operators the ability to
+ affect repairs to meta table with fewer moving parts.
+
+
+---
+
+* [HBASE-21335](https://issues.apache.org/jira/browse/HBASE-21335) | *Critical* | **Change the default wait time of HBCK2 tool**
+
+Changed waitTime parameter to lockWait on bypass. Changed default waitTime from 0 -- i.e. wait for ever -- to 1ms so if lock is held, we'll go past it and if override enforce bypass.
+
+
+---
+
+* [HBASE-21291](https://issues.apache.org/jira/browse/HBASE-21291) | *Major* | **Add a test for bypassing stuck state-machine procedures**
+
+bypass will now throw an Exception if passed a lockWait \<= 0; i.e bypass will prevent an operator getting stuck on an entity lock waiting forever (lockWait == 0)
+
+
+---
+
+* [HBASE-21320](https://issues.apache.org/jira/browse/HBASE-21320) | *Major* | **[canary] Cleanup of usage and add commentary**
+
+Cleans up usage and docs around Canary. Does not change command-line args (though we should -- smile).
+
+
+---
+
+* [HBASE-21278](https://issues.apache.org/jira/browse/HBASE-21278) | *Critical* | **Do not rollback successful sub procedures when rolling back a procedure**
+
+For the sub procedures which are successfully finished, do not do rollback. This is a change in rollback behavior.
+
+State changes which are done by sub procedures should be handled by parent procedures when rolling back. For example, when rolling back a MergeTableProcedure, we will schedule new procedures to bring the offline regions online instead of rolling back the original procedures which off-lined the regions (in fact these procedures can not be rolled back...).
+
+
+---
+
+* [HBASE-21158](https://issues.apache.org/jira/browse/HBASE-21158) | *Critical* | **Empty qualifier cell should not be returned if it does not match QualifierFilter**
+
+<!-- markdown -->
+
+Scans that make use of `QualifierFilter` previously would erroneously return both columns with an empty qualifier along with those that matched. After this change that behavior has changed to only return those columns that match.
+
+
+---
+
+* [HBASE-21098](https://issues.apache.org/jira/browse/HBASE-21098) | *Major* | **Improve Snapshot Performance with Temporary Snapshot Directory when rootDir on S3**
+
+It is recommended to place the working directory on-cluster on HDFS as doing so has shown a strong performance increase due to data locality. It is important to note that the working directory should not overlap with any existing directories as the working directory will be cleaned out during the snapshot process. Beyond that, any well-named directory on HDFS should be sufficient.
+
+
+---
+
+* [HBASE-21185](https://issues.apache.org/jira/browse/HBASE-21185) | *Minor* | **WALPrettyPrinter: Additional useful info to be printed by wal printer tool, for debugability purposes**
+
+This adds two extra features to WALPrettyPrinter tool:
+
+1) Output for each cell combined size of cell descriptors, plus the cell value itself, in a given WAL edit. This is printed on the results as "cell total size sum:" info by default;
+
+2) An optional -g/--goto argument, that allows to seek straight to that specific WAL file position, then sequentially reading the WAL from that point towards its end;
+
+
+---
+
+* [HBASE-21287](https://issues.apache.org/jira/browse/HBASE-21287) | *Major* | **JVMClusterUtil Master initialization wait time not configurable**
+
+Local HBase cluster (as used by unit tests) wait times on startup and initialization can be configured via \`hbase.master.start.timeout.localHBaseCluster\` and \`hbase.master.init.timeout.localHBaseCluster\`
+
+
+---
+
+* [HBASE-21280](https://issues.apache.org/jira/browse/HBASE-21280) | *Trivial* | **Add anchors for each heading in UI**
+
+Adds anchors #tables, #tasks, etc.
+
+
+---
+
+* [HBASE-21232](https://issues.apache.org/jira/browse/HBASE-21232) | *Major* | **Show table state in Tables view on Master home page**
+
+Add table state column to the tables panel
+
+
+---
+
+* [HBASE-21223](https://issues.apache.org/jira/browse/HBASE-21223) | *Critical* | **[amv2] Remove abort\_procedure from shell**
+
+Removed the abort\_procedure command from shell -- dangerous -- and deprecated abortProcedure in Admin API.
+
+
+---
+
+* [HBASE-20636](https://issues.apache.org/jira/browse/HBASE-20636) | *Major* | **Introduce two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED**
+
+Add two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED
+1. ROWPREFIX\_FIXED\_LENGTH: specify the length of the prefix
+2. ROWPREFIX\_DELIMITED: specify the delimiter of the prefix
+Need to specify parameters for these two types of bloomfilter, otherwise the table will fail to create
+Example:
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_FIXED\_LENGTH', CONFIGURATION =\> {'RowPrefixBloomFilter.prefix\_length' =\> '10'}}
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_DELIMITED', CONFIGURATION =\> {'RowPrefixDelimitedBloomFilter.delimiter' =\> '#'}}
+
+
+---
+
+* [HBASE-21156](https://issues.apache.org/jira/browse/HBASE-21156) | *Critical* | **[hbck2] Queue an assign of hbase:meta and bulk assign/unassign**
+
+Adds 'raw' assigns/unassigns to the Hbck Service. Takes a list of encoded region names and bulk assigns/unassigns. Skirts Master 'state' check and does not invoke Coprocessors. For repair only.
+
+Here is what HBCK2 usage looks like now:
+
+{code}
+$ java -cp hbase-hbck2-1.0.0-SNAPSHOT.jar org.apache.hbase.HBCK2
+usage: HBCK2 \<OPTIONS\> COMMAND [\<ARGS\>]
+
+Options:
+ -d,--debug run with debug output
+ -h,--help output this help message
+ --hbase.zookeeper.peerport peerport of target hbase ensemble
+ --hbase.zookeeper.quorum ensemble of target hbase
+ --zookeeper.znode.parent parent znode of target hbase
+
+Commands:
+ setTableState \<TABLENAME\> \<STATE\>
+ Possible table states: ENABLED, DISABLED, DISABLING, ENABLING
+ To read current table state, in the hbase shell run:
+ hbase\> get 'hbase:meta', '\<TABLENAME\>', 'table:state'
+ A value of \\x08\\x00 == ENABLED, \\x08\\x01 == DISABLED, etc.
+ An example making table name 'user' ENABLED:
+ $ HBCK2 setTableState users ENABLED
+ Returns whatever the previous table state was.
+
+ assign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' assign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ e.g. 1588230740 is hard-coded encoding for hbase:meta region and
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 assign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created AssignProcedure or -1 if none.
+
+ unassign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' unassign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 unassign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created UnassignProcedure or -1 if none.
+{code}
+
+
+---
+
+* [HBASE-21021](https://issues.apache.org/jira/browse/HBASE-21021) | *Major* | **Result returned by Append operation should be ordered**
+
+This change ensures Append operations are assembled into the expected order.
+
+
+---
+
+* [HBASE-21171](https://issues.apache.org/jira/browse/HBASE-21171) | *Major* | **[amv2] Tool to parse a directory of MasterProcWALs standalone**
+
+Make it so can run the WAL parse and load system in isolation. Here is an example:
+
+{code}$ HBASE\_OPTS=" -XX:+UnlockDiagnosticVMOptions -XX:+UnlockCommercialFeatures -XX:+FlightRecorder -XX:+DebugNonSafepoints" ./bin/hbase org.apache.hadoop.hbase.procedure2.store.wal.WALProcedureStore ~/big\_set\_of\_masterprocwals/
+{code}
+
+
+---
+
+* [HBASE-21107](https://issues.apache.org/jira/browse/HBASE-21107) | *Minor* | **add a metrics for netty direct memory**
+
+Add a new nettyDirectMemoryUsage under server's ipc metrics to show direct memory usage for netty rpc server.
+
+
+---
+
+* [HBASE-21153](https://issues.apache.org/jira/browse/HBASE-21153) | *Major* | **Shaded client jars should always build in relevant phase to avoid confusion**
+
+Client facing artifacts are now built whenever Maven is run through the "package" goal. Previously, the client facing artifacts would create placeholder jars that skipped repackaging HBase and third-party dependencies unless the "release" profile was active.
+
+Build times may be noticeably longer depending on your build hardware. For example, the Jenkins worker nodes maintained by ASF Infra take ~14% longer to do a full packaging build. An example portability-focused personal laptop took ~25% longer.
+
+
+---
+
+* [HBASE-20942](https://issues.apache.org/jira/browse/HBASE-20942) | *Major* | **Improve RpcServer TRACE logging**
+
+Allows configuration of the length of RPC messages printed to the log at TRACE level via "hbase.ipc.trace.param.size" in RpcServer.
+
+
+---
+
+* [HBASE-20649](https://issues.apache.org/jira/browse/HBASE-20649) | *Minor* | **Validate HFiles do not have PREFIX\_TREE DataBlockEncoding**
+
+<!-- markdown -->
+Users who have previously made use of prefix tree encoding can now check that their existing HFiles no longer contain data that uses it with an additional preupgrade check command.
+
+```
+hbase pre-upgrade validate-hfile
+```
+
+Please see the "HFile Content validation" section of the ref guide's coverage of the pre-upgrade validator tool for usage details.
+
+
+---
+
+* [HBASE-20941](https://issues.apache.org/jira/browse/HBASE-20941) | *Major* | **Create and implement HbckService in master**
+
+Adds an HBCK Service and a first method to force-change-in-table-state for use by an HBCK client effecting 'repair' to a malfunctioning HBase.
+
+
+---
+
+* [HBASE-21071](https://issues.apache.org/jira/browse/HBASE-21071) | *Major* | **HBaseTestingUtility::startMiniCluster() to use builder pattern**
+
+Cleanup all the cluster start override combos in HBaseTestingUtility by adding a StartMiniClusterOption and Builder.
+
+
+---
+
+* [HBASE-21072](https://issues.apache.org/jira/browse/HBASE-21072) | *Major* | **Block out HBCK1 in hbase2**
+
+Fence out hbase-1.x hbck1 instances. Stop them making state changes on an hbase-2.x cluster; they could do damage. We do this by writing the hbck1 lock file into place on hbase-2.x Master start-up.
+
+To disable this new behavior, set hbase.write.hbck1.lock.file to false
+
+
+---
+
+* [HBASE-20881](https://issues.apache.org/jira/browse/HBASE-20881) | *Major* | **Introduce a region transition procedure to handle all the state transition for a region**
+
+Introduced a new TransitRegionStateProcedure to replace the old AssignProcedure/UnassignProcedure/MoveRegionProcedure. In the old code, MRP will not be attached to RegionStateNode, so it can not be interrupted by ServerCrashProcedure, which introduces lots of tricky code to deal with races, and also causes lots of other difficulties on how to prevent scheduling redundant or even conflict procedures for a region.
+
+And now TRSP is the only one procedure which can bring region online or offline. When you want to schedule one, you need to check whether there is already one attached to the RegionStateNode, under the lock of the RegionStateNode. If not just go ahead, and if there is one, then you should do something, for example, give up and fail directly, or tell the TRSP to give up(This is what SCP does). Since the check and attach are both under the lock of RSN, it will greatly reduce the possible r [...]
+
+
+---
+
+* [HBASE-21012](https://issues.apache.org/jira/browse/HBASE-21012) | *Critical* | **Revert the change of serializing TimeRangeTracker**
+
+HFiles generated by 2.0.0, 2.0.1, 2.1.0 are not forward compatible to 1.4.6-, 1.3.2.1-, 1.2.6.1-, and other inactive releases. Why HFile lose compatability is hbase in new versions (2.0.0, 2.0.1, 2.1.0) use protobuf to serialize/deserialize TimeRangeTracker (TRT) while old versions use DataInput/DataOutput. To solve this, We have to put HBASE-21012 to 2.x and put HBASE-21013 in 1.x. For more information, please check HBASE-21008.
+
+
+---
+
+* [HBASE-20965](https://issues.apache.org/jira/browse/HBASE-20965) | *Major* | **Separate region server report requests to new handlers**
+
+After HBASE-20965, we can use MasterFifoRpcScheduler in master to separate RegionServerReport requests to indenpedent handler. To use this feature, please set "hbase.master.rpc.scheduler.factory.class" to
+ "org.apache.hadoop.hbase.ipc.MasterFifoRpcScheduler". Use "hbase.master.server.report.handler.count" to set RegionServerReport handlers count, the default value is half of "hbase.regionserver.handler.count" value, but at least 1, and the other handlers count in master is "hbase.regionserver.handler.count" value minus RegionServerReport handlers count, but at least 1 too.
+
+
+---
+
+* [HBASE-20813](https://issues.apache.org/jira/browse/HBASE-20813) | *Minor* | **Remove RPC quotas when the associated table/Namespace is dropped off**
+
+In previous releases, when a Space Quota was configured on a table or namespace and that table or namespace was deleted, the Space Quota was also deleted. This change improves the implementation so that the same is also done for RPC Quotas.
+
+
+---
+
+* [HBASE-20986](https://issues.apache.org/jira/browse/HBASE-20986) | *Major* | **Separate the config of block size when we do log splitting and write Hlog**
+
+After HBASE-20986, we can set different value to block size of WAL and recovered edits. Both of their default value is 2 \* default HDFS blocksize. And hbase.regionserver.recoverededits.blocksize is for block size of recovered edits while hbase.regionserver.hlog.blocksize is for block size of WAL.
+
+
+---
+
+* [HBASE-20856](https://issues.apache.org/jira/browse/HBASE-20856) | *Minor* | **PITA having to set WAL provider in two places**
+
+With this change if a WAL's meta provider (hbase.wal.meta\_provider) is not explicitly set, it now defaults to whatever hbase.wal.provider is set to. Previous, the two settings operated independently, each with its own default.
+
+This change is operationally incompatible with previous HBase versions because the default WAL meta provider no longer defaults to AsyncFSWALProvider but to hbase.wal.provider.
+
+The thought is that this is more in line with an operator's expectation, that a change in hbase.wal.provider is sufficient to change how WALs are written, especially given hbase.wal.meta\_provider is an obscure configuration and that the very idea that meta regions would have their own wal provider would likely come as a surprise.
+
+
+---
+
+* [HBASE-20538](https://issues.apache.org/jira/browse/HBASE-20538) | *Critical* | **Upgrade our hadoop versions to 2.7.7 and 3.0.3**
+
+Update hadoop-two.version to 2.7.7 and hadoop-three.version to 3.0.3 due to a JDK issue which is solved by HADOOP-15473.
+
+
+---
+
+* [HBASE-20846](https://issues.apache.org/jira/browse/HBASE-20846) | *Major* | **Restore procedure locks when master restarts**
+
+1. Make hasLock method final, and add a locked field in Procedure to record whether we have the lock. We will set it to true in doAcquireLock and to false in doReleaseLock. The sub procedures do not need to manage it any more.
+
+2. Also added a locked field in the proto message. When storing, the field will be set according to the return value of hasLock. And when loading, there is a new field in Procedure called lockedWhenLoading. We will set it to true if the locked field in proto message is true.
+
+3. The reason why we can not set the locked field directly to true by calling doAcquireLock is that, during initialization, most procedures need to wait until master is initialized. So the solution here is that, we introduced a new method called waitInitialized in Procedure, and move the wait master initialized related code from acquireLock to this method. And we added a restoreLock method to Procedure, if lockedWhenLoading is true, we will call the acquireLock to get the lock, but do no [...]
+
+
+---
+
+* [HBASE-20672](https://issues.apache.org/jira/browse/HBASE-20672) | *Minor* | **New metrics ReadRequestRate and WriteRequestRate**
+
+Exposing 2 new metrics in HBase to provide ReadRequestRate and WriteRequestRate at region server level. These metrics give the rate of request handled by the region server and are reset after every monitoring interval.
+
+
+---
+
+* [HBASE-6028](https://issues.apache.org/jira/browse/HBASE-6028) | *Minor* | **Implement a cancel for in-progress compactions**
+
+Added a new command to the shell to switch on/off compactions called "compaction\_switch". Disabling compactions will interrupt any currently ongoing compactions. This setting will be lost on restart of the server. Added the configuration hbase.regionserver.compaction.enabled so user can enable/disable compactions via hbase-site.xml.
+
+
+---
+
+* [HBASE-20884](https://issues.apache.org/jira/browse/HBASE-20884) | *Major* | **Replace usage of our Base64 implementation with java.util.Base64**
+
+Class org.apache.hadoop.hbase.util.Base64 has been removed in it's entirety from HBase 2+. In HBase 1, unused methods have been removed from the class and the audience was changed from Public to Private. This class was originally intended as an internal utility class that could be used externally but thinking since changed; these classes should not have been advertised as public to end-users.
+
+This represents an incompatible change for users who relied on this implementation. An alternative implementation for affected clients is available at java.util.Base64 when using Java 8 or newer; be aware, it may encode/decode differently. For clients seeking to restore this specific implementation, it is available in the public domain for download at http://iharder.sourceforge.net/current/java/base64/
+
+
+---
+
+* [HBASE-20357](https://issues.apache.org/jira/browse/HBASE-20357) | *Major* | **AccessControlClient API Enhancement**
+
+This enhances the AccessControlClient APIs to retrieve the permissions based on namespace, table name, family and qualifier for specific user. AccessControlClient can also validate a user whether allowed to perform specified operations on a particular table.
+Following APIs have been added,
+1) getUserPermissions(Connection connection, String tableRegex, byte[] columnFamily, byte[] columnQualifier, String userName)
+ Scope of retrieving permission will be same as existing.
+2) hasPermission(onnection connection, String tableName, byte[] columnFamily, byte[] columnQualifier, String userName, Permission.Action... actions)
+ Scope of validating user privilege,
+ User can perform self check without any special privilege but ADMIN privilege will be required to perform check for other users.
+ For example, suppose there are two users "userA" & "userB" then there can be below scenarios,
+ a. When userA want to check whether userA have privilege to perform mentioned actions
+ userA don't need ADMIN privilege, as it's a self query.
+ b. When userA want to check whether userB have privilege to perform mentioned actions,
+ userA must have ADMIN or superuser privilege, as it's trying to query for other user.
+
+
+
+# HBASE 2.2.0 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
+
+Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
+
+
+---
+
+* [HBASE-22155](https://issues.apache.org/jira/browse/HBASE-22155) | *Major* | **Move 2.2.0 on to hbase-thirdparty-2.2.0**
+
+ Updates libs used internally by hbase via hbase-thirdparty as follows:
+
+ gson 2.8.1 -\\\> 2.8.5
+ guava 22.0 -\\\> 27.1-jre
+ pb 3.5.1 -\\\> 3.7.0
+ netty 4.1.17 -\\\> 4.1.34
+ commons-collections4 4.1 -\\\> 4.3
+
+
+---
+
+* [HBASE-22178](https://issues.apache.org/jira/browse/HBASE-22178) | *Major* | **Introduce a createTableAsync with TableDescriptor method in Admin**
+
+Introduced
+
+Future\<Void\> createTableAsync(TableDescriptor);
+
+
+---
+
+* [HBASE-22108](https://issues.apache.org/jira/browse/HBASE-22108) | *Major* | **Avoid passing null in Admin methods**
+
+Introduced these methods:
+void move(byte[]);
+void move(byte[], ServerName);
+Future\<Void\> splitRegionAsync(byte[]);
+
+These methods are deprecated:
+void move(byte[], byte[])
+
+
+---
+
+* [HBASE-22152](https://issues.apache.org/jira/browse/HBASE-22152) | *Major* | **Create a jenkins file for yetus to processing GitHub PR**
+
+Add a new jenkins file for running pre commit check for GitHub PR.
+
+
+---
+
+* [HBASE-22007](https://issues.apache.org/jira/browse/HBASE-22007) | *Major* | **Add restoreSnapshot and cloneSnapshot with acl methods in AsyncAdmin**
+
+Add cloneSnapshot/restoreSnapshot with acl methods in AsyncAdmin.
+
+
+---
+
+* [HBASE-22123](https://issues.apache.org/jira/browse/HBASE-22123) | *Minor* | **REST gateway reports Insufficient permissions exceptions as 404 Not Found**
+
+When insufficient permissions, you now get:
+
+HTTP/1.1 403 Forbidden
+
+on the HTTP side, and in the message
+
+Forbidden
+org.apache.hadoop.hbase.security.AccessDeniedException: org.apache.hadoop.hbase.security.AccessDeniedException: Insufficient permissions for user ‘myuser',action: get, tableName:mytable, family:cf.
+at org.apache.ranger.authorization.hbase.RangerAuthorizationCoprocessor.authorizeAccess(RangerAuthorizationCoprocessor.java:547)
+and the rest of the ADE stack
+
+
+---
+
+* [HBASE-22100](https://issues.apache.org/jira/browse/HBASE-22100) | *Minor* | **False positive for error prone warnings in pre commit job**
+
+Now we will sort the javac WARNING/ERROR before generating diff in pre-commit so we can get a stable output for the error prone. The downside is that we just sort the output lexicographically so the line number will also be sorted lexicographically, which is a bit strange to human.
+
+
+---
+
+* [HBASE-22057](https://issues.apache.org/jira/browse/HBASE-22057) | *Major* | **Impose upper-bound on size of ZK ops sent in a single multi()**
+
+Exposes a new configuration property "zookeeper.multi.max.size" which dictates the maximum size of deletes that HBase will make to ZooKeeper in a single RPC. This property defaults to 1MB, which should fall beneath the default ZooKeeper limit of 2MB, controlled by "jute.maxbuffer".
+
+
+---
+
+* [HBASE-22052](https://issues.apache.org/jira/browse/HBASE-22052) | *Major* | **pom cleaning; filter out jersey-core in hadoop2 to match hadoop3 and remove redunant version specifications**
+
+<!-- markdown -->
+# HBASE 2.2.0 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | *Major* | **Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements**
+
+Moving IA.Public class LossyCounting to IA.Private.
+
+
+---
+
+* [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | *Major* | **Update hadoop check versions for hadoop3 in hbase-personality**
+
+Add hadoop 3.0.3, 3.1.1 3.1.2 in our hadoop check jobs.
+
+
+---
+
+* [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | *Major* | **Dump replication queue should show list of wal files ordered chronologically**
+
+The DumpReplicationQueues tool will now list replication queues sorted in chronological order.
+
+
+---
+
+* [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | *Minor* | **Formatting issues in administration section of book**
+
+Fixes a formatting issue in the administration section of the book, where listing indentation were a little bit off.
+
+
+---
+
+* [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | *Major* | **Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks**
+
+Now the default hadoop-two.version has been changed to 2.8.5, and all hadoop versions before 2.8.2(exclude) will not be supported any more.
+
+
+---
+
+* [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | *Trivial* | **Remove extra/useless +**
+
+Removed extra + in HRegion, HStore and LoadIncrementalHFiles for branch-2 and HRegion and HStore for branch-1.
+
+
+---
+
+* [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | *Trivial* | **Fix completebulkload usage instructions**
+
+Added completebulkload short name for BulkLoadHFilesTool to bin/hbase.
+
+
+---
+
+* [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | *Major* | **Upgrade com.yammer.metrics dependency**
+
+Updated metrics core from 3.2.1 to 3.2.6.
+
+
+---
+
+* [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | *Minor* | **Change rubocop configuration for method length**
+
+The rubocop definition for the maximum method length was set to 75.
+
+
+---
+
+* [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | *Minor* | **Fix Markdown for "Voting on Release Candidates" in book**
+
+Fixes the formatting of the "Voting on Release Candidates" to actually show the quote and code formatting of the RAT check.
+
+
+---
+
+* [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | *Minor* | **Change rubocop config for max line length of 100**
+
+The rubocop configuration in the hbase-shell module now allows a line length with 100 characters, instead of 80 as before. For everything before 2.1.5 this change introduces rubocop itself.
+
+
+---
+
+* [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | *Minor* | **Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS**
+
+This change allows the system and superusers to initiate compactions, even when a space quota violation policy disallows compactions from happening. The original intent behind disallowing of compactions was to prevent end-user compactions from creating undue I/O load, not disallowing \*any\* compaction in the system.
+
+
+---
+
+* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
+
+Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
+
+
+---
+
+* [HBASE-22155](https://issues.apache.org/jira/browse/HBASE-22155) | *Major* | **Move 2.2.0 on to hbase-thirdparty-2.2.0**
+
+ Updates libs used internally by hbase via hbase-thirdparty as follows:
+
+ gson 2.8.1 -\\\> 2.8.5
+ guava 22.0 -\\\> 27.1-jre
+ pb 3.5.1 -\\\> 3.7.0
+ netty 4.1.17 -\\\> 4.1.34
+ commons-collections4 4.1 -\\\> 4.3
+
+
+---
+
+* [HBASE-22178](https://issues.apache.org/jira/browse/HBASE-22178) | *Major* | **Introduce a createTableAsync with TableDescriptor method in Admin**
+
+Introduced
+
+Future\<Void\> createTableAsync(TableDescriptor);
+
+
+---
+
+* [HBASE-22108](https://issues.apache.org/jira/browse/HBASE-22108) | *Major* | **Avoid passing null in Admin methods**
+
+Introduced these methods:
+void move(byte[]);
+void move(byte[], ServerName);
+Future\<Void\> splitRegionAsync(byte[]);
+
+These methods are deprecated:
+void move(byte[], byte[])
+
+
+---
+
+* [HBASE-22152](https://issues.apache.org/jira/browse/HBASE-22152) | *Major* | **Create a jenkins file for yetus to processing GitHub PR**
+
+Add a new jenkins file for running pre commit check for GitHub PR.
+
+
+---
+
+* [HBASE-22007](https://issues.apache.org/jira/browse/HBASE-22007) | *Major* | **Add restoreSnapshot and cloneSnapshot with acl methods in AsyncAdmin**
+
+Add cloneSnapshot/restoreSnapshot with acl methods in AsyncAdmin.
+
+
+---
+
+* [HBASE-22123](https://issues.apache.org/jira/browse/HBASE-22123) | *Minor* | **REST gateway reports Insufficient permissions exceptions as 404 Not Found**
+
+When insufficient permissions, you now get:
+
+HTTP/1.1 403 Forbidden
+
+on the HTTP side, and in the message
+
+Forbidden
+org.apache.hadoop.hbase.security.AccessDeniedException: org.apache.hadoop.hbase.security.AccessDeniedException: Insufficient permissions for user ‘myuser',action: get, tableName:mytable, family:cf.
+at org.apache.ranger.authorization.hbase.RangerAuthorizationCoprocessor.authorizeAccess(RangerAuthorizationCoprocessor.java:547)
+and the rest of the ADE stack
+
+
+---
+
+* [HBASE-22100](https://issues.apache.org/jira/browse/HBASE-22100) | *Minor* | **False positive for error prone warnings in pre commit job**
+
+Now we will sort the javac WARNING/ERROR before generating diff in pre-commit so we can get a stable output for the error prone. The downside is that we just sort the output lexicographically so the line number will also be sorted lexicographically, which is a bit strange to human.
+
+
+---
+
+* [HBASE-22057](https://issues.apache.org/jira/browse/HBASE-22057) | *Major* | **Impose upper-bound on size of ZK ops sent in a single multi()**
+
+Exposes a new configuration property "zookeeper.multi.max.size" which dictates the maximum size of deletes that HBase will make to ZooKeeper in a single RPC. This property defaults to 1MB, which should fall beneath the default ZooKeeper limit of 2MB, controlled by "jute.maxbuffer".
+
+
+---
+
+* [HBASE-22052](https://issues.apache.org/jira/browse/HBASE-22052) | *Major* | **pom cleaning; filter out jersey-core in hadoop2 to match hadoop3 and remove redunant version specifications**
+
+<!-- markdown -->
+Fixed awkward dependency issue that prevented site building.
+
+#### note specific to HBase 2.1.4
+HBase 2.1.4 shipped with an early version of this fix that incorrectly altered the libraries included in our binary assembly for using Apache Hadoop 2.7 (the current build default Hadoop version for 2.1.z). For folks running out of the box against a Hadoop 2.7 cluster (or folks who skip the installation step of [replacing the bundled Hadoop libraries](http://hbase.apache.org/book.html#hadoop)) this will result in a failure at Region Server startup due to a missing class definition. e.g.:
+```
+2019-03-27 09:02:05,779 ERROR [main] regionserver.HRegionServer: Failed construction RegionServer
+java.lang.NoClassDefFoundError: org/apache/htrace/SamplerBuilder
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:644)
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:628)
+ at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
+ at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)
+ at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:93)
+ at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2701)
+ at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2683)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:372)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:171)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:356)
+ at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getRootDir(CommonFSUtils.java:362)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.isValidWALRootDir(CommonFSUtils.java:411)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getWALRootDir(CommonFSUtils.java:387)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.initializeFileSystem(HRegionServer.java:704)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.<init>(HRegionServer.java:613)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
+ at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
+ at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.constructRegionServer(HRegionServer.java:3029)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.start(HRegionServerCommandLine.java:63)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.run(HRegionServerCommandLine.java:87)
+ at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
+ at org.apache.hadoop.hbase.util.ServerCommandLine.doMain(ServerCommandLine.java:149)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.main(HRegionServer.java:3047)
+Caused by: java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
+ at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
+ at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
+ ... 26 more
+
+```
+
+Workaround via any _one_ of the following:
+* If you are running against a Hadoop cluster that is 2.8+, ensure you replace the Hadoop libaries in the default binary assembly with those for your version.
+* If you are running against a Hadoop cluster that is 2.8+, build the binary assembly from the source release while specifying your Hadoop version.
+* If you are running against a Hadoop cluster that is a supported 2.7 release, ensure the `hadoop` executable is in the `PATH` seen at Region Server startup and that you are not using the `HBASE_DISABLE_HADOOP_CLASSPATH_LOOKUP` bypass.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers via the HBASE_CLASSPATH environment variable.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers by copying it into the directory `${HBASE_HOME}/lib/client-facing-thirdparty/`.
+
+
+---
+
+* [HBASE-22065](https://issues.apache.org/jira/browse/HBASE-22065) | *Major* | **Add listTableDescriptors(List\<TableName\>) method in AsyncAdmin**
+
+Add a listTableDescriptors(List\<TableName\>) method in the AsyncAdmin interface, to align with the Admin interface.
+
+
+---
+
+* [HBASE-22040](https://issues.apache.org/jira/browse/HBASE-22040) | *Major* | **Add mergeRegionsAsync with a List of region names method in AsyncAdmin**
+
+Add a mergeRegionsAsync(byte[][], boolean) method in the AsyncAdmin interface.
+
+Instead of using assert, now we will throw IllegalArgumentException when you want to merge less than 2 regions at client side. And also, at master side, instead of using assert, now we will throw DoNotRetryIOException if you want merge more than 2 regions, since we only support merging two regions at once for now.
+
+
+---
+
+* [HBASE-22039](https://issues.apache.org/jira/browse/HBASE-22039) | *Major* | **Should add the synchronous parameter for the XXXSwitch method in AsyncAdmin**
+
+Add drainXXX parameter for balancerSwitch/splitSwitch/mergeSwitch methods in the AsyncAdmin interface, which has the same meaning with the synchronous parameter for these methods in the Admin interface.
+
+
+---
+
+* [HBASE-21810](https://issues.apache.org/jira/browse/HBASE-21810) | *Major* | **bulkload support set hfile compression on client**
+
+bulkload (HFileOutputFormat2) support config the compression on client ,you can set the job configuration "hbase.mapreduce.hfileoutputformat.compression" override the auto-detection of the target table's compression
+
+
+---
+
+* [HBASE-22000](https://issues.apache.org/jira/browse/HBASE-22000) | *Major* | **Deprecated isTableAvailable with splitKeys**
+
+Deprecated AsyncTable.isTableAvailable(TableName, byte[][]).
+
+
+---
+
+* [HBASE-21871](https://issues.apache.org/jira/browse/HBASE-21871) | *Major* | **Support to specify a peer table name in VerifyReplication tool**
+
+After HBASE-21871, we can specify a peer table name with --peerTableName in VerifyReplication tool like the following:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable 5 TestTable
+
+In addition, we can compare any 2 tables in any remote clusters with specifying both peerId and --peerTableName.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable zk1,zk2,zk3:2181/hbase TestTable
+
+
+---
+
+* [HBASE-15728](https://issues.apache.org/jira/browse/HBASE-15728) | *Major* | **Add remaining per-table region / store / flush / compaction related metrics**
+
+Adds below flush, split, and compaction metrics
+
+ + // split related metrics
+ + private MutableFastCounter splitRequest;
+ + private MutableFastCounter splitSuccess;
+ + private MetricHistogram splitTimeHisto;
+ +
+ + // flush related metrics
+ + private MetricHistogram flushTimeHisto;
+ + private MetricHistogram flushMemstoreSizeHisto;
+ + private MetricHistogram flushOutputSizeHisto;
+ + private MutableFastCounter flushedMemstoreBytes;
+ + private MutableFastCounter flushedOutputBytes;
+ +
+ + // compaction related metrics
+ + private MetricHistogram compactionTimeHisto;
+ + private MetricHistogram compactionInputFileCountHisto;
+ + private MetricHistogram compactionInputSizeHisto;
+ + private MetricHistogram compactionOutputFileCountHisto;
+ + private MetricHistogram compactionOutputSizeHisto;
+ + private MutableFastCounter compactedInputBytes;
+ + private MutableFastCounter compactedOutputBytes;
+ +
+ + private MetricHistogram majorCompactionTimeHisto;
+ + private MetricHistogram majorCompactionInputFileCountHisto;
+ + private MetricHistogram majorCompactionInputSizeHisto;
+ + private MetricHistogram majorCompactionOutputFileCountHisto;
+ + private MetricHistogram majorCompactionOutputSizeHisto;
+ + private MutableFastCounter majorCompactedInputBytes;
+ + private MutableFastCounter majorCompactedOutputBytes;
+
+
+---
+
+* [HBASE-20886](https://issues.apache.org/jira/browse/HBASE-20886) | *Critical* | **[Auth] Support keytab login in hbase client**
+
+From 2.2.0, hbase supports client login via keytab. To use this feature, client should specify \`hbase.client.keytab.file\` and \`hbase.client.keytab.principal\` in hbase-site.xml, then the connection will contain the needed credentials which be renewed periodically to communicate with kerberized hbase cluster.
+
+
+---
+
+* [HBASE-21410](https://issues.apache.org/jira/browse/HBASE-21410) | *Major* | **A helper page that help find all problematic regions and procedures**
+
+After HBASE-21410, we add a helper page to Master UI. This helper page is mainly to help HBase operator quickly found all regions and pids that are get stuck.
+There are 2 entries to get in this page.
+One is showing in the Regions in Transition section, it made "num region(s) in transition" a link that you can click and check all regions in transition and their related procedure IDs.
+The other one is showing in the table details section, it made the number of CLOSING or OPENING regions a link, which you can click and check regions and related procedure IDs of CLOSING or OPENING regions of a certain table.
+In this helper page, not only you can see all regions and related procedures, there are 2 buttons at the top which will show these regions or procedure IDs in text format. This is mainly aim to help operator to easily copy and paste all problematic procedure IDs and encoded region names to HBCK2's command line, by which we HBase operator can bypass these procedures or assign these regions.
+
+
+---
+
+* [HBASE-21588](https://issues.apache.org/jira/browse/HBASE-21588) | *Major* | **Procedure v2 wal splitting implementation**
+
+After HBASE-21588, we introduce a new way to do WAL splitting coordination by procedure framework. This can simplify the process of WAL splitting and no need to connect zookeeper any more.
+During ServerCrashProcedure, it will create a SplitWALProcedure for each WAL that need to split. Then each SplitWALProcedure will spawn a SplitWALRemoteProcedure to send the request to regionserver.
+At the RegionServer side, whole process is handled by SplitWALCallable. It split the WAL and return the result to master.
+According to my test, this patch has a better performance as the number of WALs that need to split increase. And it can relieve the pressure on zookeeper.
+
+
+---
+
+* [HBASE-20734](https://issues.apache.org/jira/browse/HBASE-20734) | *Major* | **Colocate recovered edits directory with hbase.wal.dir**
+
+Previously the recovered.edits directory was under the root directory. This JIRA moves the recovered.edits directory to be under the hbase.wal.dir if set. It also adds a check for any recovered.edits found under the root directory for backwards compatibility. This gives improvements when a faster media(like SSD) or more local FileSystem is used for the hbase.wal.dir than the root dir.
+
+
+---
+
+* [HBASE-20401](https://issues.apache.org/jira/browse/HBASE-20401) | *Minor* | **Make \`MAX\_WAIT\` and \`waitIfNotFinished\` in CleanerContext configurable**
+
+When oldwals (and hfile) cleaner cleans stale wals (and hfiles), it will periodically check and wait the clean results from filesystem, the total wait time will be no more than a max time.
+
+The periodically wait and check configurations are hbase.oldwals.cleaner.thread.check.interval.msec (default is 500 ms) and hbase.regionserver.hfilecleaner.thread.check.interval.msec (default is 1000 ms).
+
+Meanwhile, The max time configurations are hbase.oldwals.cleaner.thread.timeout.msec and hbase.regionserver.hfilecleaner.thread.timeout.msec, they are set to 60 seconds by default.
+
+All support dynamic configuration.
+
+e.g. in the oldwals cleaning scenario, one may consider tuning hbase.oldwals.cleaner.thread.timeout.msec and hbase.oldwals.cleaner.thread.check.interval.msec
+
+1. While deleting a oldwal never complete (strange but possible), then delete file task needs to wait for a max of 60 seconds. Here, 60 seconds might be too long, or the opposite way is to increase more than 60 seconds in the use cases of slow file delete.
+2. The check and wait of a file delete is set to default in the period of 500 milliseconds, one might want to tune this checking period to a short interval to check more frequently or to a longer interval to avoid checking too often to manage their delete file task checking period (the longer interval may be use to avoid checking too fast while using a high latency storage).
+
+
+---
+
+* [HBASE-21481](https://issues.apache.org/jira/browse/HBASE-21481) | *Major* | **[acl] Superuser's permissions should not be granted or revoked by any non-su global admin**
+
+HBASE-21481 improves the quality of access control, by strengthening the protection of super users's privileges.
+
+
+---
+
+* [HBASE-21082](https://issues.apache.org/jira/browse/HBASE-21082) | *Critical* | **Reimplement assign/unassign related procedure metrics**
+
+Now we have four types of RIT procedure metrics, assign, unassign, move, reopen. The meaning of assign/unassign is changed, as we will not increase the unassign metric and then the assign metric when moving a region.
+Also introduced two new procedure metrics, open and close, which are used to track the open/close region calls to region server. We may send open/close multiple times to finish a RIT since we may retry multiple times.
+
+
+---
+
+* [HBASE-20724](https://issues.apache.org/jira/browse/HBASE-20724) | *Critical* | **Sometimes some compacted storefiles are still opened after region failover**
+
+Problem: This is an old problem since HBASE-2231. The compaction event marker was only writed to WAL. But after flush, the WAL may be archived, which means an useful compaction event marker be deleted, too. So the compacted store files cannot be archived when region open and replay WAL.
+
+Solution: After this jira, the compaction event tracker will be writed to HFile. When region open and load store files, read the compaction evnet tracker from HFile and archive the compacted store files which still exist.
+
+
+---
+
+* [HBASE-21820](https://issues.apache.org/jira/browse/HBASE-21820) | *Major* | **Implement CLUSTER quota scope**
+
+HBase contains two quota scopes: MACHINE and CLUSTER. Before this patch, set quota operations did not expose scope option to client api and use MACHINE as default, CLUSTER scope can not be set and used.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+
+This issue implements CLUSTER scope in a simple way: For user, namespace, user over namespace quota, use [ClusterLimit / RSNum] as machine limit. For table and user over table quota, use [ClusterLimit / TotalTableRegionNum \* MachineTableRegionNum] as machine limit.
+After this patch, user can set CLUSTER scope quota, but MACHINE is still default if user ignore scope.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> MACHINE
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> CLUSTER
+
+
+---
+
+* [HBASE-21057](https://issues.apache.org/jira/browse/HBASE-21057) | *Minor* | **upgrade to latest spotbugs**
+
+Change spotbugs version to 3.1.11.
+
+
+---
+
+* [HBASE-21922](https://issues.apache.org/jira/browse/HBASE-21922) | *Major* | **BloomContext#sanityCheck may failed when use ROWPREFIX\_DELIMITED bloom filter**
+
+Remove bloom filter type ROWPREFIX\_DELIMITED. May add it back when find a better solution.
+
+
+---
+
+* [HBASE-21783](https://issues.apache.org/jira/browse/HBASE-21783) | *Major* | **Support exceed user/table/ns throttle quota if region server has available quota**
+
+Support enable or disable exceed throttle quota. Exceed throttle quota means, user can over consume user/namespace/table quota if region server has additional available quota because other users don't consume at the same time.
+Use the following shell commands to enable/disable exceed throttle quota: enable\_exceed\_throttle\_quota
+disable\_exceed\_throttle\_quota
+There are two limits when enable exceed throttle quota:
+1. Must set at least one read and one write region server throttle quota;
+2. All region server throttle quotas must be in seconds time unit. Because once previous requests exceed their quota and consume region server quota, quota in other time units may be refilled in a long time, this may affect later requests.
+
+
+---
+
+* [HBASE-20587](https://issues.apache.org/jira/browse/HBASE-20587) | *Major* | **Replace Jackson with shaded thirdparty gson**
+
+Remove jackson dependencies from most hbase modules except hbase-rest, use shaded gson instead. The output json will be a bit different since jackson can use getter/setter, but gson will always use the fields.
+
+
+---
+
+* [HBASE-21928](https://issues.apache.org/jira/browse/HBASE-21928) | *Major* | **Deprecated HConstants.META\_QOS**
+
+Mark HConstants.META\_QOS as deprecated. It is for internal use only, which is the highest priority. You should not try to set a priority greater than or equal to this value, although it is no harm but also useless.
+
+
+---
+
+* [HBASE-17942](https://issues.apache.org/jira/browse/HBASE-17942) | *Major* | **Disable region splits and merges per table**
+
+This patch adds the ability to disable split and/or merge for a table (By default, split and merge are enabled for a table).
+
+
+---
+
+* [HBASE-21636](https://issues.apache.org/jira/browse/HBASE-21636) | *Major* | **Enhance the shell scan command to support missing scanner specifications like ReadType, IsolationLevel etc.**
+
+Allows shell to set Scan options previously not exposed. See additions as part of the scan help by typing following hbase shell:
+
+hbase\> help 'scan'
+
+
+---
+
+* [HBASE-21201](https://issues.apache.org/jira/browse/HBASE-21201) | *Major* | **Support to run VerifyReplication MR tool without peerid**
+
+We can specify peerQuorumAddress instead of peerId in VerifyReplication tool. So it no longer requires peerId to be setup when using this tool.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication zk1,zk2,zk3:2181/hbase testTable
+
+
+---
+
+* [HBASE-21838](https://issues.apache.org/jira/browse/HBASE-21838) | *Major* | **Create a special ReplicationEndpoint just for verifying the WAL entries are fine**
+
+Introduce a VerifyWALEntriesReplicationEndpoint which replicates nothing but only verifies if all the cells are valid.
+It can be used to capture bugs for writing WAL, as most times we will not read the WALs again after writing it if there are no region server crashes.
+
+
+---
+
+* [HBASE-21727](https://issues.apache.org/jira/browse/HBASE-21727) | *Minor* | **Simplify documentation around client timeout**
+
+Deprecated HBaseConfiguration#getInt(Configuration, String, String, int) method and removed it from 3.0.0 version.
+
+
+---
+
+* [HBASE-21764](https://issues.apache.org/jira/browse/HBASE-21764) | *Major* | **Size of in-memory compaction thread pool should be configurable**
+
+Introduced an new config key in this issue: hbase.regionserver.inmemory.compaction.pool.size. the default value would be 10. you can configure this to set the pool size of in-memory compaction pool. Note that all memstores in one region server will share the same pool, so if you have many regions in one region server, you need to set this larger to compact faster for better read performance.
+
+
+---
+
+* [HBASE-21684](https://issues.apache.org/jira/browse/HBASE-21684) | *Major* | **Throw DNRIOE when connection or rpc client is closed**
+
+Make StoppedRpcClientException extend DoNotRetryIOException.
+
+
+---
+
+* [HBASE-21739](https://issues.apache.org/jira/browse/HBASE-21739) | *Major* | **Move grant/revoke from regionserver to master**
+
+To implement user permission control in Precedure V2, move grant and revoke method from AccessController to master firstly.
+Mark AccessController#grant and AccessController#revoke as deprecated and please use Admin#grant and Admin#revoke instead.
+
+
+---
+
+* [HBASE-21791](https://issues.apache.org/jira/browse/HBASE-21791) | *Blocker* | **Upgrade thrift dependency to 0.12.0**
+
+IMPORTANT: Due to security issues, all users who use hbase thrift should avoid using releases which do not have this fix.
+
+The effect releases are:
+2.1.x: 2.1.2 and below
+2.0.x: 2.0.4 and below
+1.x: 1.4.x and below
+
+If you are using the effect releases above, please consider upgrading to a newer release ASAP.
+
+
+---
+
+* [HBASE-21792](https://issues.apache.org/jira/browse/HBASE-21792) | *Major* | **Mark HTableMultiplexer as deprecated and remove it in 3.0.0**
+
+HTableMultiplexer exposes the implementation class, and it is incomplete, so we mark it as deprecated and remove it in 3.0.0 release.
+
+There is no direct replacement for HTableMultiplexer, please use BufferedMutator if you want to batch mutations to a table.
+
+
+---
+
+* [HBASE-21782](https://issues.apache.org/jira/browse/HBASE-21782) | *Major* | **LoadIncrementalHFiles should not be IA.Public**
+
+Introduce a BulkLoadHFiles interface which is marked as IA.Public, for doing bulk load programmatically.
+Introduce a BulkLoadHFilesTool which extends BulkLoadHFiles, and is marked as IA.LimitedPrivate(TOOLS), for using from command line.
+The old LoadIncrementalHFiles is deprecated and will be removed in 3.0.0.
+
+
+---
+
+* [HBASE-21762](https://issues.apache.org/jira/browse/HBASE-21762) | *Major* | **Move some methods in ClusterConnection to Connection**
+
+Move the two getHbck method from ClusterConnection to Connection, and mark the methods as IA.LimitedPrivate(HBCK), as ClusterConnection is IA.Private and should not be depended by HBCK2.
+
+Add a clearRegionLocationCache method in Connection to clear the region location cache for all the tables. As in RegionLocator, most of the methods have a 'reload' parameter, which implicitly tells user that we have a region location cache, so adding a method to clear the cache is fine.
+
+
+---
+
+* [HBASE-21713](https://issues.apache.org/jira/browse/HBASE-21713) | *Major* | **Support set region server throttle quota**
+
+Support set region server rpc throttle quota which represents the read/write ability of region servers and throttles when region server's total requests exceeding the limit.
+
+Use the following shell command to set RS quota:
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', THROTTLE\_TYPE =\> WRITE, LIMIT =\> '20000req/sec'
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', LIMIT =\> NONE
+"all" represents the throttle quota of all region servers and setting specified region server quota isn't supported currently.
+
+
+---
+
+* [HBASE-21689](https://issues.apache.org/jira/browse/HBASE-21689) | *Minor* | **Make table/namespace specific current quota info available in shell(describe\_namespace & describe)**
+
+In shell commands "describe\_namespace" and "describe", which are used to see the descriptors of the namespaces and tables respectively, quotas set on that particular namespace/table will also be printed along.
+
+
+---
+
+* [HBASE-17370](https://issues.apache.org/jira/browse/HBASE-17370) | *Major* | **Fix or provide shell scripts to drain and decommission region server**
+
+Adds shell support for the following:
+- List decommissioned/draining region servers
+- Decommission a list of region servers, optionally offload corresponding regions
+- Recommission a region server, optionally load a list of passed regions
+
+
+---
+
+* [HBASE-21734](https://issues.apache.org/jira/browse/HBASE-21734) | *Major* | **Some optimization in FilterListWithOR**
+
+After HBASE-21620, the filterListWithOR has been a bit slow because we need to merge each sub-filter's RC , while before HBASE-21620, we will skip many RC merging, but the logic was wrong. So here we choose another way to optimaze the performance: removing the KeyValueUtil#toNewKeyCell.
+Anoop Sam John suggested that the KeyValueUtil#toNewKeyCell can save some GC before because if we copy key part of cell into a single byte[], then the block the cell refering won't be refered by the filter list any more, the upper layer can GC the data block quickly. while after HBASE-21620, we will update the prevCellList for every encountered cell now, so the lifecycle of cell in prevCellList for FilterList will be quite shorter. so just use the cell ref for saving cpu.
+BTW, we removed all the arrays streams usage in filter list, because it's also quite time-consuming in our test.
+
+
+---
+
+* [HBASE-21738](https://issues.apache.org/jira/browse/HBASE-21738) | *Critical* | **Remove all the CSLM#size operation in our memstore because it's an quite time consuming.**
+
+We found the memstore snapshotting would cost much time because of calling the time-consuming ConcurrentSkipListMap#Size, it would make the p999 latency spike happen. So in this issue, we remove all ConcurrentSkipListMap#size in memstore by counting the cellsCount in MemstoreSizeing. As the issue described, the p999 latency spike was mitigated.
+
+
+---
+
+* [HBASE-21034](https://issues.apache.org/jira/browse/HBASE-21034) | *Major* | **Add new throttle type: read/write capacity unit**
+
+Provides a new throttle type: capacity unit. One read/write/request capacity unit represents that read/write/read+write up to 1K data. If data size is more than 1K, then consume additional capacity units.
+
+Use shell command to set capacity unit(CU):
+set\_quota TYPE =\> THROTTLE, THROTTLE\_TYPE =\> WRITE, USER =\> 'u1', LIMIT =\> '10CU/sec'
+
+Use the "hbase.quota.read.capacity.unit" property to set the data size of one read capacity unit in bytes, the default value is 1K. Use the "hbase.quota.write.capacity.unit" property to set the data size of one write capacity unit in bytes, the default value is 1K.
+
+
+---
+
+* [HBASE-21595](https://issues.apache.org/jira/browse/HBASE-21595) | *Minor* | **Print thread's information and stack traces when RS is aborting forcibly**
+
+Does thread dump on stdout on abort.
+
+
+---
+
+* [HBASE-21732](https://issues.apache.org/jira/browse/HBASE-21732) | *Critical* | **Should call toUpperCase before using Enum.valueOf in some methods for ColumnFamilyDescriptor**
+
+Now all the Enum configs in ColumnFamilyDescriptor can accept lower case config value.
+
+
+---
+
+* [HBASE-21712](https://issues.apache.org/jira/browse/HBASE-21712) | *Minor* | **Make submit-patch.py python3 compatible**
+
+Python3 support was added to dev-support/submit-patch.py. To install newly required dependencies run \`pip install -r dev-support/python-requirements.txt\` command.
+
+
+---
+
+* [HBASE-21657](https://issues.apache.org/jira/browse/HBASE-21657) | *Major* | **PrivateCellUtil#estimatedSerializedSizeOf has been the bottleneck in 100% scan case.**
+
+In HBASE-21657, I simplified the path of estimatedSerialiedSize() & estimatedSerialiedSizeOfCell() by moving the general getSerializedSize()
+and heapSize() from ExtendedCell to Cell interface. The patch also included some other improvments:
+
+1. For 99% of case, our cells has no tags, so let the HFileScannerImpl just return the NoTagsByteBufferKeyValue if no tags, which means we can save
+ lots of cpu time when sending no tags cell to rpc because can just return the length instead of getting the serialize size by caculating offset/length
+ of each fields(row/cf/cq..)
+2. Move the subclass's getSerializedSize implementation from ExtendedCell to their own class, which mean we did not need to call ExtendedCell's
+ getSerialiedSize() firstly, then forward to subclass's getSerializedSize(withTags).
+3. Give a estimated result arraylist size for avoiding the frequent list extension when in a big scan, now we estimate the array size as min(scan.rows, 512).
+ it's also help a lot.
+
+We gain almost ~40% throughput improvement in 100% scan case for branch-2 (cacheHitRatio~100%)[1], it's a good thing. While it's a incompatible change in
+some case, such as if the upstream user implemented their own Cells, although it's rare but can happen, then their compile will be error.
+
+
+---
+
+* [HBASE-21647](https://issues.apache.org/jira/browse/HBASE-21647) | *Major* | **Add status track for splitting WAL tasks**
+
+Adds task monitor that shows ServerCrashProcedure progress in UI.
+
+
+---
+
+* [HBASE-21652](https://issues.apache.org/jira/browse/HBASE-21652) | *Major* | **Refactor ThriftServer making thrift2 server inherited from thrift1 server**
+
+Before this issue, thrift1 server and thrift2 server are totally different servers. If a new feature is added to thrift1 server, thrfit2 server have to make the same change to support it(e.g. authorization). After this issue, thrift2 server is inherited from thrift1, thrift2 server now have all the features thrift1 server has(e.g http support, which thrift2 server doesn't have before). The way to start thrift1 or thrift2 server remain the same after this issue.
+
+
+---
+
+* [HBASE-21661](https://issues.apache.org/jira/browse/HBASE-21661) | *Major* | **Provide Thrift2 implementation of Table/Admin**
+
+ThriftAdmin/ThriftTable are implemented based on Thrift2. With ThriftAdmin/ThriftTable, People can use thrift2 protocol just like HTable/HBaseAdmin.
+Example of using ThriftConnection
+Configuration conf = HBaseConfiguration.create();
+conf.set(ClusterConnection.HBASE\_CLIENT\_CONNECTION\_IMPL,ThriftConnection.class.getName());
+Connection conn = ConnectionFactory.createConnection(conf);
+Table table = conn.getTable(tablename)
+It is just like a normal Connection, similar use experience with the default ConnectionImplementation
+
+
+---
+
+* [HBASE-21618](https://issues.apache.org/jira/browse/HBASE-21618) | *Critical* | **Scan with the same startRow(inclusive=true) and stopRow(inclusive=false) returns one result**
+
+There was a bug when scan with the same startRow(inclusive=true) and stopRow(inclusive=false). The old incorrect behavior is return one result. After this fix, the new correct behavior is return nothing.
+
+
+---
+
+* [HBASE-21159](https://issues.apache.org/jira/browse/HBASE-21159) | *Major* | **Add shell command to switch throttle on or off**
+
+Support enable or disable rpc throttle when hbase quota is enabled. If hbase quota is enabled, rpc throttle is enabled by default. When disable rpc throttle, HBase will not throttle any request. Use the following commands to switch rpc throttle : enable\_rpc\_throttle / disable\_rpc\_throttle.
+
+
+---
+
+* [HBASE-21659](https://issues.apache.org/jira/browse/HBASE-21659) | *Minor* | **Avoid to load duplicate coprocessors in system config and table descriptor**
+
+Add a new configuration "hbase.skip.load.duplicate.table.coprocessor". The default value is false to keep compatible with the old behavior. Config it true to skip load duplicate table coprocessor.
+
+
+---
+
+* [HBASE-21650](https://issues.apache.org/jira/browse/HBASE-21650) | *Major* | **Add DDL operation and some other miscellaneous to thrift2**
+
+Added DDL operations and some other structure definition to thrift2. Methods added:
+create/modify/addColumnFamily/deleteColumnFamily/modifyColumnFamily/enable/disable/truncate/delete table
+create/modify/delete namespace
+get(list)TableDescriptor(s)/get(list)NamespaceDescirptor(s)
+tableExists/isTableEnabled/isTableDisabled/isTableAvailabe
+And some class definitions along with those methods
+
+
+---
+
+* [HBASE-21643](https://issues.apache.org/jira/browse/HBASE-21643) | *Major* | **Introduce two new region coprocessor method and deprecated postMutationBeforeWAL**
+
+Deprecated region coprocessor postMutationBeforeWAL and introduce two new region coprocessor postIncrementBeforeWAL and postAppendBeforeWAL instead.
+
+
+---
+
+* [HBASE-21635](https://issues.apache.org/jira/browse/HBASE-21635) | *Major* | **Use maven enforcer to ban imports from illegal packages**
+
+Use de.skuzzle.enforcer.restrict-imports-enforcer-rule extension for maven enforcer plugin to ban illegal imports at compile time. Now if you use illegal imports, for example, import com.google.common.\*, there will be a compile error, instead of a checkstyle warning.
+
+
+---
+
+* [HBASE-21401](https://issues.apache.org/jira/browse/HBASE-21401) | *Critical* | **Sanity check when constructing the KeyValue**
+
+Add a sanity check when constructing KeyValue from a byte[]. we use the constructor when we're reading kv from socket or HFIle or WAL(replication). the santiy check isn't designed for discovering the bits corruption in network transferring or disk IO. It is designed to detect bugs inside HBase in advance. and HBASE-21459 indicated that there's extremely small performance loss for diff kinds of keyvalue.
+
+
+---
+
+* [HBASE-21554](https://issues.apache.org/jira/browse/HBASE-21554) | *Minor* | **Show replication endpoint classname for replication peer on master web UI**
+
+The replication UI on master will show the replication endpoint classname.
+
+
+---
+
+* [HBASE-21549](https://issues.apache.org/jira/browse/HBASE-21549) | *Major* | **Add shell command for serial replication peer**
+
+Add a SERIAL flag for add\_peer command to identifiy whether or not the replication peer is a serial replication peer. The default serial flag is false.
+
+
+---
+
+* [HBASE-21453](https://issues.apache.org/jira/browse/HBASE-21453) | *Major* | **Convert ReadOnlyZKClient to DEBUG instead of INFO**
+
+Log level of ReadOnlyZKClient moved to debug.
+
+
+---
+
+* [HBASE-21283](https://issues.apache.org/jira/browse/HBASE-21283) | *Minor* | **Add new shell command 'rit' for listing regions in transition**
+
+<!-- markdown -->
+
+The HBase `shell` now includes a command to list regions currently in transition.
+
+```
+HBase Shell
+Use "help" to get list of supported commands.
+Use "exit" to quit this interactive shell.
+Version 1.5.0-SNAPSHOT, r9bb6d2fa8b760f16cd046657240ebd4ad91cb6de, Mon Oct 8 21:05:50 UTC 2018
+
+hbase(main):001:0> help 'rit'
+List all regions in transition.
+Examples:
+ hbase> rit
+
+hbase(main):002:0> create ...
+0 row(s) in 2.5150 seconds
+=> Hbase::Table - IntegrationTestBigLinkedList
+
+hbase(main):003:0> rit
+0 row(s) in 0.0340 seconds
+
+hbase(main):004:0> unassign '56f0c38c81ae453d19906ce156a2d6a1'
+0 row(s) in 0.0540 seconds
+
+hbase(main):005:0> rit
+IntegrationTestBigLinkedList,L\xCC\xCC\xCC\xCC\xCC\xCC\xCB,1539117183224.56f0c38c81ae453d19906ce156a2d6a1. state=PENDING_CLOSE, ts=Tue Oct 09 20:33:34 UTC 2018 (0s ago), server=null
+1 row(s) in 0.0170 seconds
+```
+
+
+---
+
+* [HBASE-21567](https://issues.apache.org/jira/browse/HBASE-21567) | *Major* | **Allow overriding configs starting up the shell**
+
+Allow passing of -Dkey=value option to shell to override hbase-\* configuration: e.g.:
+
+$ ./bin/hbase shell -Dhbase.zookeeper.quorum=ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org -Draining=false
+...
+hbase(main):001:0\> @shell.hbase.configuration.get("hbase.zookeeper.quorum")
+=\> "ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org"
+hbase(main):002:0\> @shell.hbase.configuration.get("raining")
+=\> "false"
+
+
+---
+
+* [HBASE-21560](https://issues.apache.org/jira/browse/HBASE-21560) | *Major* | **Return a new TableDescriptor for MasterObserver#preModifyTable to allow coprocessor modify the TableDescriptor**
+
+Incompatible change. Allow MasterObserver#preModifyTable to return a new TableDescriptor. And master will use this returned TableDescriptor to modify table.
+
+
+---
+
+* [HBASE-21551](https://issues.apache.org/jira/browse/HBASE-21551) | *Blocker* | **Memory leak when use scan with STREAM at server side**
+
+<!-- markdown -->
+### Summary
+HBase clusters will experience Region Server failures due to out of memory errors due to a leak given any of the following:
+
+* User initiates Scan operations set to use the STREAM reading type
+* User initiates Scan operations set to use the default reading type that read more than 4 * the block size of column families involved in the scan (e.g. by default 4*64KiB)
+* Compactions run
+
+### Root cause
+
+When there are long running scans the Region Server process attempts to optimize access by using a different API geared towards sequential access. Due to an error in HBASE-20704 for HBase 2.0+ the Region Server fails to release related resources when those scans finish. That same optimization path is always used for the HBase internal file compaction process.
+
+### Workaround
+
+Impact for this error can be minimized by setting the config value “hbase.storescanner.pread.max.bytes” to MAX_INT to avoid the optimization for default user scans. Clients should also be checked to ensure they do not pass the STREAM read type to the Scan API. This will have a severe impact on performance for long scans.
+
+Compactions always use this sequential optimized reading mechanism so downstream users will need to periodically restart Region Server roles after compactions have happened.
+
+
+---
+
+* [HBASE-21550](https://issues.apache.org/jira/browse/HBASE-21550) | *Major* | **Add a new method preCreateTableRegionInfos for MasterObserver which allows CPs to modify the TableDescriptor**
+
+Add a new method preCreateTableRegionInfos for MasterObserver, which will be called before creating region infos for the given table, before the preCreateTable method. It allows you to return a new TableDescritor to override the original one. Returns null or throws exception will stop the creation.
+
+
+---
+
+* [HBASE-21492](https://issues.apache.org/jira/browse/HBASE-21492) | *Critical* | **CellCodec Written To WAL Before It's Verified**
+
+After HBASE-21492 the return type of WALCellCodec#getWALCellCodecClass has been changed from String to Class
+
+
+---
+
+* [HBASE-21387](https://issues.apache.org/jira/browse/HBASE-21387) | *Major* | **Race condition surrounding in progress snapshot handling in snapshot cache leads to loss of snapshot files**
+
+To prevent race condition between in progress snapshot (performed by TakeSnapshotHandler) and HFileCleaner which results in data loss, this JIRA introduced mutual exclusion between taking snapshot and running HFileCleaner. That is, at any given moment, either some snapshot can be taken or, HFileCleaner checks hfiles which are not referenced, but not both can be running.
+
+
+---
+
+* [HBASE-21452](https://issues.apache.org/jira/browse/HBASE-21452) | *Major* | **Illegal character in hbase counters group name**
+
+Changes group name of hbase metrics from "HBase Counters" to "HBaseCounters".
+
+
+---
+
+* [HBASE-21443](https://issues.apache.org/jira/browse/HBASE-21443) | *Major* | **[hbase-connectors] Purge hbase-\* modules from core now they've been moved to hbase-connectors**
+
+Parent issue moved hbase-spark\* modules to hbase-connectors. This issue removes hbase-spark\* modules from hbase core repo.
+
+
+---
+
+* [HBASE-21430](https://issues.apache.org/jira/browse/HBASE-21430) | *Major* | **[hbase-connectors] Move hbase-spark\* modules to hbase-connectors repo**
+
+hbase-spark\* modules have been cloned to https://github.com/apache/hbase-connectors All spark connector dev is to happen in that repo from here on out.
+
+Let me file a subtask to remove hbase-spark\* modules from hbase core.
+
+
+---
+
+* [HBASE-21417](https://issues.apache.org/jira/browse/HBASE-21417) | *Critical* | **Pre commit build is broken due to surefire plugin crashes**
+
+Add -Djdk.net.URLClassPath.disableClassPathURLCheck=true when executing surefire plugin.
+
+
+---
+
+* [HBASE-21191](https://issues.apache.org/jira/browse/HBASE-21191) | *Major* | **Add a holding-pattern if no assign for meta or namespace (Can happen if masterprocwals have been cleared).**
+
+Puts master startup into holding pattern if meta is not assigned (previous it would exit). To make progress again, operator needs to inject an assign (Caveats and instruction can be found in HBASE-21035).
+
+
+---
+
+* [HBASE-21322](https://issues.apache.org/jira/browse/HBASE-21322) | *Critical* | **Add a scheduleServerCrashProcedure() API to HbckService**
+
+Adds scheduleServerCrashProcedure to the HbckService.
+
+
+---
+
+* [HBASE-21325](https://issues.apache.org/jira/browse/HBASE-21325) | *Major* | **Force to terminate regionserver when abort hang in somewhere**
+
+Add two new config hbase.regionserver.abort.timeout and hbase.regionserver.abort.timeout.task. If regionserver abort timeout, it will schedule an abort timeout task to run. The default abort task is SystemExitWhenAbortTimeout, which will force to terminate region server when abort timeout. And you can config a special abort timeout task by hbase.regionserver.abort.timeout.task.
+
+
+---
+
+* [HBASE-21215](https://issues.apache.org/jira/browse/HBASE-21215) | *Major* | **Figure how to invoke hbck2; make it easy to find**
+
+Adds to bin/hbase means of invoking hbck2. Pass the new '-j' option on the 'hbck' command with a value of the full path to the HBCK2.jar.
+
+E.g:
+
+$ ./bin/hbase hbck -j ~/checkouts/hbase-operator-tools/hbase-hbck2/target/hbase-hbck2-1.0.0-SNAPSHOT.jar setTableState x ENABLED
+
+
+---
+
+* [HBASE-21372](https://issues.apache.org/jira/browse/HBASE-21372) | *Major* | **Set hbase.assignment.maximum.attempts to Long.MAX**
+
+Retry assigns 'forever' (or until an intervention such as a ServerCrashProcedure).
+
+Previous retry was a maximum of ten times but on failure, handling was an indeterminate.
+
+
+---
+
+* [HBASE-21338](https://issues.apache.org/jira/browse/HBASE-21338) | *Major* | **[balancer] If balancer is an ill-fit for cluster size, it gives little indication**
+
+The description claims the balancer not dynamically configurable but this is an error; it is http://hbase.apache.org/book.html#dyn\_config
+
+Also, if balancer is seen to be cutting out too soon, try setting "hbase.master.balancer.stochastic.runMaxSteps" to true.
+
+Adds cleaner logging around balancer start.
+
+
+---
+
+* [HBASE-21073](https://issues.apache.org/jira/browse/HBASE-21073) | *Major* | **"Maintenance mode" master**
+
+ Instead of being an ephemeral state set by hbck, maintenance mode is now
+ an explicit toggle set by either configuration property or environment
+ variable. In maintenance mode, master will host system tables and not
+ assign any user-space tables to RSs. This gives operators the ability to
+ affect repairs to meta table with fewer moving parts.
+
+
+---
+
+* [HBASE-21335](https://issues.apache.org/jira/browse/HBASE-21335) | *Critical* | **Change the default wait time of HBCK2 tool**
+
+Changed waitTime parameter to lockWait on bypass. Changed default waitTime from 0 -- i.e. wait for ever -- to 1ms so if lock is held, we'll go past it and if override enforce bypass.
+
+
+---
+
+* [HBASE-21291](https://issues.apache.org/jira/browse/HBASE-21291) | *Major* | **Add a test for bypassing stuck state-machine procedures**
+
+bypass will now throw an Exception if passed a lockWait \<= 0; i.e bypass will prevent an operator getting stuck on an entity lock waiting forever (lockWait == 0)
+
+
+---
+
+* [HBASE-21320](https://issues.apache.org/jira/browse/HBASE-21320) | *Major* | **[canary] Cleanup of usage and add commentary**
+
+Cleans up usage and docs around Canary. Does not change command-line args (though we should -- smile).
+
+
+---
+
+* [HBASE-21278](https://issues.apache.org/jira/browse/HBASE-21278) | *Critical* | **Do not rollback successful sub procedures when rolling back a procedure**
+
+For the sub procedures which are successfully finished, do not do rollback. This is a change in rollback behavior.
+
+State changes which are done by sub procedures should be handled by parent procedures when rolling back. For example, when rolling back a MergeTableProcedure, we will schedule new procedures to bring the offline regions online instead of rolling back the original procedures which off-lined the regions (in fact these procedures can not be rolled back...).
+
+
+---
+
+* [HBASE-21158](https://issues.apache.org/jira/browse/HBASE-21158) | *Critical* | **Empty qualifier cell should not be returned if it does not match QualifierFilter**
+
+<!-- markdown -->
+
+Scans that make use of `QualifierFilter` previously would erroneously return both columns with an empty qualifier along with those that matched. After this change that behavior has changed to only return those columns that match.
+
+
+---
+
+* [HBASE-21098](https://issues.apache.org/jira/browse/HBASE-21098) | *Major* | **Improve Snapshot Performance with Temporary Snapshot Directory when rootDir on S3**
+
+It is recommended to place the working directory on-cluster on HDFS as doing so has shown a strong performance increase due to data locality. It is important to note that the working directory should not overlap with any existing directories as the working directory will be cleaned out during the snapshot process. Beyond that, any well-named directory on HDFS should be sufficient.
+
+
+---
+
+* [HBASE-21185](https://issues.apache.org/jira/browse/HBASE-21185) | *Minor* | **WALPrettyPrinter: Additional useful info to be printed by wal printer tool, for debugability purposes**
+
+This adds two extra features to WALPrettyPrinter tool:
+
+1) Output for each cell combined size of cell descriptors, plus the cell value itself, in a given WAL edit. This is printed on the results as "cell total size sum:" info by default;
+
+2) An optional -g/--goto argument, that allows to seek straight to that specific WAL file position, then sequentially reading the WAL from that point towards its end;
+
+
+---
+
+* [HBASE-21287](https://issues.apache.org/jira/browse/HBASE-21287) | *Major* | **JVMClusterUtil Master initialization wait time not configurable**
+
+Local HBase cluster (as used by unit tests) wait times on startup and initialization can be configured via \`hbase.master.start.timeout.localHBaseCluster\` and \`hbase.master.init.timeout.localHBaseCluster\`
+
+
+---
+
+* [HBASE-21280](https://issues.apache.org/jira/browse/HBASE-21280) | *Trivial* | **Add anchors for each heading in UI**
+
+Adds anchors #tables, #tasks, etc.
+
+
+---
+
+* [HBASE-21232](https://issues.apache.org/jira/browse/HBASE-21232) | *Major* | **Show table state in Tables view on Master home page**
+
+Add table state column to the tables panel
+
+
+---
+
+* [HBASE-21223](https://issues.apache.org/jira/browse/HBASE-21223) | *Critical* | **[amv2] Remove abort\_procedure from shell**
+
+Removed the abort\_procedure command from shell -- dangerous -- and deprecated abortProcedure in Admin API.
+
+
+---
+
+* [HBASE-20636](https://issues.apache.org/jira/browse/HBASE-20636) | *Major* | **Introduce two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED**
+
+Add two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED
+1. ROWPREFIX\_FIXED\_LENGTH: specify the length of the prefix
+2. ROWPREFIX\_DELIMITED: specify the delimiter of the prefix
+Need to specify parameters for these two types of bloomfilter, otherwise the table will fail to create
+Example:
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_FIXED\_LENGTH', CONFIGURATION =\> {'RowPrefixBloomFilter.prefix\_length' =\> '10'}}
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_DELIMITED', CONFIGURATION =\> {'RowPrefixDelimitedBloomFilter.delimiter' =\> '#'}}
+
+
+---
+
+* [HBASE-21156](https://issues.apache.org/jira/browse/HBASE-21156) | *Critical* | **[hbck2] Queue an assign of hbase:meta and bulk assign/unassign**
+
+Adds 'raw' assigns/unassigns to the Hbck Service. Takes a list of encoded region names and bulk assigns/unassigns. Skirts Master 'state' check and does not invoke Coprocessors. For repair only.
+
+Here is what HBCK2 usage looks like now:
+
+{code}
+$ java -cp hbase-hbck2-1.0.0-SNAPSHOT.jar org.apache.hbase.HBCK2
+usage: HBCK2 \<OPTIONS\> COMMAND [\<ARGS\>]
+
+Options:
+ -d,--debug run with debug output
+ -h,--help output this help message
+ --hbase.zookeeper.peerport peerport of target hbase ensemble
+ --hbase.zookeeper.quorum ensemble of target hbase
+ --zookeeper.znode.parent parent znode of target hbase
+
+Commands:
+ setTableState \<TABLENAME\> \<STATE\>
+ Possible table states: ENABLED, DISABLED, DISABLING, ENABLING
+ To read current table state, in the hbase shell run:
+ hbase\> get 'hbase:meta', '\<TABLENAME\>', 'table:state'
+ A value of \\x08\\x00 == ENABLED, \\x08\\x01 == DISABLED, etc.
+ An example making table name 'user' ENABLED:
+ $ HBCK2 setTableState users ENABLED
+ Returns whatever the previous table state was.
+
+ assign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' assign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ e.g. 1588230740 is hard-coded encoding for hbase:meta region and
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 assign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created AssignProcedure or -1 if none.
+
+ unassign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' unassign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 unassign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created UnassignProcedure or -1 if none.
+{code}
+
+
+---
+
+* [HBASE-21021](https://issues.apache.org/jira/browse/HBASE-21021) | *Major* | **Result returned by Append operation should be ordered**
+
+This change ensures Append operations are assembled into the expected order.
+
+
+---
+
+* [HBASE-21171](https://issues.apache.org/jira/browse/HBASE-21171) | *Major* | **[amv2] Tool to parse a directory of MasterProcWALs standalone**
+
+Make it so can run the WAL parse and load system in isolation. Here is an example:
+
+{code}$ HBASE\_OPTS=" -XX:+UnlockDiagnosticVMOptions -XX:+UnlockCommercialFeatures -XX:+FlightRecorder -XX:+DebugNonSafepoints" ./bin/hbase org.apache.hadoop.hbase.procedure2.store.wal.WALProcedureStore ~/big\_set\_of\_masterprocwals/
+{code}
+
+
+---
+
+* [HBASE-21107](https://issues.apache.org/jira/browse/HBASE-21107) | *Minor* | **add a metrics for netty direct memory**
+
+Add a new nettyDirectMemoryUsage under server's ipc metrics to show direct memory usage for netty rpc server.
+
+
+---
+
+* [HBASE-21153](https://issues.apache.org/jira/browse/HBASE-21153) | *Major* | **Shaded client jars should always build in relevant phase to avoid confusion**
+
+Client facing artifacts are now built whenever Maven is run through the "package" goal. Previously, the client facing artifacts would create placeholder jars that skipped repackaging HBase and third-party dependencies unless the "release" profile was active.
+
+Build times may be noticeably longer depending on your build hardware. For example, the Jenkins worker nodes maintained by ASF Infra take ~14% longer to do a full packaging build. An example portability-focused personal laptop took ~25% longer.
+
+
+---
+
+* [HBASE-20942](https://issues.apache.org/jira/browse/HBASE-20942) | *Major* | **Improve RpcServer TRACE logging**
+
+Allows configuration of the length of RPC messages printed to the log at TRACE level via "hbase.ipc.trace.param.size" in RpcServer.
+
+
+---
+
+* [HBASE-20649](https://issues.apache.org/jira/browse/HBASE-20649) | *Minor* | **Validate HFiles do not have PREFIX\_TREE DataBlockEncoding**
+
+<!-- markdown -->
+Users who have previously made use of prefix tree encoding can now check that their existing HFiles no longer contain data that uses it with an additional preupgrade check command.
+
+```
+hbase pre-upgrade validate-hfile
+```
+
+Please see the "HFile Content validation" section of the ref guide's coverage of the pre-upgrade validator tool for usage details.
+
+
+---
+
+* [HBASE-20941](https://issues.apache.org/jira/browse/HBASE-20941) | *Major* | **Create and implement HbckService in master**
+
+Adds an HBCK Service and a first method to force-change-in-table-state for use by an HBCK client effecting 'repair' to a malfunctioning HBase.
+
+
+---
+
+* [HBASE-21071](https://issues.apache.org/jira/browse/HBASE-21071) | *Major* | **HBaseTestingUtility::startMiniCluster() to use builder pattern**
+
+Cleanup all the cluster start override combos in HBaseTestingUtility by adding a StartMiniClusterOption and Builder.
+
+
+---
+
+* [HBASE-21072](https://issues.apache.org/jira/browse/HBASE-21072) | *Major* | **Block out HBCK1 in hbase2**
+
+Fence out hbase-1.x hbck1 instances. Stop them making state changes on an hbase-2.x cluster; they could do damage. We do this by writing the hbck1 lock file into place on hbase-2.x Master start-up.
+
+To disable this new behavior, set hbase.write.hbck1.lock.file to false
+
+
+---
+
+* [HBASE-20881](https://issues.apache.org/jira/browse/HBASE-20881) | *Major* | **Introduce a region transition procedure to handle all the state transition for a region**
+
+Introduced a new TransitRegionStateProcedure to replace the old AssignProcedure/UnassignProcedure/MoveRegionProcedure. In the old code, MRP will not be attached to RegionStateNode, so it can not be interrupted by ServerCrashProcedure, which introduces lots of tricky code to deal with races, and also causes lots of other difficulties on how to prevent scheduling redundant or even conflict procedures for a region.
+
+And now TRSP is the only one procedure which can bring region online or offline. When you want to schedule one, you need to check whether there is already one attached to the RegionStateNode, under the lock of the RegionStateNode. If not just go ahead, and if there is one, then you should do something, for example, give up and fail directly, or tell the TRSP to give up(This is what SCP does). Since the check and attach are both under the lock of RSN, it will greatly reduce the possible r [...]
+
+
+---
+
+* [HBASE-21012](https://issues.apache.org/jira/browse/HBASE-21012) | *Critical* | **Revert the change of serializing TimeRangeTracker**
+
+HFiles generated by 2.0.0, 2.0.1, 2.1.0 are not forward compatible to 1.4.6-, 1.3.2.1-, 1.2.6.1-, and other inactive releases. Why HFile lose compatability is hbase in new versions (2.0.0, 2.0.1, 2.1.0) use protobuf to serialize/deserialize TimeRangeTracker (TRT) while old versions use DataInput/DataOutput. To solve this, We have to put HBASE-21012 to 2.x and put HBASE-21013 in 1.x. For more information, please check HBASE-21008.
+
+
+---
+
+* [HBASE-20965](https://issues.apache.org/jira/browse/HBASE-20965) | *Major* | **Separate region server report requests to new handlers**
+
+After HBASE-20965, we can use MasterFifoRpcScheduler in master to separate RegionServerReport requests to indenpedent handler. To use this feature, please set "hbase.master.rpc.scheduler.factory.class" to
+ "org.apache.hadoop.hbase.ipc.MasterFifoRpcScheduler". Use "hbase.master.server.report.handler.count" to set RegionServerReport handlers count, the default value is half of "hbase.regionserver.handler.count" value, but at least 1, and the other handlers count in master is "hbase.regionserver.handler.count" value minus RegionServerReport handlers count, but at least 1 too.
+
+
+---
+
+* [HBASE-20813](https://issues.apache.org/jira/browse/HBASE-20813) | *Minor* | **Remove RPC quotas when the associated table/Namespace is dropped off**
+
+In previous releases, when a Space Quota was configured on a table or namespace and that table or namespace was deleted, the Space Quota was also deleted. This change improves the implementation so that the same is also done for RPC Quotas.
+
+
+---
+
+* [HBASE-20986](https://issues.apache.org/jira/browse/HBASE-20986) | *Major* | **Separate the config of block size when we do log splitting and write Hlog**
+
+After HBASE-20986, we can set different value to block size of WAL and recovered edits. Both of their default value is 2 \* default HDFS blocksize. And hbase.regionserver.recoverededits.blocksize is for block size of recovered edits while hbase.regionserver.hlog.blocksize is for block size of WAL.
+
+
+---
+
+* [HBASE-20856](https://issues.apache.org/jira/browse/HBASE-20856) | *Minor* | **PITA having to set WAL provider in two places**
+
+With this change if a WAL's meta provider (hbase.wal.meta\_provider) is not explicitly set, it now defaults to whatever hbase.wal.provider is set to. Previous, the two settings operated independently, each with its own default.
+
+This change is operationally incompatible with previous HBase versions because the default WAL meta provider no longer defaults to AsyncFSWALProvider but to hbase.wal.provider.
+
+The thought is that this is more in line with an operator's expectation, that a change in hbase.wal.provider is sufficient to change how WALs are written, especially given hbase.wal.meta\_provider is an obscure configuration and that the very idea that meta regions would have their own wal provider would likely come as a surprise.
+
+
+---
+
+* [HBASE-20538](https://issues.apache.org/jira/browse/HBASE-20538) | *Critical* | **Upgrade our hadoop versions to 2.7.7 and 3.0.3**
+
+Update hadoop-two.version to 2.7.7 and hadoop-three.version to 3.0.3 due to a JDK issue which is solved by HADOOP-15473.
+
+
+---
+
+* [HBASE-20846](https://issues.apache.org/jira/browse/HBASE-20846) | *Major* | **Restore procedure locks when master restarts**
+
+1. Make hasLock method final, and add a locked field in Procedure to record whether we have the lock. We will set it to true in doAcquireLock and to false in doReleaseLock. The sub procedures do not need to manage it any more.
+
+2. Also added a locked field in the proto message. When storing, the field will be set according to the return value of hasLock. And when loading, there is a new field in Procedure called lockedWhenLoading. We will set it to true if the locked field in proto message is true.
+
+3. The reason why we can not set the locked field directly to true by calling doAcquireLock is that, during initialization, most procedures need to wait until master is initialized. So the solution here is that, we introduced a new method called waitInitialized in Procedure, and move the wait master initialized related code from acquireLock to this method. And we added a restoreLock method to Procedure, if lockedWhenLoading is true, we will call the acquireLock to get the lock, but do no [...]
+
+
+---
+
+* [HBASE-20672](https://issues.apache.org/jira/browse/HBASE-20672) | *Minor* | **New metrics ReadRequestRate and WriteRequestRate**
+
+Exposing 2 new metrics in HBase to provide ReadRequestRate and WriteRequestRate at region server level. These metrics give the rate of request handled by the region server and are reset after every monitoring interval.
+
+
+---
+
+* [HBASE-6028](https://issues.apache.org/jira/browse/HBASE-6028) | *Minor* | **Implement a cancel for in-progress compactions**
+
+Added a new command to the shell to switch on/off compactions called "compaction\_switch". Disabling compactions will interrupt any currently ongoing compactions. This setting will be lost on restart of the server. Added the configuration hbase.regionserver.compaction.enabled so user can enable/disable compactions via hbase-site.xml.
+
+
+---
+
+* [HBASE-20884](https://issues.apache.org/jira/browse/HBASE-20884) | *Major* | **Replace usage of our Base64 implementation with java.util.Base64**
+
+Class org.apache.hadoop.hbase.util.Base64 has been removed in it's entirety from HBase 2+. In HBase 1, unused methods have been removed from the class and the audience was changed from Public to Private. This class was originally intended as an internal utility class that could be used externally but thinking since changed; these classes should not have been advertised as public to end-users.
+
+This represents an incompatible change for users who relied on this implementation. An alternative implementation for affected clients is available at java.util.Base64 when using Java 8 or newer; be aware, it may encode/decode differently. For clients seeking to restore this specific implementation, it is available in the public domain for download at http://iharder.sourceforge.net/current/java/base64/
+
+
+---
+
+* [HBASE-20357](https://issues.apache.org/jira/browse/HBASE-20357) | *Major* | **AccessControlClient API Enhancement**
+
+This enhances the AccessControlClient APIs to retrieve the permissions based on namespace, table name, family and qualifier for specific user. AccessControlClient can also validate a user whether allowed to perform specified operations on a particular table.
+Following APIs have been added,
+1) getUserPermissions(Connection connection, String tableRegex, byte[] columnFamily, byte[] columnQualifier, String userName)
+ Scope of retrieving permission will be same as existing.
+2) hasPermission(onnection connection, String tableName, byte[] columnFamily, byte[] columnQualifier, String userName, Permission.Action... actions)
+ Scope of validating user privilege,
+ User can perform self check without any special privilege but ADMIN privilege will be required to perform check for other users.
+ For example, suppose there are two users "userA" & "userB" then there can be below scenarios,
+ a. When userA want to check whether userA have privilege to perform mentioned actions
+ userA don't need ADMIN privilege, as it's a self query.
+ b. When userA want to check whether userB have privilege to perform mentioned actions,
+ userA must have ADMIN or superuser privilege, as it's trying to query for other user.
+
+
+
+Fixed awkward dependency issue that prevented site building.
+
+#### note specific to HBase 2.1.4
+HBase 2.1.4 shipped with an early version of this fix that incorrectly altered the libraries included in our binary assembly for using Apache Hadoop 2.7 (the current build default Hadoop version for 2.1.z). For folks running out of the box against a Hadoop 2.7 cluster (or folks who skip the installation step of [replacing the bundled Hadoop libraries](http://hbase.apache.org/book.html#hadoop)) this will result in a failure at Region Server startup due to a missing class definition. e.g.:
+```
+2019-03-27 09:02:05,779 ERROR [main] regionserver.HRegionServer: Failed construction RegionServer
+java.lang.NoClassDefFoundError: org/apache/htrace/SamplerBuilder
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:644)
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:628)
+ at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
+ at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)
+ at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:93)
+ at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2701)
+ at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2683)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:372)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:171)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:356)
+ at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getRootDir(CommonFSUtils.java:362)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.isValidWALRootDir(CommonFSUtils.java:411)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getWALRootDir(CommonFSUtils.java:387)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.initializeFileSystem(HRegionServer.java:704)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.<init>(HRegionServer.java:613)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
+ at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
+ at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.constructRegionServer(HRegionServer.java:3029)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.start(HRegionServerCommandLine.java:63)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.run(HRegionServerCommandLine.java:87)
+ at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
+ at org.apache.hadoop.hbase.util.ServerCommandLine.doMain(ServerCommandLine.java:149)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.main(HRegionServer.java:3047)
+Caused by: java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
+ at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
+ at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
+ ... 26 more
+
+```
+
+Workaround via any _one_ of the following:
+* If you are running against a Hadoop cluster that is 2.8+, ensure you replace the Hadoop libaries in the default binary assembly with those for your version.
+* If you are running against a Hadoop cluster that is 2.8+, build the binary assembly from the source release while specifying your Hadoop version.
+* If you are running against a Hadoop cluster that is a supported 2.7 release, ensure the `hadoop` executable is in the `PATH` seen at Region Server startup and that you are not using the `HBASE_DISABLE_HADOOP_CLASSPATH_LOOKUP` bypass.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers via the HBASE_CLASSPATH environment variable.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers by copying it into the directory `${HBASE_HOME}/lib/client-facing-thirdparty/`.
+
+
+---
+
+* [HBASE-22065](https://issues.apache.org/jira/browse/HBASE-22065) | *Major* | **Add listTableDescriptors(List\<TableName\>) method in AsyncAdmin**
+
+Add a listTableDescriptors(List\<TableName\>) method in the AsyncAdmin interface, to align with the Admin interface.
+
+
+---
+
+* [HBASE-22040](https://issues.apache.org/jira/browse/HBASE-22040) | *Major* | **Add mergeRegionsAsync with a List of region names method in AsyncAdmin**
+
+Add a mergeRegionsAsync(byte[][], boolean) method in the AsyncAdmin interface.
+
+Instead of using assert, now we will throw IllegalArgumentException when you want to merge less than 2 regions at client side. And also, at master side, instead of using assert, now we will throw DoNotRetryIOException if you want merge more than 2 regions, since we only support merging two regions at once for now.
+
+
+---
+
+* [HBASE-22039](https://issues.apache.org/jira/browse/HBASE-22039) | *Major* | **Should add the synchronous parameter for the XXXSwitch method in AsyncAdmin**
+
+Add drainXXX parameter for balancerSwitch/splitSwitch/mergeSwitch methods in the AsyncAdmin interface, which has the same meaning with the synchronous parameter for these methods in the Admin interface.
+
+
+---
+
+* [HBASE-21810](https://issues.apache.org/jira/browse/HBASE-21810) | *Major* | **bulkload support set hfile compression on client**
+
+bulkload (HFileOutputFormat2) support config the compression on client ,you can set the job configuration "hbase.mapreduce.hfileoutputformat.compression" override the auto-detection of the target table's compression
+
+
+---
+
+* [HBASE-22000](https://issues.apache.org/jira/browse/HBASE-22000) | *Major* | **Deprecated isTableAvailable with splitKeys**
+
+Deprecated AsyncTable.isTableAvailable(TableName, byte[][]).
+
+
+---
+
+* [HBASE-21871](https://issues.apache.org/jira/browse/HBASE-21871) | *Major* | **Support to specify a peer table name in VerifyReplication tool**
+
+After HBASE-21871, we can specify a peer table name with --peerTableName in VerifyReplication tool like the following:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable 5 TestTable
+
+In addition, we can compare any 2 tables in any remote clusters with specifying both peerId and --peerTableName.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable zk1,zk2,zk3:2181/hbase TestTable
+
+
+---
+
+* [HBASE-15728](https://issues.apache.org/jira/browse/HBASE-15728) | *Major* | **Add remaining per-table region / store / flush / compaction related metrics**
+
+Adds below flush, split, and compaction metrics
+
+ + // split related metrics
+ + private MutableFastCounter splitRequest;
+ + private MutableFastCounter splitSuccess;
+ + private MetricHistogram splitTimeHisto;
+ +
+ + // flush related metrics
+ + private MetricHistogram flushTimeHisto;
+ + private MetricHistogram flushMemstoreSizeHisto;
+ + private MetricHistogram flushOutputSizeHisto;
+ + private MutableFastCounter flushedMemstoreBytes;
+ + private MutableFastCounter flushedOutputBytes;
+ +
+ + // compaction related metrics
+ + private MetricHistogram compactionTimeHisto;
+ + private MetricHistogram compactionInputFileCountHisto;
+ + private MetricHistogram compactionInputSizeHisto;
+ + private MetricHistogram compactionOutputFileCountHisto;
+ + private MetricHistogram compactionOutputSizeHisto;
+ + private MutableFastCounter compactedInputBytes;
+ + private MutableFastCounter compactedOutputBytes;
+ +
+ + private MetricHistogram majorCompactionTimeHisto;
+ + private MetricHistogram majorCompactionInputFileCountHisto;
+ + private MetricHistogram majorCompactionInputSizeHisto;
+ + private MetricHistogram majorCompactionOutputFileCountHisto;
+ + private MetricHistogram majorCompactionOutputSizeHisto;
+ + private MutableFastCounter majorCompactedInputBytes;
+ + private MutableFastCounter majorCompactedOutputBytes;
+
+
+---
+
+* [HBASE-20886](https://issues.apache.org/jira/browse/HBASE-20886) | *Critical* | **[Auth] Support keytab login in hbase client**
+
+From 2.2.0, hbase supports client login via keytab. To use this feature, client should specify \`hbase.client.keytab.file\` and \`hbase.client.keytab.principal\` in hbase-site.xml, then the connection will contain the needed credentials which be renewed periodically to communicate with kerberized hbase cluster.
+
+
+---
+
+* [HBASE-21410](https://issues.apache.org/jira/browse/HBASE-21410) | *Major* | **A helper page that help find all problematic regions and procedures**
+
+After HBASE-21410, we add a helper page to Master UI. This helper page is mainly to help HBase operator quickly found all regions and pids that are get stuck.
+There are 2 entries to get in this page.
+One is showing in the Regions in Transition section, it made "num region(s) in transition" a link that you can click and check all regions in transition and their related procedure IDs.
+The other one is showing in the table details section, it made the number of CLOSING or OPENING regions a link, which you can click and check regions and related procedure IDs of CLOSING or OPENING regions of a certain table.
+In this helper page, not only you can see all regions and related procedures, there are 2 buttons at the top which will show these regions or procedure IDs in text format. This is mainly aim to help operator to easily copy and paste all problematic procedure IDs and encoded region names to HBCK2's command line, by which we HBase operator can bypass these procedures or assign these regions.
+
+
+---
+
+* [HBASE-21588](https://issues.apache.org/jira/browse/HBASE-21588) | *Major* | **Procedure v2 wal splitting implementation**
+
+After HBASE-21588, we introduce a new way to do WAL splitting coordination by procedure framework. This can simplify the process of WAL splitting and no need to connect zookeeper any more.
+During ServerCrashProcedure, it will create a SplitWALProcedure for each WAL that need to split. Then each SplitWALProcedure will spawn a SplitWALRemoteProcedure to send the request to regionserver.
+At the RegionServer side, whole process is handled by SplitWALCallable. It split the WAL and return the result to master.
+According to my test, this patch has a better performance as the number of WALs that need to split increase. And it can relieve the pressure on zookeeper.
+
+
+---
+
+* [HBASE-20734](https://issues.apache.org/jira/browse/HBASE-20734) | *Major* | **Colocate recovered edits directory with hbase.wal.dir**
+
+Previously the recovered.edits directory was under the root directory. This JIRA moves the recovered.edits directory to be under the hbase.wal.dir if set. It also adds a check for any recovered.edits found under the root directory for backwards compatibility. This gives improvements when a faster media(like SSD) or more local FileSystem is used for the hbase.wal.dir than the root dir.
+
+
+---
+
+* [HBASE-20401](https://issues.apache.org/jira/browse/HBASE-20401) | *Minor* | **Make \`MAX\_WAIT\` and \`waitIfNotFinished\` in CleanerContext configurable**
+
+When oldwals (and hfile) cleaner cleans stale wals (and hfiles), it will periodically check and wait the clean results from filesystem, the total wait time will be no more than a max time.
+
+The periodically wait and check configurations are hbase.oldwals.cleaner.thread.check.interval.msec (default is 500 ms) and hbase.regionserver.hfilecleaner.thread.check.interval.msec (default is 1000 ms).
+
+Meanwhile, The max time configurations are hbase.oldwals.cleaner.thread.timeout.msec and hbase.regionserver.hfilecleaner.thread.timeout.msec, they are set to 60 seconds by default.
+
+All support dynamic configuration.
+
+e.g. in the oldwals cleaning scenario, one may consider tuning hbase.oldwals.cleaner.thread.timeout.msec and hbase.oldwals.cleaner.thread.check.interval.msec
+
+1. While deleting a oldwal never complete (strange but possible), then delete file task needs to wait for a max of 60 seconds. Here, 60 seconds might be too long, or the opposite way is to increase more than 60 seconds in the use cases of slow file delete.
+2. The check and wait of a file delete is set to default in the period of 500 milliseconds, one might want to tune this checking period to a short interval to check more frequently or to a longer interval to avoid checking too often to manage their delete file task checking period (the longer interval may be use to avoid checking too fast while using a high latency storage).
+
+
+---
+
+* [HBASE-21481](https://issues.apache.org/jira/browse/HBASE-21481) | *Major* | **[acl] Superuser's permissions should not be granted or revoked by any non-su global admin**
+
+HBASE-21481 improves the quality of access control, by strengthening the protection of super users's privileges.
+
+
+---
+
+* [HBASE-21082](https://issues.apache.org/jira/browse/HBASE-21082) | *Critical* | **Reimplement assign/unassign related procedure metrics**
+
+Now we have four types of RIT procedure metrics, assign, unassign, move, reopen. The meaning of assign/unassign is changed, as we will not increase the unassign metric and then the assign metric when moving a region.
+Also introduced two new procedure metrics, open and close, which are used to track the open/close region calls to region server. We may send open/close multiple times to finish a RIT since we may retry multiple times.
+
+
+---
+
+* [HBASE-20724](https://issues.apache.org/jira/browse/HBASE-20724) | *Critical* | **Sometimes some compacted storefiles are still opened after region failover**
+
+Problem: This is an old problem since HBASE-2231. The compaction event marker was only writed to WAL. But after flush, the WAL may be archived, which means an useful compaction event marker be deleted, too. So the compacted store files cannot be archived when region open and replay WAL.
+
+Solution: After this jira, the compaction event tracker will be writed to HFile. When region open and load store files, read the compaction evnet tracker from HFile and archive the compacted store files which still exist.
+
+
+---
+
+* [HBASE-21820](https://issues.apache.org/jira/browse/HBASE-21820) | *Major* | **Implement CLUSTER quota scope**
+
+HBase contains two quota scopes: MACHINE and CLUSTER. Before this patch, set quota operations did not expose scope option to client api and use MACHINE as default, CLUSTER scope can not be set and used.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+
+This issue implements CLUSTER scope in a simple way: For user, namespace, user over namespace quota, use [ClusterLimit / RSNum] as machine limit. For table and user over table quota, use [ClusterLimit / TotalTableRegionNum \* MachineTableRegionNum] as machine limit.
+After this patch, user can set CLUSTER scope quota, but MACHINE is still default if user ignore scope.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> MACHINE
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> CLUSTER
+
+
+---
+
+* [HBASE-21057](https://issues.apache.org/jira/browse/HBASE-21057) | *Minor* | **upgrade to latest spotbugs**
+
+Change spotbugs version to 3.1.11.
+
+
+---
+
+* [HBASE-21922](https://issues.apache.org/jira/browse/HBASE-21922) | *Major* | **BloomContext#sanityCheck may failed when use ROWPREFIX\_DELIMITED bloom filter**
+
+Remove bloom filter type ROWPREFIX\_DELIMITED. May add it back when find a better solution.
+
+
+---
+
+* [HBASE-21783](https://issues.apache.org/jira/browse/HBASE-21783) | *Major* | **Support exceed user/table/ns throttle quota if region server has available quota**
+
+Support enable or disable exceed throttle quota. Exceed throttle quota means, user can over consume user/namespace/table quota if region server has additional available quota because other users don't consume at the same time.
+Use the following shell commands to enable/disable exceed throttle quota: enable\_exceed\_throttle\_quota
+disable\_exceed\_throttle\_quota
+There are two limits when enable exceed throttle quota:
+1. Must set at least one read and one write region server throttle quota;
+2. All region server throttle quotas must be in seconds time unit. Because once previous requests exceed their quota and consume region server quota, quota in other time units may be refilled in a long time, this may affect later requests.
+
+
+---
+
+* [HBASE-20587](https://issues.apache.org/jira/browse/HBASE-20587) | *Major* | **Replace Jackson with shaded thirdparty gson**
+
+Remove jackson dependencies from most hbase modules except hbase-rest, use shaded gson instead. The output json will be a bit different since jackson can use getter/setter, but gson will always use the fields.
+
+
+---
+
+* [HBASE-21928](https://issues.apache.org/jira/browse/HBASE-21928) | *Major* | **Deprecated HConstants.META\_QOS**
+
+Mark HConstants.META\_QOS as deprecated. It is for internal use only, which is the highest priority. You should not try to set a priority greater than or equal to this value, although it is no harm but also useless.
+
+
+---
+
+* [HBASE-17942](https://issues.apache.org/jira/browse/HBASE-17942) | *Major* | **Disable region splits and merges per table**
+
+This patch adds the ability to disable split and/or merge for a table (By default, split and merge are enabled for a table).
+
+
+---
+
+* [HBASE-21636](https://issues.apache.org/jira/browse/HBASE-21636) | *Major* | **Enhance the shell scan command to support missing scanner specifications like ReadType, IsolationLevel etc.**
+
+Allows shell to set Scan options previously not exposed. See additions as part of the scan help by typing following hbase shell:
+
+hbase\> help 'scan'
+
+
+---
+
+* [HBASE-21201](https://issues.apache.org/jira/browse/HBASE-21201) | *Major* | **Support to run VerifyReplication MR tool without peerid**
+
+We can specify peerQuorumAddress instead of peerId in VerifyReplication tool. So it no longer requires peerId to be setup when using this tool.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication zk1,zk2,zk3:2181/hbase testTable
+
+
+---
+
+* [HBASE-21838](https://issues.apache.org/jira/browse/HBASE-21838) | *Major* | **Create a special ReplicationEndpoint just for verifying the WAL entries are fine**
+
+Introduce a VerifyWALEntriesReplicationEndpoint which replicates nothing but only verifies if all the cells are valid.
+It can be used to capture bugs for writing WAL, as most times we will not read the WALs again after writing it if there are no region server crashes.
+
+
+---
+
+* [HBASE-21727](https://issues.apache.org/jira/browse/HBASE-21727) | *Minor* | **Simplify documentation around client timeout**
+
+Deprecated HBaseConfiguration#getInt(Configuration, String, String, int) method and removed it from 3.0.0 version.
+
+
+---
+
+* [HBASE-21764](https://issues.apache.org/jira/browse/HBASE-21764) | *Major* | **Size of in-memory compaction thread pool should be configurable**
+
+Introduced an new config key in this issue: hbase.regionserver.inmemory.compaction.pool.size. the default value would be 10. you can configure this to set the pool size of in-memory compaction pool. Note that all memstores in one region server will share the same pool, so if you have many regions in one region server, you need to set this larger to compact faster for better read performance.
+
+
+---
+
+* [HBASE-21684](https://issues.apache.org/jira/browse/HBASE-21684) | *Major* | **Throw DNRIOE when connection or rpc client is closed**
+
+Make StoppedRpcClientException extend DoNotRetryIOException.
+
+
+---
+
+* [HBASE-21739](https://issues.apache.org/jira/browse/HBASE-21739) | *Major* | **Move grant/revoke from regionserver to master**
+
+To implement user permission control in Precedure V2, move grant and revoke method from AccessController to master firstly.
+Mark AccessController#grant and AccessController#revoke as deprecated and please use Admin#grant and Admin#revoke instead.
+
+
+---
+
+* [HBASE-21791](https://issues.apache.org/jira/browse/HBASE-21791) | *Blocker* | **Upgrade thrift dependency to 0.12.0**
+
+IMPORTANT: Due to security issues, all users who use hbase thrift should avoid using releases which do not have this fix.
+
+The effect releases are:
+2.1.x: 2.1.2 and below
+2.0.x: 2.0.4 and below
+1.x: 1.4.x and below
+
+If you are using the effect releases above, please consider upgrading to a newer release ASAP.
+
+
+---
+
+* [HBASE-21792](https://issues.apache.org/jira/browse/HBASE-21792) | *Major* | **Mark HTableMultiplexer as deprecated and remove it in 3.0.0**
+
+HTableMultiplexer exposes the implementation class, and it is incomplete, so we mark it as deprecated and remove it in 3.0.0 release.
+
+There is no direct replacement for HTableMultiplexer, please use BufferedMutator if you want to batch mutations to a table.
+
+
+---
+
+* [HBASE-21782](https://issues.apache.org/jira/browse/HBASE-21782) | *Major* | **LoadIncrementalHFiles should not be IA.Public**
+
+Introduce a BulkLoadHFiles interface which is marked as IA.Public, for doing bulk load programmatically.
+Introduce a BulkLoadHFilesTool which extends BulkLoadHFiles, and is marked as IA.LimitedPrivate(TOOLS), for using from command line.
+The old LoadIncrementalHFiles is deprecated and will be removed in 3.0.0.
+
+
+---
+
+* [HBASE-21762](https://issues.apache.org/jira/browse/HBASE-21762) | *Major* | **Move some methods in ClusterConnection to Connection**
+
+Move the two getHbck method from ClusterConnection to Connection, and mark the methods as IA.LimitedPrivate(HBCK), as ClusterConnection is IA.Private and should not be depended by HBCK2.
+
+Add a clearRegionLocationCache method in Connection to clear the region location cache for all the tables. As in RegionLocator, most of the methods have a 'reload' parameter, which implicitly tells user that we have a region location cache, so adding a method to clear the cache is fine.
+
+
+---
+
+* [HBASE-21713](https://issues.apache.org/jira/browse/HBASE-21713) | *Major* | **Support set region server throttle quota**
+
+Support set region server rpc throttle quota which represents the read/write ability of region servers and throttles when region server's total requests exceeding the limit.
+
+Use the following shell command to set RS quota:
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', THROTTLE\_TYPE =\> WRITE, LIMIT =\> '20000req/sec'
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', LIMIT =\> NONE
+"all" represents the throttle quota of all region servers and setting specified region server quota isn't supported currently.
+
+
+---
+
+* [HBASE-21689](https://issues.apache.org/jira/browse/HBASE-21689) | *Minor* | **Make table/namespace specific current quota info available in shell(describe\_namespace & describe)**
+
+In shell commands "describe\_namespace" and "describe", which are used to see the descriptors of the namespaces and tables respectively, quotas set on that particular namespace/table will also be printed along.
+
+
+---
+
+* [HBASE-17370](https://issues.apache.org/jira/browse/HBASE-17370) | *Major* | **Fix or provide shell scripts to drain and decommission region server**
+
+Adds shell support for the following:
+- List decommissioned/draining region servers
+- Decommission a list of region servers, optionally offload corresponding regions
+- Recommission a region server, optionally load a list of passed regions
+
+
+---
+
+* [HBASE-21734](https://issues.apache.org/jira/browse/HBASE-21734) | *Major* | **Some optimization in FilterListWithOR**
+
+After HBASE-21620, the filterListWithOR has been a bit slow because we need to merge each sub-filter's RC , while before HBASE-21620, we will skip many RC merging, but the logic was wrong. So here we choose another way to optimaze the performance: removing the KeyValueUtil#toNewKeyCell.
+Anoop Sam John suggested that the KeyValueUtil#toNewKeyCell can save some GC before because if we copy key part of cell into a single byte[], then the block the cell refering won't be refered by the filter list any more, the upper layer can GC the data block quickly. while after HBASE-21620, we will update the prevCellList for every encountered cell now, so the lifecycle of cell in prevCellList for FilterList will be quite shorter. so just use the cell ref for saving cpu.
+BTW, we removed all the arrays streams usage in filter list, because it's also quite time-consuming in our test.
+
+
+---
+
+* [HBASE-21738](https://issues.apache.org/jira/browse/HBASE-21738) | *Critical* | **Remove all the CSLM#size operation in our memstore because it's an quite time consuming.**
+
+We found the memstore snapshotting would cost much time because of calling the time-consuming ConcurrentSkipListMap#Size, it would make the p999 latency spike happen. So in this issue, we remove all ConcurrentSkipListMap#size in memstore by counting the cellsCount in MemstoreSizeing. As the issue described, the p999 latency spike was mitigated.
+
+
+---
+
+* [HBASE-21034](https://issues.apache.org/jira/browse/HBASE-21034) | *Major* | **Add new throttle type: read/write capacity unit**
+
+Provides a new throttle type: capacity unit. One read/write/request capacity unit represents that read/write/read+write up to 1K data. If data size is more than 1K, then consume additional capacity units.
+
+Use shell command to set capacity unit(CU):
+set\_quota TYPE =\> THROTTLE, THROTTLE\_TYPE =\> WRITE, USER =\> 'u1', LIMIT =\> '10CU/sec'
+
+Use the "hbase.quota.read.capacity.unit" property to set the data size of one read capacity unit in bytes, the default value is 1K. Use the "hbase.quota.write.capacity.unit" property to set the data size of one write capacity unit in bytes, the default value is 1K.
+
+
+---
+
+* [HBASE-21595](https://issues.apache.org/jira/browse/HBASE-21595) | *Minor* | **Print thread's information and stack traces when RS is aborting forcibly**
+
+Does thread dump on stdout on abort.
+
+
+---
+
+* [HBASE-21732](https://issues.apache.org/jira/browse/HBASE-21732) | *Critical* | **Should call toUpperCase before using Enum.valueOf in some methods for ColumnFamilyDescriptor**
+
+Now all the Enum configs in ColumnFamilyDescriptor can accept lower case config value.
+
+
+---
+
+* [HBASE-21712](https://issues.apache.org/jira/browse/HBASE-21712) | *Minor* | **Make submit-patch.py python3 compatible**
+
+Python3 support was added to dev-support/submit-patch.py. To install newly required dependencies run \`pip install -r dev-support/python-requirements.txt\` command.
+
+
+---
+
+* [HBASE-21657](https://issues.apache.org/jira/browse/HBASE-21657) | *Major* | **PrivateCellUtil#estimatedSerializedSizeOf has been the bottleneck in 100% scan case.**
+
+In HBASE-21657, I simplified the path of estimatedSerialiedSize() & estimatedSerialiedSizeOfCell() by moving the general getSerializedSize()
+and heapSize() from ExtendedCell to Cell interface. The patch also included some other improvments:
+
+1. For 99% of case, our cells has no tags, so let the HFileScannerImpl just return the NoTagsByteBufferKeyValue if no tags, which means we can save
+ lots of cpu time when sending no tags cell to rpc because can just return the length instead of getting the serialize size by caculating offset/length
+ of each fields(row/cf/cq..)
+2. Move the subclass's getSerializedSize implementation from ExtendedCell to their own class, which mean we did not need to call ExtendedCell's
+ getSerialiedSize() firstly, then forward to subclass's getSerializedSize(withTags).
+3. Give a estimated result arraylist size for avoiding the frequent list extension when in a big scan, now we estimate the array size as min(scan.rows, 512).
+ it's also help a lot.
+
+We gain almost ~40% throughput improvement in 100% scan case for branch-2 (cacheHitRatio~100%)[1], it's a good thing. While it's a incompatible change in
+some case, such as if the upstream user implemented their own Cells, although it's rare but can happen, then their compile will be error.
+
+
+---
+
+* [HBASE-21647](https://issues.apache.org/jira/browse/HBASE-21647) | *Major* | **Add status track for splitting WAL tasks**
+
+Adds task monitor that shows ServerCrashProcedure progress in UI.
+
+
+---
+
+* [HBASE-21652](https://issues.apache.org/jira/browse/HBASE-21652) | *Major* | **Refactor ThriftServer making thrift2 server inherited from thrift1 server**
+
+Before this issue, thrift1 server and thrift2 server are totally different servers. If a new feature is added to thrift1 server, thrfit2 server have to make the same change to support it(e.g. authorization). After this issue, thrift2 server is inherited from thrift1, thrift2 server now have all the features thrift1 server has(e.g http support, which thrift2 server doesn't have before). The way to start thrift1 or thrift2 server remain the same after this issue.
+
+
+---
+
+* [HBASE-21661](https://issues.apache.org/jira/browse/HBASE-21661) | *Major* | **Provide Thrift2 implementation of Table/Admin**
+
+ThriftAdmin/ThriftTable are implemented based on Thrift2. With ThriftAdmin/ThriftTable, People can use thrift2 protocol just like HTable/HBaseAdmin.
+Example of using ThriftConnection
+Configuration conf = HBaseConfiguration.create();
+conf.set(ClusterConnection.HBASE\_CLIENT\_CONNECTION\_IMPL,ThriftConnection.class.getName());
+Connection conn = ConnectionFactory.createConnection(conf);
+Table table = conn.getTable(tablename)
+It is just like a normal Connection, similar use experience with the default ConnectionImplementation
+
+
+---
+
+* [HBASE-21618](https://issues.apache.org/jira/browse/HBASE-21618) | *Critical* | **Scan with the same startRow(inclusive=true) and stopRow(inclusive=false) returns one result**
+
+There was a bug when scan with the same startRow(inclusive=true) and stopRow(inclusive=false). The old incorrect behavior is return one result. After this fix, the new correct behavior is return nothing.
+
+
+---
+
+* [HBASE-21159](https://issues.apache.org/jira/browse/HBASE-21159) | *Major* | **Add shell command to switch throttle on or off**
+
+Support enable or disable rpc throttle when hbase quota is enabled. If hbase quota is enabled, rpc throttle is enabled by default. When disable rpc throttle, HBase will not throttle any request. Use the following commands to switch rpc throttle : enable\_rpc\_throttle / disable\_rpc\_throttle.
+
+
+---
+
+* [HBASE-21659](https://issues.apache.org/jira/browse/HBASE-21659) | *Minor* | **Avoid to load duplicate coprocessors in system config and table descriptor**
+
+Add a new configuration "hbase.skip.load.duplicate.table.coprocessor". The default value is false to keep compatible with the old behavior. Config it true to skip load duplicate table coprocessor.
+
+
+---
+
+* [HBASE-21650](https://issues.apache.org/jira/browse/HBASE-21650) | *Major* | **Add DDL operation and some other miscellaneous to thrift2**
+
+Added DDL operations and some other structure definition to thrift2. Methods added:
+create/modify/addColumnFamily/deleteColumnFamily/modifyColumnFamily/enable/disable/truncate/delete table
+create/modify/delete namespace
+get(list)TableDescriptor(s)/get(list)NamespaceDescirptor(s)
+tableExists/isTableEnabled/isTableDisabled/isTableAvailabe
+And some class definitions along with those methods
+
+
+---
+
+* [HBASE-21643](https://issues.apache.org/jira/browse/HBASE-21643) | *Major* | **Introduce two new region coprocessor method and deprecated postMutationBeforeWAL**
+
+Deprecated region coprocessor postMutationBeforeWAL and introduce two new region coprocessor postIncrementBeforeWAL and postAppendBeforeWAL instead.
+
+
+---
+
+* [HBASE-21635](https://issues.apache.org/jira/browse/HBASE-21635) | *Major* | **Use maven enforcer to ban imports from illegal packages**
+
+Use de.skuzzle.enforcer.restrict-imports-enforcer-rule extension for maven enforcer plugin to ban illegal imports at compile time. Now if you use illegal imports, for example, import com.google.common.\*, there will be a compile error, instead of a checkstyle warning.
+
+
+---
+
+* [HBASE-21401](https://issues.apache.org/jira/browse/HBASE-21401) | *Critical* | **Sanity check when constructing the KeyValue**
+
+Add a sanity check when constructing KeyValue from a byte[]. we use the constructor when we're reading kv from socket or HFIle or WAL(replication). the santiy check isn't designed for discovering the bits corruption in network transferring or disk IO. It is designed to detect bugs inside HBase in advance. and HBASE-21459 indicated that there's extremely small performance loss for diff kinds of keyvalue.
+
+
+---
+
+* [HBASE-21554](https://issues.apache.org/jira/browse/HBASE-21554) | *Minor* | **Show replication endpoint classname for replication peer on master web UI**
+
+The replication UI on master will show the replication endpoint classname.
+
+
+---
+
+* [HBASE-21549](https://issues.apache.org/jira/browse/HBASE-21549) | *Major* | **Add shell command for serial replication peer**
+
+Add a SERIAL flag for add\_peer command to identifiy whether or not the replication peer is a serial replication peer. The default serial flag is false.
+
+
+---
+
+* [HBASE-21453](https://issues.apache.org/jira/browse/HBASE-21453) | *Major* | **Convert ReadOnlyZKClient to DEBUG instead of INFO**
+
+Log level of ReadOnlyZKClient moved to debug.
+
+
+---
+
+* [HBASE-21283](https://issues.apache.org/jira/browse/HBASE-21283) | *Minor* | **Add new shell command 'rit' for listing regions in transition**
+
+<!-- markdown -->
+# HBASE 2.2.0 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | *Major* | **Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements**
+
+Moving IA.Public class LossyCounting to IA.Private.
+
+
+---
+
+* [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | *Major* | **Update hadoop check versions for hadoop3 in hbase-personality**
+
+Add hadoop 3.0.3, 3.1.1 3.1.2 in our hadoop check jobs.
+
+
+---
+
+* [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | *Major* | **Dump replication queue should show list of wal files ordered chronologically**
+
+The DumpReplicationQueues tool will now list replication queues sorted in chronological order.
+
+
+---
+
+* [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | *Minor* | **Formatting issues in administration section of book**
+
+Fixes a formatting issue in the administration section of the book, where listing indentation were a little bit off.
+
+
+---
+
+* [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | *Major* | **Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks**
+
+Now the default hadoop-two.version has been changed to 2.8.5, and all hadoop versions before 2.8.2(exclude) will not be supported any more.
+
+
+---
+
+* [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | *Trivial* | **Remove extra/useless +**
+
+Removed extra + in HRegion, HStore and LoadIncrementalHFiles for branch-2 and HRegion and HStore for branch-1.
+
+
+---
+
+* [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | *Trivial* | **Fix completebulkload usage instructions**
+
+Added completebulkload short name for BulkLoadHFilesTool to bin/hbase.
+
+
+---
+
+* [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | *Major* | **Upgrade com.yammer.metrics dependency**
+
+Updated metrics core from 3.2.1 to 3.2.6.
+
+
+---
+
+* [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | *Minor* | **Change rubocop configuration for method length**
+
+The rubocop definition for the maximum method length was set to 75.
+
+
+---
+
+* [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | *Minor* | **Fix Markdown for "Voting on Release Candidates" in book**
+
+Fixes the formatting of the "Voting on Release Candidates" to actually show the quote and code formatting of the RAT check.
+
+
+---
+
+* [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | *Minor* | **Change rubocop config for max line length of 100**
+
+The rubocop configuration in the hbase-shell module now allows a line length with 100 characters, instead of 80 as before. For everything before 2.1.5 this change introduces rubocop itself.
+
+
+---
+
+* [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | *Minor* | **Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS**
+
+This change allows the system and superusers to initiate compactions, even when a space quota violation policy disallows compactions from happening. The original intent behind disallowing of compactions was to prevent end-user compactions from creating undue I/O load, not disallowing \*any\* compaction in the system.
+
+
+---
+
+* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
+
+Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
+
+
+---
+
+* [HBASE-22155](https://issues.apache.org/jira/browse/HBASE-22155) | *Major* | **Move 2.2.0 on to hbase-thirdparty-2.2.0**
+
+ Updates libs used internally by hbase via hbase-thirdparty as follows:
+
+ gson 2.8.1 -\\\> 2.8.5
+ guava 22.0 -\\\> 27.1-jre
+ pb 3.5.1 -\\\> 3.7.0
+ netty 4.1.17 -\\\> 4.1.34
+ commons-collections4 4.1 -\\\> 4.3
+
+
+---
+
+* [HBASE-22178](https://issues.apache.org/jira/browse/HBASE-22178) | *Major* | **Introduce a createTableAsync with TableDescriptor method in Admin**
+
+Introduced
+
+Future\<Void\> createTableAsync(TableDescriptor);
+
+
+---
+
+* [HBASE-22108](https://issues.apache.org/jira/browse/HBASE-22108) | *Major* | **Avoid passing null in Admin methods**
+
+Introduced these methods:
+void move(byte[]);
+void move(byte[], ServerName);
+Future\<Void\> splitRegionAsync(byte[]);
+
+These methods are deprecated:
+void move(byte[], byte[])
+
+
+---
+
+* [HBASE-22152](https://issues.apache.org/jira/browse/HBASE-22152) | *Major* | **Create a jenkins file for yetus to processing GitHub PR**
+
+Add a new jenkins file for running pre commit check for GitHub PR.
+
+
+---
+
+* [HBASE-22007](https://issues.apache.org/jira/browse/HBASE-22007) | *Major* | **Add restoreSnapshot and cloneSnapshot with acl methods in AsyncAdmin**
+
+Add cloneSnapshot/restoreSnapshot with acl methods in AsyncAdmin.
+
+
+---
+
+* [HBASE-22123](https://issues.apache.org/jira/browse/HBASE-22123) | *Minor* | **REST gateway reports Insufficient permissions exceptions as 404 Not Found**
+
+When insufficient permissions, you now get:
+
+HTTP/1.1 403 Forbidden
+
+on the HTTP side, and in the message
+
+Forbidden
+org.apache.hadoop.hbase.security.AccessDeniedException: org.apache.hadoop.hbase.security.AccessDeniedException: Insufficient permissions for user ‘myuser',action: get, tableName:mytable, family:cf.
+at org.apache.ranger.authorization.hbase.RangerAuthorizationCoprocessor.authorizeAccess(RangerAuthorizationCoprocessor.java:547)
+and the rest of the ADE stack
+
+
+---
+
+* [HBASE-22100](https://issues.apache.org/jira/browse/HBASE-22100) | *Minor* | **False positive for error prone warnings in pre commit job**
+
+Now we will sort the javac WARNING/ERROR before generating diff in pre-commit so we can get a stable output for the error prone. The downside is that we just sort the output lexicographically so the line number will also be sorted lexicographically, which is a bit strange to human.
+
+
+---
+
+* [HBASE-22057](https://issues.apache.org/jira/browse/HBASE-22057) | *Major* | **Impose upper-bound on size of ZK ops sent in a single multi()**
+
+Exposes a new configuration property "zookeeper.multi.max.size" which dictates the maximum size of deletes that HBase will make to ZooKeeper in a single RPC. This property defaults to 1MB, which should fall beneath the default ZooKeeper limit of 2MB, controlled by "jute.maxbuffer".
+
+
+---
+
+* [HBASE-22052](https://issues.apache.org/jira/browse/HBASE-22052) | *Major* | **pom cleaning; filter out jersey-core in hadoop2 to match hadoop3 and remove redunant version specifications**
+
+<!-- markdown -->
+Fixed awkward dependency issue that prevented site building.
+
+#### note specific to HBase 2.1.4
+HBase 2.1.4 shipped with an early version of this fix that incorrectly altered the libraries included in our binary assembly for using Apache Hadoop 2.7 (the current build default Hadoop version for 2.1.z). For folks running out of the box against a Hadoop 2.7 cluster (or folks who skip the installation step of [replacing the bundled Hadoop libraries](http://hbase.apache.org/book.html#hadoop)) this will result in a failure at Region Server startup due to a missing class definition. e.g.:
+```
+2019-03-27 09:02:05,779 ERROR [main] regionserver.HRegionServer: Failed construction RegionServer
+java.lang.NoClassDefFoundError: org/apache/htrace/SamplerBuilder
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:644)
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:628)
+ at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
+ at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)
+ at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:93)
+ at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2701)
+ at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2683)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:372)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:171)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:356)
+ at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getRootDir(CommonFSUtils.java:362)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.isValidWALRootDir(CommonFSUtils.java:411)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getWALRootDir(CommonFSUtils.java:387)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.initializeFileSystem(HRegionServer.java:704)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.<init>(HRegionServer.java:613)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
+ at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
+ at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.constructRegionServer(HRegionServer.java:3029)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.start(HRegionServerCommandLine.java:63)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.run(HRegionServerCommandLine.java:87)
+ at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
+ at org.apache.hadoop.hbase.util.ServerCommandLine.doMain(ServerCommandLine.java:149)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.main(HRegionServer.java:3047)
+Caused by: java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
+ at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
+ at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
+ ... 26 more
+
+```
+
+Workaround via any _one_ of the following:
+* If you are running against a Hadoop cluster that is 2.8+, ensure you replace the Hadoop libaries in the default binary assembly with those for your version.
+* If you are running against a Hadoop cluster that is 2.8+, build the binary assembly from the source release while specifying your Hadoop version.
+* If you are running against a Hadoop cluster that is a supported 2.7 release, ensure the `hadoop` executable is in the `PATH` seen at Region Server startup and that you are not using the `HBASE_DISABLE_HADOOP_CLASSPATH_LOOKUP` bypass.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers via the HBASE_CLASSPATH environment variable.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers by copying it into the directory `${HBASE_HOME}/lib/client-facing-thirdparty/`.
+
+
+---
+
+* [HBASE-22065](https://issues.apache.org/jira/browse/HBASE-22065) | *Major* | **Add listTableDescriptors(List\<TableName\>) method in AsyncAdmin**
+
+Add a listTableDescriptors(List\<TableName\>) method in the AsyncAdmin interface, to align with the Admin interface.
+
+
+---
+
+* [HBASE-22040](https://issues.apache.org/jira/browse/HBASE-22040) | *Major* | **Add mergeRegionsAsync with a List of region names method in AsyncAdmin**
+
+Add a mergeRegionsAsync(byte[][], boolean) method in the AsyncAdmin interface.
+
+Instead of using assert, now we will throw IllegalArgumentException when you want to merge less than 2 regions at client side. And also, at master side, instead of using assert, now we will throw DoNotRetryIOException if you want merge more than 2 regions, since we only support merging two regions at once for now.
+
+
+---
+
+* [HBASE-22039](https://issues.apache.org/jira/browse/HBASE-22039) | *Major* | **Should add the synchronous parameter for the XXXSwitch method in AsyncAdmin**
+
+Add drainXXX parameter for balancerSwitch/splitSwitch/mergeSwitch methods in the AsyncAdmin interface, which has the same meaning with the synchronous parameter for these methods in the Admin interface.
+
+
+---
+
+* [HBASE-21810](https://issues.apache.org/jira/browse/HBASE-21810) | *Major* | **bulkload support set hfile compression on client**
+
+bulkload (HFileOutputFormat2) support config the compression on client ,you can set the job configuration "hbase.mapreduce.hfileoutputformat.compression" override the auto-detection of the target table's compression
+
+
+---
+
+* [HBASE-22000](https://issues.apache.org/jira/browse/HBASE-22000) | *Major* | **Deprecated isTableAvailable with splitKeys**
+
+Deprecated AsyncTable.isTableAvailable(TableName, byte[][]).
+
+
+---
+
+* [HBASE-21871](https://issues.apache.org/jira/browse/HBASE-21871) | *Major* | **Support to specify a peer table name in VerifyReplication tool**
+
+After HBASE-21871, we can specify a peer table name with --peerTableName in VerifyReplication tool like the following:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable 5 TestTable
+
+In addition, we can compare any 2 tables in any remote clusters with specifying both peerId and --peerTableName.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable zk1,zk2,zk3:2181/hbase TestTable
+
+
+---
+
+* [HBASE-15728](https://issues.apache.org/jira/browse/HBASE-15728) | *Major* | **Add remaining per-table region / store / flush / compaction related metrics**
+
+Adds below flush, split, and compaction metrics
+
+ + // split related metrics
+ + private MutableFastCounter splitRequest;
+ + private MutableFastCounter splitSuccess;
+ + private MetricHistogram splitTimeHisto;
+ +
+ + // flush related metrics
+ + private MetricHistogram flushTimeHisto;
+ + private MetricHistogram flushMemstoreSizeHisto;
+ + private MetricHistogram flushOutputSizeHisto;
+ + private MutableFastCounter flushedMemstoreBytes;
+ + private MutableFastCounter flushedOutputBytes;
+ +
+ + // compaction related metrics
+ + private MetricHistogram compactionTimeHisto;
+ + private MetricHistogram compactionInputFileCountHisto;
+ + private MetricHistogram compactionInputSizeHisto;
+ + private MetricHistogram compactionOutputFileCountHisto;
+ + private MetricHistogram compactionOutputSizeHisto;
+ + private MutableFastCounter compactedInputBytes;
+ + private MutableFastCounter compactedOutputBytes;
+ +
+ + private MetricHistogram majorCompactionTimeHisto;
+ + private MetricHistogram majorCompactionInputFileCountHisto;
+ + private MetricHistogram majorCompactionInputSizeHisto;
+ + private MetricHistogram majorCompactionOutputFileCountHisto;
+ + private MetricHistogram majorCompactionOutputSizeHisto;
+ + private MutableFastCounter majorCompactedInputBytes;
+ + private MutableFastCounter majorCompactedOutputBytes;
+
+
+---
+
+* [HBASE-20886](https://issues.apache.org/jira/browse/HBASE-20886) | *Critical* | **[Auth] Support keytab login in hbase client**
+
+From 2.2.0, hbase supports client login via keytab. To use this feature, client should specify \`hbase.client.keytab.file\` and \`hbase.client.keytab.principal\` in hbase-site.xml, then the connection will contain the needed credentials which be renewed periodically to communicate with kerberized hbase cluster.
+
+
+---
+
+* [HBASE-21410](https://issues.apache.org/jira/browse/HBASE-21410) | *Major* | **A helper page that help find all problematic regions and procedures**
+
+After HBASE-21410, we add a helper page to Master UI. This helper page is mainly to help HBase operator quickly found all regions and pids that are get stuck.
+There are 2 entries to get in this page.
+One is showing in the Regions in Transition section, it made "num region(s) in transition" a link that you can click and check all regions in transition and their related procedure IDs.
+The other one is showing in the table details section, it made the number of CLOSING or OPENING regions a link, which you can click and check regions and related procedure IDs of CLOSING or OPENING regions of a certain table.
+In this helper page, not only you can see all regions and related procedures, there are 2 buttons at the top which will show these regions or procedure IDs in text format. This is mainly aim to help operator to easily copy and paste all problematic procedure IDs and encoded region names to HBCK2's command line, by which we HBase operator can bypass these procedures or assign these regions.
+
+
+---
+
+* [HBASE-21588](https://issues.apache.org/jira/browse/HBASE-21588) | *Major* | **Procedure v2 wal splitting implementation**
+
+After HBASE-21588, we introduce a new way to do WAL splitting coordination by procedure framework. This can simplify the process of WAL splitting and no need to connect zookeeper any more.
+During ServerCrashProcedure, it will create a SplitWALProcedure for each WAL that need to split. Then each SplitWALProcedure will spawn a SplitWALRemoteProcedure to send the request to regionserver.
+At the RegionServer side, whole process is handled by SplitWALCallable. It split the WAL and return the result to master.
+According to my test, this patch has a better performance as the number of WALs that need to split increase. And it can relieve the pressure on zookeeper.
+
+
+---
+
+* [HBASE-20734](https://issues.apache.org/jira/browse/HBASE-20734) | *Major* | **Colocate recovered edits directory with hbase.wal.dir**
+
+Previously the recovered.edits directory was under the root directory. This JIRA moves the recovered.edits directory to be under the hbase.wal.dir if set. It also adds a check for any recovered.edits found under the root directory for backwards compatibility. This gives improvements when a faster media(like SSD) or more local FileSystem is used for the hbase.wal.dir than the root dir.
+
+
+---
+
+* [HBASE-20401](https://issues.apache.org/jira/browse/HBASE-20401) | *Minor* | **Make \`MAX\_WAIT\` and \`waitIfNotFinished\` in CleanerContext configurable**
+
+When oldwals (and hfile) cleaner cleans stale wals (and hfiles), it will periodically check and wait the clean results from filesystem, the total wait time will be no more than a max time.
+
+The periodically wait and check configurations are hbase.oldwals.cleaner.thread.check.interval.msec (default is 500 ms) and hbase.regionserver.hfilecleaner.thread.check.interval.msec (default is 1000 ms).
+
+Meanwhile, The max time configurations are hbase.oldwals.cleaner.thread.timeout.msec and hbase.regionserver.hfilecleaner.thread.timeout.msec, they are set to 60 seconds by default.
+
+All support dynamic configuration.
+
+e.g. in the oldwals cleaning scenario, one may consider tuning hbase.oldwals.cleaner.thread.timeout.msec and hbase.oldwals.cleaner.thread.check.interval.msec
+
+1. While deleting a oldwal never complete (strange but possible), then delete file task needs to wait for a max of 60 seconds. Here, 60 seconds might be too long, or the opposite way is to increase more than 60 seconds in the use cases of slow file delete.
+2. The check and wait of a file delete is set to default in the period of 500 milliseconds, one might want to tune this checking period to a short interval to check more frequently or to a longer interval to avoid checking too often to manage their delete file task checking period (the longer interval may be use to avoid checking too fast while using a high latency storage).
+
+
+---
+
+* [HBASE-21481](https://issues.apache.org/jira/browse/HBASE-21481) | *Major* | **[acl] Superuser's permissions should not be granted or revoked by any non-su global admin**
+
+HBASE-21481 improves the quality of access control, by strengthening the protection of super users's privileges.
+
+
+---
+
+* [HBASE-21082](https://issues.apache.org/jira/browse/HBASE-21082) | *Critical* | **Reimplement assign/unassign related procedure metrics**
+
+Now we have four types of RIT procedure metrics, assign, unassign, move, reopen. The meaning of assign/unassign is changed, as we will not increase the unassign metric and then the assign metric when moving a region.
+Also introduced two new procedure metrics, open and close, which are used to track the open/close region calls to region server. We may send open/close multiple times to finish a RIT since we may retry multiple times.
+
+
+---
+
+* [HBASE-20724](https://issues.apache.org/jira/browse/HBASE-20724) | *Critical* | **Sometimes some compacted storefiles are still opened after region failover**
+
+Problem: This is an old problem since HBASE-2231. The compaction event marker was only writed to WAL. But after flush, the WAL may be archived, which means an useful compaction event marker be deleted, too. So the compacted store files cannot be archived when region open and replay WAL.
+
+Solution: After this jira, the compaction event tracker will be writed to HFile. When region open and load store files, read the compaction evnet tracker from HFile and archive the compacted store files which still exist.
+
+
+---
+
+* [HBASE-21820](https://issues.apache.org/jira/browse/HBASE-21820) | *Major* | **Implement CLUSTER quota scope**
+
+HBase contains two quota scopes: MACHINE and CLUSTER. Before this patch, set quota operations did not expose scope option to client api and use MACHINE as default, CLUSTER scope can not be set and used.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+
+This issue implements CLUSTER scope in a simple way: For user, namespace, user over namespace quota, use [ClusterLimit / RSNum] as machine limit. For table and user over table quota, use [ClusterLimit / TotalTableRegionNum \* MachineTableRegionNum] as machine limit.
+After this patch, user can set CLUSTER scope quota, but MACHINE is still default if user ignore scope.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> MACHINE
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> CLUSTER
+
+
+---
+
+* [HBASE-21057](https://issues.apache.org/jira/browse/HBASE-21057) | *Minor* | **upgrade to latest spotbugs**
+
+Change spotbugs version to 3.1.11.
+
+
+---
+
+* [HBASE-21922](https://issues.apache.org/jira/browse/HBASE-21922) | *Major* | **BloomContext#sanityCheck may failed when use ROWPREFIX\_DELIMITED bloom filter**
+
+Remove bloom filter type ROWPREFIX\_DELIMITED. May add it back when find a better solution.
+
+
+---
+
+* [HBASE-21783](https://issues.apache.org/jira/browse/HBASE-21783) | *Major* | **Support exceed user/table/ns throttle quota if region server has available quota**
+
+Support enable or disable exceed throttle quota. Exceed throttle quota means, user can over consume user/namespace/table quota if region server has additional available quota because other users don't consume at the same time.
+Use the following shell commands to enable/disable exceed throttle quota: enable\_exceed\_throttle\_quota
+disable\_exceed\_throttle\_quota
+There are two limits when enable exceed throttle quota:
+1. Must set at least one read and one write region server throttle quota;
+2. All region server throttle quotas must be in seconds time unit. Because once previous requests exceed their quota and consume region server quota, quota in other time units may be refilled in a long time, this may affect later requests.
+
+
+---
+
+* [HBASE-20587](https://issues.apache.org/jira/browse/HBASE-20587) | *Major* | **Replace Jackson with shaded thirdparty gson**
+
+Remove jackson dependencies from most hbase modules except hbase-rest, use shaded gson instead. The output json will be a bit different since jackson can use getter/setter, but gson will always use the fields.
+
+
+---
+
+* [HBASE-21928](https://issues.apache.org/jira/browse/HBASE-21928) | *Major* | **Deprecated HConstants.META\_QOS**
+
+Mark HConstants.META\_QOS as deprecated. It is for internal use only, which is the highest priority. You should not try to set a priority greater than or equal to this value, although it is no harm but also useless.
+
+
+---
+
+* [HBASE-17942](https://issues.apache.org/jira/browse/HBASE-17942) | *Major* | **Disable region splits and merges per table**
+
+This patch adds the ability to disable split and/or merge for a table (By default, split and merge are enabled for a table).
+
+
+---
+
+* [HBASE-21636](https://issues.apache.org/jira/browse/HBASE-21636) | *Major* | **Enhance the shell scan command to support missing scanner specifications like ReadType, IsolationLevel etc.**
+
+Allows shell to set Scan options previously not exposed. See additions as part of the scan help by typing following hbase shell:
+
+hbase\> help 'scan'
+
+
+---
+
+* [HBASE-21201](https://issues.apache.org/jira/browse/HBASE-21201) | *Major* | **Support to run VerifyReplication MR tool without peerid**
+
+We can specify peerQuorumAddress instead of peerId in VerifyReplication tool. So it no longer requires peerId to be setup when using this tool.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication zk1,zk2,zk3:2181/hbase testTable
+
+
+---
+
+* [HBASE-21838](https://issues.apache.org/jira/browse/HBASE-21838) | *Major* | **Create a special ReplicationEndpoint just for verifying the WAL entries are fine**
+
+Introduce a VerifyWALEntriesReplicationEndpoint which replicates nothing but only verifies if all the cells are valid.
+It can be used to capture bugs for writing WAL, as most times we will not read the WALs again after writing it if there are no region server crashes.
+
+
+---
+
+* [HBASE-21727](https://issues.apache.org/jira/browse/HBASE-21727) | *Minor* | **Simplify documentation around client timeout**
+
+Deprecated HBaseConfiguration#getInt(Configuration, String, String, int) method and removed it from 3.0.0 version.
+
+
+---
+
+* [HBASE-21764](https://issues.apache.org/jira/browse/HBASE-21764) | *Major* | **Size of in-memory compaction thread pool should be configurable**
+
+Introduced an new config key in this issue: hbase.regionserver.inmemory.compaction.pool.size. the default value would be 10. you can configure this to set the pool size of in-memory compaction pool. Note that all memstores in one region server will share the same pool, so if you have many regions in one region server, you need to set this larger to compact faster for better read performance.
+
+
+---
+
+* [HBASE-21684](https://issues.apache.org/jira/browse/HBASE-21684) | *Major* | **Throw DNRIOE when connection or rpc client is closed**
+
+Make StoppedRpcClientException extend DoNotRetryIOException.
+
+
+---
+
+* [HBASE-21739](https://issues.apache.org/jira/browse/HBASE-21739) | *Major* | **Move grant/revoke from regionserver to master**
+
+To implement user permission control in Precedure V2, move grant and revoke method from AccessController to master firstly.
+Mark AccessController#grant and AccessController#revoke as deprecated and please use Admin#grant and Admin#revoke instead.
+
+
+---
+
+* [HBASE-21791](https://issues.apache.org/jira/browse/HBASE-21791) | *Blocker* | **Upgrade thrift dependency to 0.12.0**
+
+IMPORTANT: Due to security issues, all users who use hbase thrift should avoid using releases which do not have this fix.
+
+The effect releases are:
+2.1.x: 2.1.2 and below
+2.0.x: 2.0.4 and below
+1.x: 1.4.x and below
+
+If you are using the effect releases above, please consider upgrading to a newer release ASAP.
+
+
+---
+
+* [HBASE-21792](https://issues.apache.org/jira/browse/HBASE-21792) | *Major* | **Mark HTableMultiplexer as deprecated and remove it in 3.0.0**
+
+HTableMultiplexer exposes the implementation class, and it is incomplete, so we mark it as deprecated and remove it in 3.0.0 release.
+
+There is no direct replacement for HTableMultiplexer, please use BufferedMutator if you want to batch mutations to a table.
+
+
+---
+
+* [HBASE-21782](https://issues.apache.org/jira/browse/HBASE-21782) | *Major* | **LoadIncrementalHFiles should not be IA.Public**
+
+Introduce a BulkLoadHFiles interface which is marked as IA.Public, for doing bulk load programmatically.
+Introduce a BulkLoadHFilesTool which extends BulkLoadHFiles, and is marked as IA.LimitedPrivate(TOOLS), for using from command line.
+The old LoadIncrementalHFiles is deprecated and will be removed in 3.0.0.
+
+
+---
+
+* [HBASE-21762](https://issues.apache.org/jira/browse/HBASE-21762) | *Major* | **Move some methods in ClusterConnection to Connection**
+
+Move the two getHbck method from ClusterConnection to Connection, and mark the methods as IA.LimitedPrivate(HBCK), as ClusterConnection is IA.Private and should not be depended by HBCK2.
+
+Add a clearRegionLocationCache method in Connection to clear the region location cache for all the tables. As in RegionLocator, most of the methods have a 'reload' parameter, which implicitly tells user that we have a region location cache, so adding a method to clear the cache is fine.
+
+
+---
+
+* [HBASE-21713](https://issues.apache.org/jira/browse/HBASE-21713) | *Major* | **Support set region server throttle quota**
+
+Support set region server rpc throttle quota which represents the read/write ability of region servers and throttles when region server's total requests exceeding the limit.
+
+Use the following shell command to set RS quota:
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', THROTTLE\_TYPE =\> WRITE, LIMIT =\> '20000req/sec'
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', LIMIT =\> NONE
+"all" represents the throttle quota of all region servers and setting specified region server quota isn't supported currently.
+
+
+---
+
+* [HBASE-21689](https://issues.apache.org/jira/browse/HBASE-21689) | *Minor* | **Make table/namespace specific current quota info available in shell(describe\_namespace & describe)**
+
+In shell commands "describe\_namespace" and "describe", which are used to see the descriptors of the namespaces and tables respectively, quotas set on that particular namespace/table will also be printed along.
+
+
+---
+
+* [HBASE-17370](https://issues.apache.org/jira/browse/HBASE-17370) | *Major* | **Fix or provide shell scripts to drain and decommission region server**
+
+Adds shell support for the following:
+- List decommissioned/draining region servers
+- Decommission a list of region servers, optionally offload corresponding regions
+- Recommission a region server, optionally load a list of passed regions
+
+
+---
+
+* [HBASE-21734](https://issues.apache.org/jira/browse/HBASE-21734) | *Major* | **Some optimization in FilterListWithOR**
+
+After HBASE-21620, the filterListWithOR has been a bit slow because we need to merge each sub-filter's RC , while before HBASE-21620, we will skip many RC merging, but the logic was wrong. So here we choose another way to optimaze the performance: removing the KeyValueUtil#toNewKeyCell.
+Anoop Sam John suggested that the KeyValueUtil#toNewKeyCell can save some GC before because if we copy key part of cell into a single byte[], then the block the cell refering won't be refered by the filter list any more, the upper layer can GC the data block quickly. while after HBASE-21620, we will update the prevCellList for every encountered cell now, so the lifecycle of cell in prevCellList for FilterList will be quite shorter. so just use the cell ref for saving cpu.
+BTW, we removed all the arrays streams usage in filter list, because it's also quite time-consuming in our test.
+
+
+---
+
+* [HBASE-21738](https://issues.apache.org/jira/browse/HBASE-21738) | *Critical* | **Remove all the CSLM#size operation in our memstore because it's an quite time consuming.**
+
+We found the memstore snapshotting would cost much time because of calling the time-consuming ConcurrentSkipListMap#Size, it would make the p999 latency spike happen. So in this issue, we remove all ConcurrentSkipListMap#size in memstore by counting the cellsCount in MemstoreSizeing. As the issue described, the p999 latency spike was mitigated.
+
+
+---
+
+* [HBASE-21034](https://issues.apache.org/jira/browse/HBASE-21034) | *Major* | **Add new throttle type: read/write capacity unit**
+
+Provides a new throttle type: capacity unit. One read/write/request capacity unit represents that read/write/read+write up to 1K data. If data size is more than 1K, then consume additional capacity units.
+
+Use shell command to set capacity unit(CU):
+set\_quota TYPE =\> THROTTLE, THROTTLE\_TYPE =\> WRITE, USER =\> 'u1', LIMIT =\> '10CU/sec'
+
+Use the "hbase.quota.read.capacity.unit" property to set the data size of one read capacity unit in bytes, the default value is 1K. Use the "hbase.quota.write.capacity.unit" property to set the data size of one write capacity unit in bytes, the default value is 1K.
+
+
+---
+
+* [HBASE-21595](https://issues.apache.org/jira/browse/HBASE-21595) | *Minor* | **Print thread's information and stack traces when RS is aborting forcibly**
+
+Does thread dump on stdout on abort.
+
+
+---
+
+* [HBASE-21732](https://issues.apache.org/jira/browse/HBASE-21732) | *Critical* | **Should call toUpperCase before using Enum.valueOf in some methods for ColumnFamilyDescriptor**
+
+Now all the Enum configs in ColumnFamilyDescriptor can accept lower case config value.
+
+
+---
+
+* [HBASE-21712](https://issues.apache.org/jira/browse/HBASE-21712) | *Minor* | **Make submit-patch.py python3 compatible**
+
+Python3 support was added to dev-support/submit-patch.py. To install newly required dependencies run \`pip install -r dev-support/python-requirements.txt\` command.
+
+
+---
+
+* [HBASE-21657](https://issues.apache.org/jira/browse/HBASE-21657) | *Major* | **PrivateCellUtil#estimatedSerializedSizeOf has been the bottleneck in 100% scan case.**
+
+In HBASE-21657, I simplified the path of estimatedSerialiedSize() & estimatedSerialiedSizeOfCell() by moving the general getSerializedSize()
+and heapSize() from ExtendedCell to Cell interface. The patch also included some other improvments:
+
+1. For 99% of case, our cells has no tags, so let the HFileScannerImpl just return the NoTagsByteBufferKeyValue if no tags, which means we can save
+ lots of cpu time when sending no tags cell to rpc because can just return the length instead of getting the serialize size by caculating offset/length
+ of each fields(row/cf/cq..)
+2. Move the subclass's getSerializedSize implementation from ExtendedCell to their own class, which mean we did not need to call ExtendedCell's
+ getSerialiedSize() firstly, then forward to subclass's getSerializedSize(withTags).
+3. Give a estimated result arraylist size for avoiding the frequent list extension when in a big scan, now we estimate the array size as min(scan.rows, 512).
+ it's also help a lot.
+
+We gain almost ~40% throughput improvement in 100% scan case for branch-2 (cacheHitRatio~100%)[1], it's a good thing. While it's a incompatible change in
+some case, such as if the upstream user implemented their own Cells, although it's rare but can happen, then their compile will be error.
+
+
+---
+
+* [HBASE-21647](https://issues.apache.org/jira/browse/HBASE-21647) | *Major* | **Add status track for splitting WAL tasks**
+
+Adds task monitor that shows ServerCrashProcedure progress in UI.
+
+
+---
+
+* [HBASE-21652](https://issues.apache.org/jira/browse/HBASE-21652) | *Major* | **Refactor ThriftServer making thrift2 server inherited from thrift1 server**
+
+Before this issue, thrift1 server and thrift2 server are totally different servers. If a new feature is added to thrift1 server, thrfit2 server have to make the same change to support it(e.g. authorization). After this issue, thrift2 server is inherited from thrift1, thrift2 server now have all the features thrift1 server has(e.g http support, which thrift2 server doesn't have before). The way to start thrift1 or thrift2 server remain the same after this issue.
+
+
+---
+
+* [HBASE-21661](https://issues.apache.org/jira/browse/HBASE-21661) | *Major* | **Provide Thrift2 implementation of Table/Admin**
+
+ThriftAdmin/ThriftTable are implemented based on Thrift2. With ThriftAdmin/ThriftTable, People can use thrift2 protocol just like HTable/HBaseAdmin.
+Example of using ThriftConnection
+Configuration conf = HBaseConfiguration.create();
+conf.set(ClusterConnection.HBASE\_CLIENT\_CONNECTION\_IMPL,ThriftConnection.class.getName());
+Connection conn = ConnectionFactory.createConnection(conf);
+Table table = conn.getTable(tablename)
+It is just like a normal Connection, similar use experience with the default ConnectionImplementation
+
+
+---
+
+* [HBASE-21618](https://issues.apache.org/jira/browse/HBASE-21618) | *Critical* | **Scan with the same startRow(inclusive=true) and stopRow(inclusive=false) returns one result**
+
+There was a bug when scan with the same startRow(inclusive=true) and stopRow(inclusive=false). The old incorrect behavior is return one result. After this fix, the new correct behavior is return nothing.
+
+
+---
+
+* [HBASE-21159](https://issues.apache.org/jira/browse/HBASE-21159) | *Major* | **Add shell command to switch throttle on or off**
+
+Support enable or disable rpc throttle when hbase quota is enabled. If hbase quota is enabled, rpc throttle is enabled by default. When disable rpc throttle, HBase will not throttle any request. Use the following commands to switch rpc throttle : enable\_rpc\_throttle / disable\_rpc\_throttle.
+
+
+---
+
+* [HBASE-21659](https://issues.apache.org/jira/browse/HBASE-21659) | *Minor* | **Avoid to load duplicate coprocessors in system config and table descriptor**
+
+Add a new configuration "hbase.skip.load.duplicate.table.coprocessor". The default value is false to keep compatible with the old behavior. Config it true to skip load duplicate table coprocessor.
+
+
+---
+
+* [HBASE-21650](https://issues.apache.org/jira/browse/HBASE-21650) | *Major* | **Add DDL operation and some other miscellaneous to thrift2**
+
+Added DDL operations and some other structure definition to thrift2. Methods added:
+create/modify/addColumnFamily/deleteColumnFamily/modifyColumnFamily/enable/disable/truncate/delete table
+create/modify/delete namespace
+get(list)TableDescriptor(s)/get(list)NamespaceDescirptor(s)
+tableExists/isTableEnabled/isTableDisabled/isTableAvailabe
+And some class definitions along with those methods
+
+
+---
+
+* [HBASE-21643](https://issues.apache.org/jira/browse/HBASE-21643) | *Major* | **Introduce two new region coprocessor method and deprecated postMutationBeforeWAL**
+
+Deprecated region coprocessor postMutationBeforeWAL and introduce two new region coprocessor postIncrementBeforeWAL and postAppendBeforeWAL instead.
+
+
+---
+
+* [HBASE-21635](https://issues.apache.org/jira/browse/HBASE-21635) | *Major* | **Use maven enforcer to ban imports from illegal packages**
+
+Use de.skuzzle.enforcer.restrict-imports-enforcer-rule extension for maven enforcer plugin to ban illegal imports at compile time. Now if you use illegal imports, for example, import com.google.common.\*, there will be a compile error, instead of a checkstyle warning.
+
+
+---
+
+* [HBASE-21401](https://issues.apache.org/jira/browse/HBASE-21401) | *Critical* | **Sanity check when constructing the KeyValue**
+
+Add a sanity check when constructing KeyValue from a byte[]. we use the constructor when we're reading kv from socket or HFIle or WAL(replication). the santiy check isn't designed for discovering the bits corruption in network transferring or disk IO. It is designed to detect bugs inside HBase in advance. and HBASE-21459 indicated that there's extremely small performance loss for diff kinds of keyvalue.
+
+
+---
+
+* [HBASE-21554](https://issues.apache.org/jira/browse/HBASE-21554) | *Minor* | **Show replication endpoint classname for replication peer on master web UI**
+
+The replication UI on master will show the replication endpoint classname.
+
+
+---
+
+* [HBASE-21549](https://issues.apache.org/jira/browse/HBASE-21549) | *Major* | **Add shell command for serial replication peer**
+
+Add a SERIAL flag for add\_peer command to identifiy whether or not the replication peer is a serial replication peer. The default serial flag is false.
+
+
+---
+
+* [HBASE-21453](https://issues.apache.org/jira/browse/HBASE-21453) | *Major* | **Convert ReadOnlyZKClient to DEBUG instead of INFO**
+
+Log level of ReadOnlyZKClient moved to debug.
+
+
+---
+
+* [HBASE-21283](https://issues.apache.org/jira/browse/HBASE-21283) | *Minor* | **Add new shell command 'rit' for listing regions in transition**
+
+<!-- markdown -->
+
+The HBase `shell` now includes a command to list regions currently in transition.
+
+```
+HBase Shell
+Use "help" to get list of supported commands.
+Use "exit" to quit this interactive shell.
+Version 1.5.0-SNAPSHOT, r9bb6d2fa8b760f16cd046657240ebd4ad91cb6de, Mon Oct 8 21:05:50 UTC 2018
+
+hbase(main):001:0> help 'rit'
+List all regions in transition.
+Examples:
+ hbase> rit
+
+hbase(main):002:0> create ...
+0 row(s) in 2.5150 seconds
+=> Hbase::Table - IntegrationTestBigLinkedList
+
+hbase(main):003:0> rit
+0 row(s) in 0.0340 seconds
+
+hbase(main):004:0> unassign '56f0c38c81ae453d19906ce156a2d6a1'
+0 row(s) in 0.0540 seconds
+
+hbase(main):005:0> rit
+IntegrationTestBigLinkedList,L\xCC\xCC\xCC\xCC\xCC\xCC\xCB,1539117183224.56f0c38c81ae453d19906ce156a2d6a1. state=PENDING_CLOSE, ts=Tue Oct 09 20:33:34 UTC 2018 (0s ago), server=null
+1 row(s) in 0.0170 seconds
+```
+
+
+---
+
+* [HBASE-21567](https://issues.apache.org/jira/browse/HBASE-21567) | *Major* | **Allow overriding configs starting up the shell**
+
+Allow passing of -Dkey=value option to shell to override hbase-\* configuration: e.g.:
+
+$ ./bin/hbase shell -Dhbase.zookeeper.quorum=ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org -Draining=false
+...
+hbase(main):001:0\> @shell.hbase.configuration.get("hbase.zookeeper.quorum")
+=\> "ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org"
+hbase(main):002:0\> @shell.hbase.configuration.get("raining")
+=\> "false"
+
+
+---
+
+* [HBASE-21560](https://issues.apache.org/jira/browse/HBASE-21560) | *Major* | **Return a new TableDescriptor for MasterObserver#preModifyTable to allow coprocessor modify the TableDescriptor**
+
+Incompatible change. Allow MasterObserver#preModifyTable to return a new TableDescriptor. And master will use this returned TableDescriptor to modify table.
+
+
+---
+
+* [HBASE-21551](https://issues.apache.org/jira/browse/HBASE-21551) | *Blocker* | **Memory leak when use scan with STREAM at server side**
+
+<!-- markdown -->
+### Summary
+HBase clusters will experience Region Server failures due to out of memory errors due to a leak given any of the following:
+
+* User initiates Scan operations set to use the STREAM reading type
+* User initiates Scan operations set to use the default reading type that read more than 4 * the block size of column families involved in the scan (e.g. by default 4*64KiB)
+* Compactions run
+
+### Root cause
+
+When there are long running scans the Region Server process attempts to optimize access by using a different API geared towards sequential access. Due to an error in HBASE-20704 for HBase 2.0+ the Region Server fails to release related resources when those scans finish. That same optimization path is always used for the HBase internal file compaction process.
+
+### Workaround
+
+Impact for this error can be minimized by setting the config value “hbase.storescanner.pread.max.bytes” to MAX_INT to avoid the optimization for default user scans. Clients should also be checked to ensure they do not pass the STREAM read type to the Scan API. This will have a severe impact on performance for long scans.
+
+Compactions always use this sequential optimized reading mechanism so downstream users will need to periodically restart Region Server roles after compactions have happened.
+
+
+---
+
+* [HBASE-21550](https://issues.apache.org/jira/browse/HBASE-21550) | *Major* | **Add a new method preCreateTableRegionInfos for MasterObserver which allows CPs to modify the TableDescriptor**
+
+Add a new method preCreateTableRegionInfos for MasterObserver, which will be called before creating region infos for the given table, before the preCreateTable method. It allows you to return a new TableDescritor to override the original one. Returns null or throws exception will stop the creation.
+
+
+---
+
+* [HBASE-21492](https://issues.apache.org/jira/browse/HBASE-21492) | *Critical* | **CellCodec Written To WAL Before It's Verified**
+
+After HBASE-21492 the return type of WALCellCodec#getWALCellCodecClass has been changed from String to Class
+
+
+---
+
+* [HBASE-21387](https://issues.apache.org/jira/browse/HBASE-21387) | *Major* | **Race condition surrounding in progress snapshot handling in snapshot cache leads to loss of snapshot files**
+
+To prevent race condition between in progress snapshot (performed by TakeSnapshotHandler) and HFileCleaner which results in data loss, this JIRA introduced mutual exclusion between taking snapshot and running HFileCleaner. That is, at any given moment, either some snapshot can be taken or, HFileCleaner checks hfiles which are not referenced, but not both can be running.
+
+
+---
+
+* [HBASE-21452](https://issues.apache.org/jira/browse/HBASE-21452) | *Major* | **Illegal character in hbase counters group name**
+
+Changes group name of hbase metrics from "HBase Counters" to "HBaseCounters".
+
+
+---
+
+* [HBASE-21443](https://issues.apache.org/jira/browse/HBASE-21443) | *Major* | **[hbase-connectors] Purge hbase-\* modules from core now they've been moved to hbase-connectors**
+
+Parent issue moved hbase-spark\* modules to hbase-connectors. This issue removes hbase-spark\* modules from hbase core repo.
+
+
+---
+
+* [HBASE-21430](https://issues.apache.org/jira/browse/HBASE-21430) | *Major* | **[hbase-connectors] Move hbase-spark\* modules to hbase-connectors repo**
+
+hbase-spark\* modules have been cloned to https://github.com/apache/hbase-connectors All spark connector dev is to happen in that repo from here on out.
+
+Let me file a subtask to remove hbase-spark\* modules from hbase core.
+
+
+---
+
+* [HBASE-21417](https://issues.apache.org/jira/browse/HBASE-21417) | *Critical* | **Pre commit build is broken due to surefire plugin crashes**
+
+Add -Djdk.net.URLClassPath.disableClassPathURLCheck=true when executing surefire plugin.
+
+
+---
+
+* [HBASE-21191](https://issues.apache.org/jira/browse/HBASE-21191) | *Major* | **Add a holding-pattern if no assign for meta or namespace (Can happen if masterprocwals have been cleared).**
+
+Puts master startup into holding pattern if meta is not assigned (previous it would exit). To make progress again, operator needs to inject an assign (Caveats and instruction can be found in HBASE-21035).
+
+
+---
+
+* [HBASE-21322](https://issues.apache.org/jira/browse/HBASE-21322) | *Critical* | **Add a scheduleServerCrashProcedure() API to HbckService**
+
+Adds scheduleServerCrashProcedure to the HbckService.
+
+
+---
+
+* [HBASE-21325](https://issues.apache.org/jira/browse/HBASE-21325) | *Major* | **Force to terminate regionserver when abort hang in somewhere**
+
+Add two new config hbase.regionserver.abort.timeout and hbase.regionserver.abort.timeout.task. If regionserver abort timeout, it will schedule an abort timeout task to run. The default abort task is SystemExitWhenAbortTimeout, which will force to terminate region server when abort timeout. And you can config a special abort timeout task by hbase.regionserver.abort.timeout.task.
+
+
+---
+
+* [HBASE-21215](https://issues.apache.org/jira/browse/HBASE-21215) | *Major* | **Figure how to invoke hbck2; make it easy to find**
+
+Adds to bin/hbase means of invoking hbck2. Pass the new '-j' option on the 'hbck' command with a value of the full path to the HBCK2.jar.
+
+E.g:
+
+$ ./bin/hbase hbck -j ~/checkouts/hbase-operator-tools/hbase-hbck2/target/hbase-hbck2-1.0.0-SNAPSHOT.jar setTableState x ENABLED
+
+
+---
+
+* [HBASE-21372](https://issues.apache.org/jira/browse/HBASE-21372) | *Major* | **Set hbase.assignment.maximum.attempts to Long.MAX**
+
+Retry assigns 'forever' (or until an intervention such as a ServerCrashProcedure).
+
+Previous retry was a maximum of ten times but on failure, handling was an indeterminate.
+
+
+---
+
+* [HBASE-21338](https://issues.apache.org/jira/browse/HBASE-21338) | *Major* | **[balancer] If balancer is an ill-fit for cluster size, it gives little indication**
+
+The description claims the balancer not dynamically configurable but this is an error; it is http://hbase.apache.org/book.html#dyn\_config
+
+Also, if balancer is seen to be cutting out too soon, try setting "hbase.master.balancer.stochastic.runMaxSteps" to true.
+
+Adds cleaner logging around balancer start.
+
+
+---
+
+* [HBASE-21073](https://issues.apache.org/jira/browse/HBASE-21073) | *Major* | **"Maintenance mode" master**
+
+ Instead of being an ephemeral state set by hbck, maintenance mode is now
+ an explicit toggle set by either configuration property or environment
+ variable. In maintenance mode, master will host system tables and not
+ assign any user-space tables to RSs. This gives operators the ability to
+ affect repairs to meta table with fewer moving parts.
+
+
+---
+
+* [HBASE-21335](https://issues.apache.org/jira/browse/HBASE-21335) | *Critical* | **Change the default wait time of HBCK2 tool**
+
+Changed waitTime parameter to lockWait on bypass. Changed default waitTime from 0 -- i.e. wait for ever -- to 1ms so if lock is held, we'll go past it and if override enforce bypass.
+
+
+---
+
+* [HBASE-21291](https://issues.apache.org/jira/browse/HBASE-21291) | *Major* | **Add a test for bypassing stuck state-machine procedures**
+
+bypass will now throw an Exception if passed a lockWait \<= 0; i.e bypass will prevent an operator getting stuck on an entity lock waiting forever (lockWait == 0)
+
+
+---
+
+* [HBASE-21320](https://issues.apache.org/jira/browse/HBASE-21320) | *Major* | **[canary] Cleanup of usage and add commentary**
+
+Cleans up usage and docs around Canary. Does not change command-line args (though we should -- smile).
+
+
+---
+
+* [HBASE-21278](https://issues.apache.org/jira/browse/HBASE-21278) | *Critical* | **Do not rollback successful sub procedures when rolling back a procedure**
+
+For the sub procedures which are successfully finished, do not do rollback. This is a change in rollback behavior.
+
+State changes which are done by sub procedures should be handled by parent procedures when rolling back. For example, when rolling back a MergeTableProcedure, we will schedule new procedures to bring the offline regions online instead of rolling back the original procedures which off-lined the regions (in fact these procedures can not be rolled back...).
+
+
+---
+
+* [HBASE-21158](https://issues.apache.org/jira/browse/HBASE-21158) | *Critical* | **Empty qualifier cell should not be returned if it does not match QualifierFilter**
+
+<!-- markdown -->
+
+Scans that make use of `QualifierFilter` previously would erroneously return both columns with an empty qualifier along with those that matched. After this change that behavior has changed to only return those columns that match.
+
+
+---
+
+* [HBASE-21098](https://issues.apache.org/jira/browse/HBASE-21098) | *Major* | **Improve Snapshot Performance with Temporary Snapshot Directory when rootDir on S3**
+
+It is recommended to place the working directory on-cluster on HDFS as doing so has shown a strong performance increase due to data locality. It is important to note that the working directory should not overlap with any existing directories as the working directory will be cleaned out during the snapshot process. Beyond that, any well-named directory on HDFS should be sufficient.
+
+
+---
+
+* [HBASE-21185](https://issues.apache.org/jira/browse/HBASE-21185) | *Minor* | **WALPrettyPrinter: Additional useful info to be printed by wal printer tool, for debugability purposes**
+
+This adds two extra features to WALPrettyPrinter tool:
+
+1) Output for each cell combined size of cell descriptors, plus the cell value itself, in a given WAL edit. This is printed on the results as "cell total size sum:" info by default;
+
+2) An optional -g/--goto argument, that allows to seek straight to that specific WAL file position, then sequentially reading the WAL from that point towards its end;
+
+
+---
+
+* [HBASE-21287](https://issues.apache.org/jira/browse/HBASE-21287) | *Major* | **JVMClusterUtil Master initialization wait time not configurable**
+
+Local HBase cluster (as used by unit tests) wait times on startup and initialization can be configured via \`hbase.master.start.timeout.localHBaseCluster\` and \`hbase.master.init.timeout.localHBaseCluster\`
+
+
+---
+
+* [HBASE-21280](https://issues.apache.org/jira/browse/HBASE-21280) | *Trivial* | **Add anchors for each heading in UI**
+
+Adds anchors #tables, #tasks, etc.
+
+
+---
+
+* [HBASE-21232](https://issues.apache.org/jira/browse/HBASE-21232) | *Major* | **Show table state in Tables view on Master home page**
+
+Add table state column to the tables panel
+
+
+---
+
+* [HBASE-21223](https://issues.apache.org/jira/browse/HBASE-21223) | *Critical* | **[amv2] Remove abort\_procedure from shell**
+
+Removed the abort\_procedure command from shell -- dangerous -- and deprecated abortProcedure in Admin API.
+
+
+---
+
+* [HBASE-20636](https://issues.apache.org/jira/browse/HBASE-20636) | *Major* | **Introduce two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED**
+
+Add two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED
+1. ROWPREFIX\_FIXED\_LENGTH: specify the length of the prefix
+2. ROWPREFIX\_DELIMITED: specify the delimiter of the prefix
+Need to specify parameters for these two types of bloomfilter, otherwise the table will fail to create
+Example:
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_FIXED\_LENGTH', CONFIGURATION =\> {'RowPrefixBloomFilter.prefix\_length' =\> '10'}}
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_DELIMITED', CONFIGURATION =\> {'RowPrefixDelimitedBloomFilter.delimiter' =\> '#'}}
+
+
+---
+
+* [HBASE-21156](https://issues.apache.org/jira/browse/HBASE-21156) | *Critical* | **[hbck2] Queue an assign of hbase:meta and bulk assign/unassign**
+
+Adds 'raw' assigns/unassigns to the Hbck Service. Takes a list of encoded region names and bulk assigns/unassigns. Skirts Master 'state' check and does not invoke Coprocessors. For repair only.
+
+Here is what HBCK2 usage looks like now:
+
+{code}
+$ java -cp hbase-hbck2-1.0.0-SNAPSHOT.jar org.apache.hbase.HBCK2
+usage: HBCK2 \<OPTIONS\> COMMAND [\<ARGS\>]
+
+Options:
+ -d,--debug run with debug output
+ -h,--help output this help message
+ --hbase.zookeeper.peerport peerport of target hbase ensemble
+ --hbase.zookeeper.quorum ensemble of target hbase
+ --zookeeper.znode.parent parent znode of target hbase
+
+Commands:
+ setTableState \<TABLENAME\> \<STATE\>
+ Possible table states: ENABLED, DISABLED, DISABLING, ENABLING
+ To read current table state, in the hbase shell run:
+ hbase\> get 'hbase:meta', '\<TABLENAME\>', 'table:state'
+ A value of \\x08\\x00 == ENABLED, \\x08\\x01 == DISABLED, etc.
+ An example making table name 'user' ENABLED:
+ $ HBCK2 setTableState users ENABLED
+ Returns whatever the previous table state was.
+
+ assign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' assign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ e.g. 1588230740 is hard-coded encoding for hbase:meta region and
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 assign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created AssignProcedure or -1 if none.
+
+ unassign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' unassign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 unassign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created UnassignProcedure or -1 if none.
+{code}
+
+
+---
+
+* [HBASE-21021](https://issues.apache.org/jira/browse/HBASE-21021) | *Major* | **Result returned by Append operation should be ordered**
+
+This change ensures Append operations are assembled into the expected order.
+
+
+---
+
+* [HBASE-21171](https://issues.apache.org/jira/browse/HBASE-21171) | *Major* | **[amv2] Tool to parse a directory of MasterProcWALs standalone**
+
+Make it so can run the WAL parse and load system in isolation. Here is an example:
+
+{code}$ HBASE\_OPTS=" -XX:+UnlockDiagnosticVMOptions -XX:+UnlockCommercialFeatures -XX:+FlightRecorder -XX:+DebugNonSafepoints" ./bin/hbase org.apache.hadoop.hbase.procedure2.store.wal.WALProcedureStore ~/big\_set\_of\_masterprocwals/
+{code}
+
+
+---
+
+* [HBASE-21107](https://issues.apache.org/jira/browse/HBASE-21107) | *Minor* | **add a metrics for netty direct memory**
+
+Add a new nettyDirectMemoryUsage under server's ipc metrics to show direct memory usage for netty rpc server.
+
+
+---
+
+* [HBASE-21153](https://issues.apache.org/jira/browse/HBASE-21153) | *Major* | **Shaded client jars should always build in relevant phase to avoid confusion**
+
+Client facing artifacts are now built whenever Maven is run through the "package" goal. Previously, the client facing artifacts would create placeholder jars that skipped repackaging HBase and third-party dependencies unless the "release" profile was active.
+
+Build times may be noticeably longer depending on your build hardware. For example, the Jenkins worker nodes maintained by ASF Infra take ~14% longer to do a full packaging build. An example portability-focused personal laptop took ~25% longer.
+
+
+---
+
+* [HBASE-20942](https://issues.apache.org/jira/browse/HBASE-20942) | *Major* | **Improve RpcServer TRACE logging**
+
+Allows configuration of the length of RPC messages printed to the log at TRACE level via "hbase.ipc.trace.param.size" in RpcServer.
+
+
+---
+
+* [HBASE-20649](https://issues.apache.org/jira/browse/HBASE-20649) | *Minor* | **Validate HFiles do not have PREFIX\_TREE DataBlockEncoding**
+
+<!-- markdown -->
+Users who have previously made use of prefix tree encoding can now check that their existing HFiles no longer contain data that uses it with an additional preupgrade check command.
+
+```
+hbase pre-upgrade validate-hfile
+```
+
+Please see the "HFile Content validation" section of the ref guide's coverage of the pre-upgrade validator tool for usage details.
+
+
+---
+
+* [HBASE-20941](https://issues.apache.org/jira/browse/HBASE-20941) | *Major* | **Create and implement HbckService in master**
+
+Adds an HBCK Service and a first method to force-change-in-table-state for use by an HBCK client effecting 'repair' to a malfunctioning HBase.
+
+
+---
+
+* [HBASE-21071](https://issues.apache.org/jira/browse/HBASE-21071) | *Major* | **HBaseTestingUtility::startMiniCluster() to use builder pattern**
+
+Cleanup all the cluster start override combos in HBaseTestingUtility by adding a StartMiniClusterOption and Builder.
+
+
+---
+
+* [HBASE-21072](https://issues.apache.org/jira/browse/HBASE-21072) | *Major* | **Block out HBCK1 in hbase2**
+
+Fence out hbase-1.x hbck1 instances. Stop them making state changes on an hbase-2.x cluster; they could do damage. We do this by writing the hbck1 lock file into place on hbase-2.x Master start-up.
+
+To disable this new behavior, set hbase.write.hbck1.lock.file to false
+
+
+---
+
+* [HBASE-20881](https://issues.apache.org/jira/browse/HBASE-20881) | *Major* | **Introduce a region transition procedure to handle all the state transition for a region**
+
+Introduced a new TransitRegionStateProcedure to replace the old AssignProcedure/UnassignProcedure/MoveRegionProcedure. In the old code, MRP will not be attached to RegionStateNode, so it can not be interrupted by ServerCrashProcedure, which introduces lots of tricky code to deal with races, and also causes lots of other difficulties on how to prevent scheduling redundant or even conflict procedures for a region.
+
+And now TRSP is the only one procedure which can bring region online or offline. When you want to schedule one, you need to check whether there is already one attached to the RegionStateNode, under the lock of the RegionStateNode. If not just go ahead, and if there is one, then you should do something, for example, give up and fail directly, or tell the TRSP to give up(This is what SCP does). Since the check and attach are both under the lock of RSN, it will greatly reduce the possible r [...]
+
+
+---
+
+* [HBASE-21012](https://issues.apache.org/jira/browse/HBASE-21012) | *Critical* | **Revert the change of serializing TimeRangeTracker**
+
+HFiles generated by 2.0.0, 2.0.1, 2.1.0 are not forward compatible to 1.4.6-, 1.3.2.1-, 1.2.6.1-, and other inactive releases. Why HFile lose compatability is hbase in new versions (2.0.0, 2.0.1, 2.1.0) use protobuf to serialize/deserialize TimeRangeTracker (TRT) while old versions use DataInput/DataOutput. To solve this, We have to put HBASE-21012 to 2.x and put HBASE-21013 in 1.x. For more information, please check HBASE-21008.
+
+
+---
+
+* [HBASE-20965](https://issues.apache.org/jira/browse/HBASE-20965) | *Major* | **Separate region server report requests to new handlers**
+
+After HBASE-20965, we can use MasterFifoRpcScheduler in master to separate RegionServerReport requests to indenpedent handler. To use this feature, please set "hbase.master.rpc.scheduler.factory.class" to
+ "org.apache.hadoop.hbase.ipc.MasterFifoRpcScheduler". Use "hbase.master.server.report.handler.count" to set RegionServerReport handlers count, the default value is half of "hbase.regionserver.handler.count" value, but at least 1, and the other handlers count in master is "hbase.regionserver.handler.count" value minus RegionServerReport handlers count, but at least 1 too.
+
+
+---
+
+* [HBASE-20813](https://issues.apache.org/jira/browse/HBASE-20813) | *Minor* | **Remove RPC quotas when the associated table/Namespace is dropped off**
+
+In previous releases, when a Space Quota was configured on a table or namespace and that table or namespace was deleted, the Space Quota was also deleted. This change improves the implementation so that the same is also done for RPC Quotas.
+
+
+---
+
+* [HBASE-20986](https://issues.apache.org/jira/browse/HBASE-20986) | *Major* | **Separate the config of block size when we do log splitting and write Hlog**
+
+After HBASE-20986, we can set different value to block size of WAL and recovered edits. Both of their default value is 2 \* default HDFS blocksize. And hbase.regionserver.recoverededits.blocksize is for block size of recovered edits while hbase.regionserver.hlog.blocksize is for block size of WAL.
+
+
+---
+
+* [HBASE-20856](https://issues.apache.org/jira/browse/HBASE-20856) | *Minor* | **PITA having to set WAL provider in two places**
+
+With this change if a WAL's meta provider (hbase.wal.meta\_provider) is not explicitly set, it now defaults to whatever hbase.wal.provider is set to. Previous, the two settings operated independently, each with its own default.
+
+This change is operationally incompatible with previous HBase versions because the default WAL meta provider no longer defaults to AsyncFSWALProvider but to hbase.wal.provider.
+
+The thought is that this is more in line with an operator's expectation, that a change in hbase.wal.provider is sufficient to change how WALs are written, especially given hbase.wal.meta\_provider is an obscure configuration and that the very idea that meta regions would have their own wal provider would likely come as a surprise.
+
+
+---
+
+* [HBASE-20538](https://issues.apache.org/jira/browse/HBASE-20538) | *Critical* | **Upgrade our hadoop versions to 2.7.7 and 3.0.3**
+
+Update hadoop-two.version to 2.7.7 and hadoop-three.version to 3.0.3 due to a JDK issue which is solved by HADOOP-15473.
+
+
+---
+
+* [HBASE-20846](https://issues.apache.org/jira/browse/HBASE-20846) | *Major* | **Restore procedure locks when master restarts**
+
+1. Make hasLock method final, and add a locked field in Procedure to record whether we have the lock. We will set it to true in doAcquireLock and to false in doReleaseLock. The sub procedures do not need to manage it any more.
+
+2. Also added a locked field in the proto message. When storing, the field will be set according to the return value of hasLock. And when loading, there is a new field in Procedure called lockedWhenLoading. We will set it to true if the locked field in proto message is true.
+
+3. The reason why we can not set the locked field directly to true by calling doAcquireLock is that, during initialization, most procedures need to wait until master is initialized. So the solution here is that, we introduced a new method called waitInitialized in Procedure, and move the wait master initialized related code from acquireLock to this method. And we added a restoreLock method to Procedure, if lockedWhenLoading is true, we will call the acquireLock to get the lock, but do no [...]
+
+
+---
+
+* [HBASE-20672](https://issues.apache.org/jira/browse/HBASE-20672) | *Minor* | **New metrics ReadRequestRate and WriteRequestRate**
+
+Exposing 2 new metrics in HBase to provide ReadRequestRate and WriteRequestRate at region server level. These metrics give the rate of request handled by the region server and are reset after every monitoring interval.
+
+
+---
+
+* [HBASE-6028](https://issues.apache.org/jira/browse/HBASE-6028) | *Minor* | **Implement a cancel for in-progress compactions**
+
+Added a new command to the shell to switch on/off compactions called "compaction\_switch". Disabling compactions will interrupt any currently ongoing compactions. This setting will be lost on restart of the server. Added the configuration hbase.regionserver.compaction.enabled so user can enable/disable compactions via hbase-site.xml.
+
+
+---
+
+* [HBASE-20884](https://issues.apache.org/jira/browse/HBASE-20884) | *Major* | **Replace usage of our Base64 implementation with java.util.Base64**
+
+Class org.apache.hadoop.hbase.util.Base64 has been removed in it's entirety from HBase 2+. In HBase 1, unused methods have been removed from the class and the audience was changed from Public to Private. This class was originally intended as an internal utility class that could be used externally but thinking since changed; these classes should not have been advertised as public to end-users.
+
+This represents an incompatible change for users who relied on this implementation. An alternative implementation for affected clients is available at java.util.Base64 when using Java 8 or newer; be aware, it may encode/decode differently. For clients seeking to restore this specific implementation, it is available in the public domain for download at http://iharder.sourceforge.net/current/java/base64/
+
+
+---
+
+* [HBASE-20357](https://issues.apache.org/jira/browse/HBASE-20357) | *Major* | **AccessControlClient API Enhancement**
+
+This enhances the AccessControlClient APIs to retrieve the permissions based on namespace, table name, family and qualifier for specific user. AccessControlClient can also validate a user whether allowed to perform specified operations on a particular table.
+Following APIs have been added,
+1) getUserPermissions(Connection connection, String tableRegex, byte[] columnFamily, byte[] columnQualifier, String userName)
+ Scope of retrieving permission will be same as existing.
+2) hasPermission(onnection connection, String tableName, byte[] columnFamily, byte[] columnQualifier, String userName, Permission.Action... actions)
+ Scope of validating user privilege,
+ User can perform self check without any special privilege but ADMIN privilege will be required to perform check for other users.
+ For example, suppose there are two users "userA" & "userB" then there can be below scenarios,
+ a. When userA want to check whether userA have privilege to perform mentioned actions
+ userA don't need ADMIN privilege, as it's a self query.
+ b. When userA want to check whether userB have privilege to perform mentioned actions,
+ userA must have ADMIN or superuser privilege, as it's trying to query for other user.
+
+
+
+
+The HBase `shell` now includes a command to list regions currently in transition.
+
+```
+HBase Shell
+Use "help" to get list of supported commands.
+Use "exit" to quit this interactive shell.
+Version 1.5.0-SNAPSHOT, r9bb6d2fa8b760f16cd046657240ebd4ad91cb6de, Mon Oct 8 21:05:50 UTC 2018
+
+hbase(main):001:0> help 'rit'
+List all regions in transition.
+Examples:
+ hbase> rit
+
+hbase(main):002:0> create ...
+0 row(s) in 2.5150 seconds
+=> Hbase::Table - IntegrationTestBigLinkedList
+
+hbase(main):003:0> rit
+0 row(s) in 0.0340 seconds
+
+hbase(main):004:0> unassign '56f0c38c81ae453d19906ce156a2d6a1'
+0 row(s) in 0.0540 seconds
+
+hbase(main):005:0> rit
+IntegrationTestBigLinkedList,L\xCC\xCC\xCC\xCC\xCC\xCC\xCB,1539117183224.56f0c38c81ae453d19906ce156a2d6a1. state=PENDING_CLOSE, ts=Tue Oct 09 20:33:34 UTC 2018 (0s ago), server=null
+1 row(s) in 0.0170 seconds
+```
+
+
+---
+
+* [HBASE-21567](https://issues.apache.org/jira/browse/HBASE-21567) | *Major* | **Allow overriding configs starting up the shell**
+
+Allow passing of -Dkey=value option to shell to override hbase-\* configuration: e.g.:
+
+$ ./bin/hbase shell -Dhbase.zookeeper.quorum=ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org -Draining=false
+...
+hbase(main):001:0\> @shell.hbase.configuration.get("hbase.zookeeper.quorum")
+=\> "ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org"
+hbase(main):002:0\> @shell.hbase.configuration.get("raining")
+=\> "false"
+
+
+---
+
+* [HBASE-21560](https://issues.apache.org/jira/browse/HBASE-21560) | *Major* | **Return a new TableDescriptor for MasterObserver#preModifyTable to allow coprocessor modify the TableDescriptor**
+
+Incompatible change. Allow MasterObserver#preModifyTable to return a new TableDescriptor. And master will use this returned TableDescriptor to modify table.
+
+
+---
+
+* [HBASE-21551](https://issues.apache.org/jira/browse/HBASE-21551) | *Blocker* | **Memory leak when use scan with STREAM at server side**
+
+<!-- markdown -->
+# HBASE 2.2.0 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [HBASE-21991](https://issues.apache.org/jira/browse/HBASE-21991) | *Major* | **Fix MetaMetrics issues - [Race condition, Faulty remove logic], few improvements**
+
+Moving IA.Public class LossyCounting to IA.Private.
+
+
+---
+
+* [HBASE-20970](https://issues.apache.org/jira/browse/HBASE-20970) | *Major* | **Update hadoop check versions for hadoop3 in hbase-personality**
+
+Add hadoop 3.0.3, 3.1.1 3.1.2 in our hadoop check jobs.
+
+
+---
+
+* [HBASE-21784](https://issues.apache.org/jira/browse/HBASE-21784) | *Major* | **Dump replication queue should show list of wal files ordered chronologically**
+
+The DumpReplicationQueues tool will now list replication queues sorted in chronological order.
+
+
+---
+
+* [HBASE-22384](https://issues.apache.org/jira/browse/HBASE-22384) | *Minor* | **Formatting issues in administration section of book**
+
+Fixes a formatting issue in the administration section of the book, where listing indentation were a little bit off.
+
+
+---
+
+* [HBASE-22399](https://issues.apache.org/jira/browse/HBASE-22399) | *Major* | **Change default hadoop-two.version to 2.8.x and remove the 2.7.x hadoop checks**
+
+Now the default hadoop-two.version has been changed to 2.8.5, and all hadoop versions before 2.8.2(exclude) will not be supported any more.
+
+
+---
+
+* [HBASE-22392](https://issues.apache.org/jira/browse/HBASE-22392) | *Trivial* | **Remove extra/useless +**
+
+Removed extra + in HRegion, HStore and LoadIncrementalHFiles for branch-2 and HRegion and HStore for branch-1.
+
+
+---
+
+* [HBASE-21536](https://issues.apache.org/jira/browse/HBASE-21536) | *Trivial* | **Fix completebulkload usage instructions**
+
+Added completebulkload short name for BulkLoadHFilesTool to bin/hbase.
+
+
+---
+
+* [HBASE-20494](https://issues.apache.org/jira/browse/HBASE-20494) | *Major* | **Upgrade com.yammer.metrics dependency**
+
+Updated metrics core from 3.2.1 to 3.2.6.
+
+
+---
+
+* [HBASE-22358](https://issues.apache.org/jira/browse/HBASE-22358) | *Minor* | **Change rubocop configuration for method length**
+
+The rubocop definition for the maximum method length was set to 75.
+
+
+---
+
+* [HBASE-22379](https://issues.apache.org/jira/browse/HBASE-22379) | *Minor* | **Fix Markdown for "Voting on Release Candidates" in book**
+
+Fixes the formatting of the "Voting on Release Candidates" to actually show the quote and code formatting of the RAT check.
+
+
+---
+
+* [HBASE-20851](https://issues.apache.org/jira/browse/HBASE-20851) | *Minor* | **Change rubocop config for max line length of 100**
+
+The rubocop configuration in the hbase-shell module now allows a line length with 100 characters, instead of 80 as before. For everything before 2.1.5 this change introduces rubocop itself.
+
+
+---
+
+* [HBASE-22054](https://issues.apache.org/jira/browse/HBASE-22054) | *Minor* | **Space Quota: Compaction is not working for super user in case of NO\_WRITES\_COMPACTIONS**
+
+This change allows the system and superusers to initiate compactions, even when a space quota violation policy disallows compactions from happening. The original intent behind disallowing of compactions was to prevent end-user compactions from creating undue I/O load, not disallowing \*any\* compaction in the system.
+
+
+---
+
+* [HBASE-22292](https://issues.apache.org/jira/browse/HBASE-22292) | *Blocker* | **PreemptiveFastFailInterceptor clean repeatedFailuresMap issue**
+
+Adds new configuration hbase.client.failure.map.cleanup.interval which defaults to ten minutes.
+
+
+---
+
+* [HBASE-22155](https://issues.apache.org/jira/browse/HBASE-22155) | *Major* | **Move 2.2.0 on to hbase-thirdparty-2.2.0**
+
+ Updates libs used internally by hbase via hbase-thirdparty as follows:
+
+ gson 2.8.1 -\\\> 2.8.5
+ guava 22.0 -\\\> 27.1-jre
+ pb 3.5.1 -\\\> 3.7.0
+ netty 4.1.17 -\\\> 4.1.34
+ commons-collections4 4.1 -\\\> 4.3
+
+
+---
+
+* [HBASE-22178](https://issues.apache.org/jira/browse/HBASE-22178) | *Major* | **Introduce a createTableAsync with TableDescriptor method in Admin**
+
+Introduced
+
+Future\<Void\> createTableAsync(TableDescriptor);
+
+
+---
+
+* [HBASE-22108](https://issues.apache.org/jira/browse/HBASE-22108) | *Major* | **Avoid passing null in Admin methods**
+
+Introduced these methods:
+void move(byte[]);
+void move(byte[], ServerName);
+Future\<Void\> splitRegionAsync(byte[]);
+
+These methods are deprecated:
+void move(byte[], byte[])
+
+
+---
+
+* [HBASE-22152](https://issues.apache.org/jira/browse/HBASE-22152) | *Major* | **Create a jenkins file for yetus to processing GitHub PR**
+
+Add a new jenkins file for running pre commit check for GitHub PR.
+
+
+---
+
+* [HBASE-22007](https://issues.apache.org/jira/browse/HBASE-22007) | *Major* | **Add restoreSnapshot and cloneSnapshot with acl methods in AsyncAdmin**
+
+Add cloneSnapshot/restoreSnapshot with acl methods in AsyncAdmin.
+
+
+---
+
+* [HBASE-22123](https://issues.apache.org/jira/browse/HBASE-22123) | *Minor* | **REST gateway reports Insufficient permissions exceptions as 404 Not Found**
+
+When insufficient permissions, you now get:
+
+HTTP/1.1 403 Forbidden
+
+on the HTTP side, and in the message
+
+Forbidden
+org.apache.hadoop.hbase.security.AccessDeniedException: org.apache.hadoop.hbase.security.AccessDeniedException: Insufficient permissions for user ‘myuser',action: get, tableName:mytable, family:cf.
+at org.apache.ranger.authorization.hbase.RangerAuthorizationCoprocessor.authorizeAccess(RangerAuthorizationCoprocessor.java:547)
+and the rest of the ADE stack
+
+
+---
+
+* [HBASE-22100](https://issues.apache.org/jira/browse/HBASE-22100) | *Minor* | **False positive for error prone warnings in pre commit job**
+
+Now we will sort the javac WARNING/ERROR before generating diff in pre-commit so we can get a stable output for the error prone. The downside is that we just sort the output lexicographically so the line number will also be sorted lexicographically, which is a bit strange to human.
+
+
+---
+
+* [HBASE-22057](https://issues.apache.org/jira/browse/HBASE-22057) | *Major* | **Impose upper-bound on size of ZK ops sent in a single multi()**
+
+Exposes a new configuration property "zookeeper.multi.max.size" which dictates the maximum size of deletes that HBase will make to ZooKeeper in a single RPC. This property defaults to 1MB, which should fall beneath the default ZooKeeper limit of 2MB, controlled by "jute.maxbuffer".
+
+
+---
+
+* [HBASE-22052](https://issues.apache.org/jira/browse/HBASE-22052) | *Major* | **pom cleaning; filter out jersey-core in hadoop2 to match hadoop3 and remove redunant version specifications**
+
+<!-- markdown -->
+Fixed awkward dependency issue that prevented site building.
+
+#### note specific to HBase 2.1.4
+HBase 2.1.4 shipped with an early version of this fix that incorrectly altered the libraries included in our binary assembly for using Apache Hadoop 2.7 (the current build default Hadoop version for 2.1.z). For folks running out of the box against a Hadoop 2.7 cluster (or folks who skip the installation step of [replacing the bundled Hadoop libraries](http://hbase.apache.org/book.html#hadoop)) this will result in a failure at Region Server startup due to a missing class definition. e.g.:
+```
+2019-03-27 09:02:05,779 ERROR [main] regionserver.HRegionServer: Failed construction RegionServer
+java.lang.NoClassDefFoundError: org/apache/htrace/SamplerBuilder
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:644)
+ at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:628)
+ at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
+ at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)
+ at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:93)
+ at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2701)
+ at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2683)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:372)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:171)
+ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:356)
+ at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getRootDir(CommonFSUtils.java:362)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.isValidWALRootDir(CommonFSUtils.java:411)
+ at org.apache.hadoop.hbase.util.CommonFSUtils.getWALRootDir(CommonFSUtils.java:387)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.initializeFileSystem(HRegionServer.java:704)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.<init>(HRegionServer.java:613)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
+ at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
+ at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
+ at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.constructRegionServer(HRegionServer.java:3029)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.start(HRegionServerCommandLine.java:63)
+ at org.apache.hadoop.hbase.regionserver.HRegionServerCommandLine.run(HRegionServerCommandLine.java:87)
+ at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
+ at org.apache.hadoop.hbase.util.ServerCommandLine.doMain(ServerCommandLine.java:149)
+ at org.apache.hadoop.hbase.regionserver.HRegionServer.main(HRegionServer.java:3047)
+Caused by: java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
+ at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
+ at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
+ at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
+ ... 26 more
+
+```
+
+Workaround via any _one_ of the following:
+* If you are running against a Hadoop cluster that is 2.8+, ensure you replace the Hadoop libaries in the default binary assembly with those for your version.
+* If you are running against a Hadoop cluster that is 2.8+, build the binary assembly from the source release while specifying your Hadoop version.
+* If you are running against a Hadoop cluster that is a supported 2.7 release, ensure the `hadoop` executable is in the `PATH` seen at Region Server startup and that you are not using the `HBASE_DISABLE_HADOOP_CLASSPATH_LOOKUP` bypass.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers via the HBASE_CLASSPATH environment variable.
+* For any supported Hadoop version, manually make the Apache HTrace artifact `htrace-core-3.1.0-incubating.jar` available to all Region Servers by copying it into the directory `${HBASE_HOME}/lib/client-facing-thirdparty/`.
+
+
+---
+
+* [HBASE-22065](https://issues.apache.org/jira/browse/HBASE-22065) | *Major* | **Add listTableDescriptors(List\<TableName\>) method in AsyncAdmin**
+
+Add a listTableDescriptors(List\<TableName\>) method in the AsyncAdmin interface, to align with the Admin interface.
+
+
+---
+
+* [HBASE-22040](https://issues.apache.org/jira/browse/HBASE-22040) | *Major* | **Add mergeRegionsAsync with a List of region names method in AsyncAdmin**
+
+Add a mergeRegionsAsync(byte[][], boolean) method in the AsyncAdmin interface.
+
+Instead of using assert, now we will throw IllegalArgumentException when you want to merge less than 2 regions at client side. And also, at master side, instead of using assert, now we will throw DoNotRetryIOException if you want merge more than 2 regions, since we only support merging two regions at once for now.
+
+
+---
+
+* [HBASE-22039](https://issues.apache.org/jira/browse/HBASE-22039) | *Major* | **Should add the synchronous parameter for the XXXSwitch method in AsyncAdmin**
+
+Add drainXXX parameter for balancerSwitch/splitSwitch/mergeSwitch methods in the AsyncAdmin interface, which has the same meaning with the synchronous parameter for these methods in the Admin interface.
+
+
+---
+
+* [HBASE-21810](https://issues.apache.org/jira/browse/HBASE-21810) | *Major* | **bulkload support set hfile compression on client**
+
+bulkload (HFileOutputFormat2) support config the compression on client ,you can set the job configuration "hbase.mapreduce.hfileoutputformat.compression" override the auto-detection of the target table's compression
+
+
+---
+
+* [HBASE-22000](https://issues.apache.org/jira/browse/HBASE-22000) | *Major* | **Deprecated isTableAvailable with splitKeys**
+
+Deprecated AsyncTable.isTableAvailable(TableName, byte[][]).
+
+
+---
+
+* [HBASE-21871](https://issues.apache.org/jira/browse/HBASE-21871) | *Major* | **Support to specify a peer table name in VerifyReplication tool**
+
+After HBASE-21871, we can specify a peer table name with --peerTableName in VerifyReplication tool like the following:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable 5 TestTable
+
+In addition, we can compare any 2 tables in any remote clusters with specifying both peerId and --peerTableName.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication --peerTableName=peerTable zk1,zk2,zk3:2181/hbase TestTable
+
+
+---
+
+* [HBASE-15728](https://issues.apache.org/jira/browse/HBASE-15728) | *Major* | **Add remaining per-table region / store / flush / compaction related metrics**
+
+Adds below flush, split, and compaction metrics
+
+ + // split related metrics
+ + private MutableFastCounter splitRequest;
+ + private MutableFastCounter splitSuccess;
+ + private MetricHistogram splitTimeHisto;
+ +
+ + // flush related metrics
+ + private MetricHistogram flushTimeHisto;
+ + private MetricHistogram flushMemstoreSizeHisto;
+ + private MetricHistogram flushOutputSizeHisto;
+ + private MutableFastCounter flushedMemstoreBytes;
+ + private MutableFastCounter flushedOutputBytes;
+ +
+ + // compaction related metrics
+ + private MetricHistogram compactionTimeHisto;
+ + private MetricHistogram compactionInputFileCountHisto;
+ + private MetricHistogram compactionInputSizeHisto;
+ + private MetricHistogram compactionOutputFileCountHisto;
+ + private MetricHistogram compactionOutputSizeHisto;
+ + private MutableFastCounter compactedInputBytes;
+ + private MutableFastCounter compactedOutputBytes;
+ +
+ + private MetricHistogram majorCompactionTimeHisto;
+ + private MetricHistogram majorCompactionInputFileCountHisto;
+ + private MetricHistogram majorCompactionInputSizeHisto;
+ + private MetricHistogram majorCompactionOutputFileCountHisto;
+ + private MetricHistogram majorCompactionOutputSizeHisto;
+ + private MutableFastCounter majorCompactedInputBytes;
+ + private MutableFastCounter majorCompactedOutputBytes;
+
+
+---
+
+* [HBASE-20886](https://issues.apache.org/jira/browse/HBASE-20886) | *Critical* | **[Auth] Support keytab login in hbase client**
+
+From 2.2.0, hbase supports client login via keytab. To use this feature, client should specify \`hbase.client.keytab.file\` and \`hbase.client.keytab.principal\` in hbase-site.xml, then the connection will contain the needed credentials which be renewed periodically to communicate with kerberized hbase cluster.
+
+
+---
+
+* [HBASE-21410](https://issues.apache.org/jira/browse/HBASE-21410) | *Major* | **A helper page that help find all problematic regions and procedures**
+
+After HBASE-21410, we add a helper page to Master UI. This helper page is mainly to help HBase operator quickly found all regions and pids that are get stuck.
+There are 2 entries to get in this page.
+One is showing in the Regions in Transition section, it made "num region(s) in transition" a link that you can click and check all regions in transition and their related procedure IDs.
+The other one is showing in the table details section, it made the number of CLOSING or OPENING regions a link, which you can click and check regions and related procedure IDs of CLOSING or OPENING regions of a certain table.
+In this helper page, not only you can see all regions and related procedures, there are 2 buttons at the top which will show these regions or procedure IDs in text format. This is mainly aim to help operator to easily copy and paste all problematic procedure IDs and encoded region names to HBCK2's command line, by which we HBase operator can bypass these procedures or assign these regions.
+
+
+---
+
+* [HBASE-21588](https://issues.apache.org/jira/browse/HBASE-21588) | *Major* | **Procedure v2 wal splitting implementation**
+
+After HBASE-21588, we introduce a new way to do WAL splitting coordination by procedure framework. This can simplify the process of WAL splitting and no need to connect zookeeper any more.
+During ServerCrashProcedure, it will create a SplitWALProcedure for each WAL that need to split. Then each SplitWALProcedure will spawn a SplitWALRemoteProcedure to send the request to regionserver.
+At the RegionServer side, whole process is handled by SplitWALCallable. It split the WAL and return the result to master.
+According to my test, this patch has a better performance as the number of WALs that need to split increase. And it can relieve the pressure on zookeeper.
+
+
+---
+
+* [HBASE-20734](https://issues.apache.org/jira/browse/HBASE-20734) | *Major* | **Colocate recovered edits directory with hbase.wal.dir**
+
+Previously the recovered.edits directory was under the root directory. This JIRA moves the recovered.edits directory to be under the hbase.wal.dir if set. It also adds a check for any recovered.edits found under the root directory for backwards compatibility. This gives improvements when a faster media(like SSD) or more local FileSystem is used for the hbase.wal.dir than the root dir.
+
+
+---
+
+* [HBASE-20401](https://issues.apache.org/jira/browse/HBASE-20401) | *Minor* | **Make \`MAX\_WAIT\` and \`waitIfNotFinished\` in CleanerContext configurable**
+
+When oldwals (and hfile) cleaner cleans stale wals (and hfiles), it will periodically check and wait the clean results from filesystem, the total wait time will be no more than a max time.
+
+The periodically wait and check configurations are hbase.oldwals.cleaner.thread.check.interval.msec (default is 500 ms) and hbase.regionserver.hfilecleaner.thread.check.interval.msec (default is 1000 ms).
+
+Meanwhile, The max time configurations are hbase.oldwals.cleaner.thread.timeout.msec and hbase.regionserver.hfilecleaner.thread.timeout.msec, they are set to 60 seconds by default.
+
+All support dynamic configuration.
+
+e.g. in the oldwals cleaning scenario, one may consider tuning hbase.oldwals.cleaner.thread.timeout.msec and hbase.oldwals.cleaner.thread.check.interval.msec
+
+1. While deleting a oldwal never complete (strange but possible), then delete file task needs to wait for a max of 60 seconds. Here, 60 seconds might be too long, or the opposite way is to increase more than 60 seconds in the use cases of slow file delete.
+2. The check and wait of a file delete is set to default in the period of 500 milliseconds, one might want to tune this checking period to a short interval to check more frequently or to a longer interval to avoid checking too often to manage their delete file task checking period (the longer interval may be use to avoid checking too fast while using a high latency storage).
+
+
+---
+
+* [HBASE-21481](https://issues.apache.org/jira/browse/HBASE-21481) | *Major* | **[acl] Superuser's permissions should not be granted or revoked by any non-su global admin**
+
+HBASE-21481 improves the quality of access control, by strengthening the protection of super users's privileges.
+
+
+---
+
+* [HBASE-21082](https://issues.apache.org/jira/browse/HBASE-21082) | *Critical* | **Reimplement assign/unassign related procedure metrics**
+
+Now we have four types of RIT procedure metrics, assign, unassign, move, reopen. The meaning of assign/unassign is changed, as we will not increase the unassign metric and then the assign metric when moving a region.
+Also introduced two new procedure metrics, open and close, which are used to track the open/close region calls to region server. We may send open/close multiple times to finish a RIT since we may retry multiple times.
+
+
+---
+
+* [HBASE-20724](https://issues.apache.org/jira/browse/HBASE-20724) | *Critical* | **Sometimes some compacted storefiles are still opened after region failover**
+
+Problem: This is an old problem since HBASE-2231. The compaction event marker was only writed to WAL. But after flush, the WAL may be archived, which means an useful compaction event marker be deleted, too. So the compacted store files cannot be archived when region open and replay WAL.
+
+Solution: After this jira, the compaction event tracker will be writed to HFile. When region open and load store files, read the compaction evnet tracker from HFile and archive the compacted store files which still exist.
+
+
+---
+
+* [HBASE-21820](https://issues.apache.org/jira/browse/HBASE-21820) | *Major* | **Implement CLUSTER quota scope**
+
+HBase contains two quota scopes: MACHINE and CLUSTER. Before this patch, set quota operations did not expose scope option to client api and use MACHINE as default, CLUSTER scope can not be set and used.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+
+This issue implements CLUSTER scope in a simple way: For user, namespace, user over namespace quota, use [ClusterLimit / RSNum] as machine limit. For table and user over table quota, use [ClusterLimit / TotalTableRegionNum \* MachineTableRegionNum] as machine limit.
+After this patch, user can set CLUSTER scope quota, but MACHINE is still default if user ignore scope.
+Shell commands are as follows:
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec'
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> MACHINE
+set\_quota, TYPE =\> THROTTLE, TABLE =\> 't1', LIMIT =\> '10req/sec', SCOPE =\> CLUSTER
+
+
+---
+
+* [HBASE-21057](https://issues.apache.org/jira/browse/HBASE-21057) | *Minor* | **upgrade to latest spotbugs**
+
+Change spotbugs version to 3.1.11.
+
+
+---
+
+* [HBASE-21922](https://issues.apache.org/jira/browse/HBASE-21922) | *Major* | **BloomContext#sanityCheck may failed when use ROWPREFIX\_DELIMITED bloom filter**
+
+Remove bloom filter type ROWPREFIX\_DELIMITED. May add it back when find a better solution.
+
+
+---
+
+* [HBASE-21783](https://issues.apache.org/jira/browse/HBASE-21783) | *Major* | **Support exceed user/table/ns throttle quota if region server has available quota**
+
+Support enable or disable exceed throttle quota. Exceed throttle quota means, user can over consume user/namespace/table quota if region server has additional available quota because other users don't consume at the same time.
+Use the following shell commands to enable/disable exceed throttle quota: enable\_exceed\_throttle\_quota
+disable\_exceed\_throttle\_quota
+There are two limits when enable exceed throttle quota:
+1. Must set at least one read and one write region server throttle quota;
+2. All region server throttle quotas must be in seconds time unit. Because once previous requests exceed their quota and consume region server quota, quota in other time units may be refilled in a long time, this may affect later requests.
+
+
+---
+
+* [HBASE-20587](https://issues.apache.org/jira/browse/HBASE-20587) | *Major* | **Replace Jackson with shaded thirdparty gson**
+
+Remove jackson dependencies from most hbase modules except hbase-rest, use shaded gson instead. The output json will be a bit different since jackson can use getter/setter, but gson will always use the fields.
+
+
+---
+
+* [HBASE-21928](https://issues.apache.org/jira/browse/HBASE-21928) | *Major* | **Deprecated HConstants.META\_QOS**
+
+Mark HConstants.META\_QOS as deprecated. It is for internal use only, which is the highest priority. You should not try to set a priority greater than or equal to this value, although it is no harm but also useless.
+
+
+---
+
+* [HBASE-17942](https://issues.apache.org/jira/browse/HBASE-17942) | *Major* | **Disable region splits and merges per table**
+
+This patch adds the ability to disable split and/or merge for a table (By default, split and merge are enabled for a table).
+
+
+---
+
+* [HBASE-21636](https://issues.apache.org/jira/browse/HBASE-21636) | *Major* | **Enhance the shell scan command to support missing scanner specifications like ReadType, IsolationLevel etc.**
+
+Allows shell to set Scan options previously not exposed. See additions as part of the scan help by typing following hbase shell:
+
+hbase\> help 'scan'
+
+
+---
+
+* [HBASE-21201](https://issues.apache.org/jira/browse/HBASE-21201) | *Major* | **Support to run VerifyReplication MR tool without peerid**
+
+We can specify peerQuorumAddress instead of peerId in VerifyReplication tool. So it no longer requires peerId to be setup when using this tool.
+
+For example:
+hbase org.apache.hadoop.hbase.mapreduce.replication.VerifyReplication zk1,zk2,zk3:2181/hbase testTable
+
+
+---
+
+* [HBASE-21838](https://issues.apache.org/jira/browse/HBASE-21838) | *Major* | **Create a special ReplicationEndpoint just for verifying the WAL entries are fine**
+
+Introduce a VerifyWALEntriesReplicationEndpoint which replicates nothing but only verifies if all the cells are valid.
+It can be used to capture bugs for writing WAL, as most times we will not read the WALs again after writing it if there are no region server crashes.
+
+
+---
+
+* [HBASE-21727](https://issues.apache.org/jira/browse/HBASE-21727) | *Minor* | **Simplify documentation around client timeout**
+
+Deprecated HBaseConfiguration#getInt(Configuration, String, String, int) method and removed it from 3.0.0 version.
+
+
+---
+
+* [HBASE-21764](https://issues.apache.org/jira/browse/HBASE-21764) | *Major* | **Size of in-memory compaction thread pool should be configurable**
+
+Introduced an new config key in this issue: hbase.regionserver.inmemory.compaction.pool.size. the default value would be 10. you can configure this to set the pool size of in-memory compaction pool. Note that all memstores in one region server will share the same pool, so if you have many regions in one region server, you need to set this larger to compact faster for better read performance.
+
+
+---
+
+* [HBASE-21684](https://issues.apache.org/jira/browse/HBASE-21684) | *Major* | **Throw DNRIOE when connection or rpc client is closed**
+
+Make StoppedRpcClientException extend DoNotRetryIOException.
+
+
+---
+
+* [HBASE-21739](https://issues.apache.org/jira/browse/HBASE-21739) | *Major* | **Move grant/revoke from regionserver to master**
+
+To implement user permission control in Precedure V2, move grant and revoke method from AccessController to master firstly.
+Mark AccessController#grant and AccessController#revoke as deprecated and please use Admin#grant and Admin#revoke instead.
+
+
+---
+
+* [HBASE-21791](https://issues.apache.org/jira/browse/HBASE-21791) | *Blocker* | **Upgrade thrift dependency to 0.12.0**
+
+IMPORTANT: Due to security issues, all users who use hbase thrift should avoid using releases which do not have this fix.
+
+The effect releases are:
+2.1.x: 2.1.2 and below
+2.0.x: 2.0.4 and below
+1.x: 1.4.x and below
+
+If you are using the effect releases above, please consider upgrading to a newer release ASAP.
+
+
+---
+
+* [HBASE-21792](https://issues.apache.org/jira/browse/HBASE-21792) | *Major* | **Mark HTableMultiplexer as deprecated and remove it in 3.0.0**
+
+HTableMultiplexer exposes the implementation class, and it is incomplete, so we mark it as deprecated and remove it in 3.0.0 release.
+
+There is no direct replacement for HTableMultiplexer, please use BufferedMutator if you want to batch mutations to a table.
+
+
+---
+
+* [HBASE-21782](https://issues.apache.org/jira/browse/HBASE-21782) | *Major* | **LoadIncrementalHFiles should not be IA.Public**
+
+Introduce a BulkLoadHFiles interface which is marked as IA.Public, for doing bulk load programmatically.
+Introduce a BulkLoadHFilesTool which extends BulkLoadHFiles, and is marked as IA.LimitedPrivate(TOOLS), for using from command line.
+The old LoadIncrementalHFiles is deprecated and will be removed in 3.0.0.
+
+
+---
+
+* [HBASE-21762](https://issues.apache.org/jira/browse/HBASE-21762) | *Major* | **Move some methods in ClusterConnection to Connection**
+
+Move the two getHbck method from ClusterConnection to Connection, and mark the methods as IA.LimitedPrivate(HBCK), as ClusterConnection is IA.Private and should not be depended by HBCK2.
+
+Add a clearRegionLocationCache method in Connection to clear the region location cache for all the tables. As in RegionLocator, most of the methods have a 'reload' parameter, which implicitly tells user that we have a region location cache, so adding a method to clear the cache is fine.
+
+
+---
+
+* [HBASE-21713](https://issues.apache.org/jira/browse/HBASE-21713) | *Major* | **Support set region server throttle quota**
+
+Support set region server rpc throttle quota which represents the read/write ability of region servers and throttles when region server's total requests exceeding the limit.
+
+Use the following shell command to set RS quota:
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', THROTTLE\_TYPE =\> WRITE, LIMIT =\> '20000req/sec'
+set\_quota TYPE =\> THROTTLE, REGIONSERVER =\> 'all', LIMIT =\> NONE
+"all" represents the throttle quota of all region servers and setting specified region server quota isn't supported currently.
+
+
+---
+
+* [HBASE-21689](https://issues.apache.org/jira/browse/HBASE-21689) | *Minor* | **Make table/namespace specific current quota info available in shell(describe\_namespace & describe)**
+
+In shell commands "describe\_namespace" and "describe", which are used to see the descriptors of the namespaces and tables respectively, quotas set on that particular namespace/table will also be printed along.
+
+
+---
+
+* [HBASE-17370](https://issues.apache.org/jira/browse/HBASE-17370) | *Major* | **Fix or provide shell scripts to drain and decommission region server**
+
+Adds shell support for the following:
+- List decommissioned/draining region servers
+- Decommission a list of region servers, optionally offload corresponding regions
+- Recommission a region server, optionally load a list of passed regions
+
+
+---
+
+* [HBASE-21734](https://issues.apache.org/jira/browse/HBASE-21734) | *Major* | **Some optimization in FilterListWithOR**
+
+After HBASE-21620, the filterListWithOR has been a bit slow because we need to merge each sub-filter's RC , while before HBASE-21620, we will skip many RC merging, but the logic was wrong. So here we choose another way to optimaze the performance: removing the KeyValueUtil#toNewKeyCell.
+Anoop Sam John suggested that the KeyValueUtil#toNewKeyCell can save some GC before because if we copy key part of cell into a single byte[], then the block the cell refering won't be refered by the filter list any more, the upper layer can GC the data block quickly. while after HBASE-21620, we will update the prevCellList for every encountered cell now, so the lifecycle of cell in prevCellList for FilterList will be quite shorter. so just use the cell ref for saving cpu.
+BTW, we removed all the arrays streams usage in filter list, because it's also quite time-consuming in our test.
+
+
+---
+
+* [HBASE-21738](https://issues.apache.org/jira/browse/HBASE-21738) | *Critical* | **Remove all the CSLM#size operation in our memstore because it's an quite time consuming.**
+
+We found the memstore snapshotting would cost much time because of calling the time-consuming ConcurrentSkipListMap#Size, it would make the p999 latency spike happen. So in this issue, we remove all ConcurrentSkipListMap#size in memstore by counting the cellsCount in MemstoreSizeing. As the issue described, the p999 latency spike was mitigated.
+
+
+---
+
+* [HBASE-21034](https://issues.apache.org/jira/browse/HBASE-21034) | *Major* | **Add new throttle type: read/write capacity unit**
+
+Provides a new throttle type: capacity unit. One read/write/request capacity unit represents that read/write/read+write up to 1K data. If data size is more than 1K, then consume additional capacity units.
+
+Use shell command to set capacity unit(CU):
+set\_quota TYPE =\> THROTTLE, THROTTLE\_TYPE =\> WRITE, USER =\> 'u1', LIMIT =\> '10CU/sec'
+
+Use the "hbase.quota.read.capacity.unit" property to set the data size of one read capacity unit in bytes, the default value is 1K. Use the "hbase.quota.write.capacity.unit" property to set the data size of one write capacity unit in bytes, the default value is 1K.
+
+
+---
+
+* [HBASE-21595](https://issues.apache.org/jira/browse/HBASE-21595) | *Minor* | **Print thread's information and stack traces when RS is aborting forcibly**
+
+Does thread dump on stdout on abort.
+
+
+---
+
+* [HBASE-21732](https://issues.apache.org/jira/browse/HBASE-21732) | *Critical* | **Should call toUpperCase before using Enum.valueOf in some methods for ColumnFamilyDescriptor**
+
+Now all the Enum configs in ColumnFamilyDescriptor can accept lower case config value.
+
+
+---
+
+* [HBASE-21712](https://issues.apache.org/jira/browse/HBASE-21712) | *Minor* | **Make submit-patch.py python3 compatible**
+
+Python3 support was added to dev-support/submit-patch.py. To install newly required dependencies run \`pip install -r dev-support/python-requirements.txt\` command.
+
+
+---
+
+* [HBASE-21657](https://issues.apache.org/jira/browse/HBASE-21657) | *Major* | **PrivateCellUtil#estimatedSerializedSizeOf has been the bottleneck in 100% scan case.**
+
+In HBASE-21657, I simplified the path of estimatedSerialiedSize() & estimatedSerialiedSizeOfCell() by moving the general getSerializedSize()
+and heapSize() from ExtendedCell to Cell interface. The patch also included some other improvments:
+
+1. For 99% of case, our cells has no tags, so let the HFileScannerImpl just return the NoTagsByteBufferKeyValue if no tags, which means we can save
+ lots of cpu time when sending no tags cell to rpc because can just return the length instead of getting the serialize size by caculating offset/length
+ of each fields(row/cf/cq..)
+2. Move the subclass's getSerializedSize implementation from ExtendedCell to their own class, which mean we did not need to call ExtendedCell's
+ getSerialiedSize() firstly, then forward to subclass's getSerializedSize(withTags).
+3. Give a estimated result arraylist size for avoiding the frequent list extension when in a big scan, now we estimate the array size as min(scan.rows, 512).
+ it's also help a lot.
+
+We gain almost ~40% throughput improvement in 100% scan case for branch-2 (cacheHitRatio~100%)[1], it's a good thing. While it's a incompatible change in
+some case, such as if the upstream user implemented their own Cells, although it's rare but can happen, then their compile will be error.
+
+
+---
+
+* [HBASE-21647](https://issues.apache.org/jira/browse/HBASE-21647) | *Major* | **Add status track for splitting WAL tasks**
+
+Adds task monitor that shows ServerCrashProcedure progress in UI.
+
+
+---
+
+* [HBASE-21652](https://issues.apache.org/jira/browse/HBASE-21652) | *Major* | **Refactor ThriftServer making thrift2 server inherited from thrift1 server**
+
+Before this issue, thrift1 server and thrift2 server are totally different servers. If a new feature is added to thrift1 server, thrfit2 server have to make the same change to support it(e.g. authorization). After this issue, thrift2 server is inherited from thrift1, thrift2 server now have all the features thrift1 server has(e.g http support, which thrift2 server doesn't have before). The way to start thrift1 or thrift2 server remain the same after this issue.
+
+
+---
+
+* [HBASE-21661](https://issues.apache.org/jira/browse/HBASE-21661) | *Major* | **Provide Thrift2 implementation of Table/Admin**
+
+ThriftAdmin/ThriftTable are implemented based on Thrift2. With ThriftAdmin/ThriftTable, People can use thrift2 protocol just like HTable/HBaseAdmin.
+Example of using ThriftConnection
+Configuration conf = HBaseConfiguration.create();
+conf.set(ClusterConnection.HBASE\_CLIENT\_CONNECTION\_IMPL,ThriftConnection.class.getName());
+Connection conn = ConnectionFactory.createConnection(conf);
+Table table = conn.getTable(tablename)
+It is just like a normal Connection, similar use experience with the default ConnectionImplementation
+
+
+---
+
+* [HBASE-21618](https://issues.apache.org/jira/browse/HBASE-21618) | *Critical* | **Scan with the same startRow(inclusive=true) and stopRow(inclusive=false) returns one result**
+
+There was a bug when scan with the same startRow(inclusive=true) and stopRow(inclusive=false). The old incorrect behavior is return one result. After this fix, the new correct behavior is return nothing.
+
+
+---
+
+* [HBASE-21159](https://issues.apache.org/jira/browse/HBASE-21159) | *Major* | **Add shell command to switch throttle on or off**
+
+Support enable or disable rpc throttle when hbase quota is enabled. If hbase quota is enabled, rpc throttle is enabled by default. When disable rpc throttle, HBase will not throttle any request. Use the following commands to switch rpc throttle : enable\_rpc\_throttle / disable\_rpc\_throttle.
+
+
+---
+
+* [HBASE-21659](https://issues.apache.org/jira/browse/HBASE-21659) | *Minor* | **Avoid to load duplicate coprocessors in system config and table descriptor**
+
+Add a new configuration "hbase.skip.load.duplicate.table.coprocessor". The default value is false to keep compatible with the old behavior. Config it true to skip load duplicate table coprocessor.
+
+
+---
+
+* [HBASE-21650](https://issues.apache.org/jira/browse/HBASE-21650) | *Major* | **Add DDL operation and some other miscellaneous to thrift2**
+
+Added DDL operations and some other structure definition to thrift2. Methods added:
+create/modify/addColumnFamily/deleteColumnFamily/modifyColumnFamily/enable/disable/truncate/delete table
+create/modify/delete namespace
+get(list)TableDescriptor(s)/get(list)NamespaceDescirptor(s)
+tableExists/isTableEnabled/isTableDisabled/isTableAvailabe
+And some class definitions along with those methods
+
+
+---
+
+* [HBASE-21643](https://issues.apache.org/jira/browse/HBASE-21643) | *Major* | **Introduce two new region coprocessor method and deprecated postMutationBeforeWAL**
+
+Deprecated region coprocessor postMutationBeforeWAL and introduce two new region coprocessor postIncrementBeforeWAL and postAppendBeforeWAL instead.
+
+
+---
+
+* [HBASE-21635](https://issues.apache.org/jira/browse/HBASE-21635) | *Major* | **Use maven enforcer to ban imports from illegal packages**
+
+Use de.skuzzle.enforcer.restrict-imports-enforcer-rule extension for maven enforcer plugin to ban illegal imports at compile time. Now if you use illegal imports, for example, import com.google.common.\*, there will be a compile error, instead of a checkstyle warning.
+
+
+---
+
+* [HBASE-21401](https://issues.apache.org/jira/browse/HBASE-21401) | *Critical* | **Sanity check when constructing the KeyValue**
+
+Add a sanity check when constructing KeyValue from a byte[]. we use the constructor when we're reading kv from socket or HFIle or WAL(replication). the santiy check isn't designed for discovering the bits corruption in network transferring or disk IO. It is designed to detect bugs inside HBase in advance. and HBASE-21459 indicated that there's extremely small performance loss for diff kinds of keyvalue.
+
+
+---
+
+* [HBASE-21554](https://issues.apache.org/jira/browse/HBASE-21554) | *Minor* | **Show replication endpoint classname for replication peer on master web UI**
+
+The replication UI on master will show the replication endpoint classname.
+
+
+---
+
+* [HBASE-21549](https://issues.apache.org/jira/browse/HBASE-21549) | *Major* | **Add shell command for serial replication peer**
+
+Add a SERIAL flag for add\_peer command to identifiy whether or not the replication peer is a serial replication peer. The default serial flag is false.
+
+
+---
+
+* [HBASE-21453](https://issues.apache.org/jira/browse/HBASE-21453) | *Major* | **Convert ReadOnlyZKClient to DEBUG instead of INFO**
+
+Log level of ReadOnlyZKClient moved to debug.
+
+
+---
+
+* [HBASE-21283](https://issues.apache.org/jira/browse/HBASE-21283) | *Minor* | **Add new shell command 'rit' for listing regions in transition**
+
+<!-- markdown -->
+
+The HBase `shell` now includes a command to list regions currently in transition.
+
+```
+HBase Shell
+Use "help" to get list of supported commands.
+Use "exit" to quit this interactive shell.
+Version 1.5.0-SNAPSHOT, r9bb6d2fa8b760f16cd046657240ebd4ad91cb6de, Mon Oct 8 21:05:50 UTC 2018
+
+hbase(main):001:0> help 'rit'
+List all regions in transition.
+Examples:
+ hbase> rit
+
+hbase(main):002:0> create ...
+0 row(s) in 2.5150 seconds
+=> Hbase::Table - IntegrationTestBigLinkedList
+
+hbase(main):003:0> rit
+0 row(s) in 0.0340 seconds
+
+hbase(main):004:0> unassign '56f0c38c81ae453d19906ce156a2d6a1'
+0 row(s) in 0.0540 seconds
+
+hbase(main):005:0> rit
+IntegrationTestBigLinkedList,L\xCC\xCC\xCC\xCC\xCC\xCC\xCB,1539117183224.56f0c38c81ae453d19906ce156a2d6a1. state=PENDING_CLOSE, ts=Tue Oct 09 20:33:34 UTC 2018 (0s ago), server=null
+1 row(s) in 0.0170 seconds
+```
+
+
+---
+
+* [HBASE-21567](https://issues.apache.org/jira/browse/HBASE-21567) | *Major* | **Allow overriding configs starting up the shell**
+
+Allow passing of -Dkey=value option to shell to override hbase-\* configuration: e.g.:
+
+$ ./bin/hbase shell -Dhbase.zookeeper.quorum=ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org -Draining=false
+...
+hbase(main):001:0\> @shell.hbase.configuration.get("hbase.zookeeper.quorum")
+=\> "ZK0.remote.cluster.example.org,ZK1.remote.cluster.example.org,ZK2.remote.cluster.example.org"
+hbase(main):002:0\> @shell.hbase.configuration.get("raining")
+=\> "false"
+
+
+---
+
+* [HBASE-21560](https://issues.apache.org/jira/browse/HBASE-21560) | *Major* | **Return a new TableDescriptor for MasterObserver#preModifyTable to allow coprocessor modify the TableDescriptor**
+
+Incompatible change. Allow MasterObserver#preModifyTable to return a new TableDescriptor. And master will use this returned TableDescriptor to modify table.
+
+
+---
+
+* [HBASE-21551](https://issues.apache.org/jira/browse/HBASE-21551) | *Blocker* | **Memory leak when use scan with STREAM at server side**
+
+<!-- markdown -->
+### Summary
+HBase clusters will experience Region Server failures due to out of memory errors due to a leak given any of the following:
+
+* User initiates Scan operations set to use the STREAM reading type
+* User initiates Scan operations set to use the default reading type that read more than 4 * the block size of column families involved in the scan (e.g. by default 4*64KiB)
+* Compactions run
+
+### Root cause
+
+When there are long running scans the Region Server process attempts to optimize access by using a different API geared towards sequential access. Due to an error in HBASE-20704 for HBase 2.0+ the Region Server fails to release related resources when those scans finish. That same optimization path is always used for the HBase internal file compaction process.
+
+### Workaround
+
+Impact for this error can be minimized by setting the config value “hbase.storescanner.pread.max.bytes” to MAX_INT to avoid the optimization for default user scans. Clients should also be checked to ensure they do not pass the STREAM read type to the Scan API. This will have a severe impact on performance for long scans.
+
+Compactions always use this sequential optimized reading mechanism so downstream users will need to periodically restart Region Server roles after compactions have happened.
+
+
+---
+
+* [HBASE-21550](https://issues.apache.org/jira/browse/HBASE-21550) | *Major* | **Add a new method preCreateTableRegionInfos for MasterObserver which allows CPs to modify the TableDescriptor**
+
+Add a new method preCreateTableRegionInfos for MasterObserver, which will be called before creating region infos for the given table, before the preCreateTable method. It allows you to return a new TableDescritor to override the original one. Returns null or throws exception will stop the creation.
+
+
+---
+
+* [HBASE-21492](https://issues.apache.org/jira/browse/HBASE-21492) | *Critical* | **CellCodec Written To WAL Before It's Verified**
+
+After HBASE-21492 the return type of WALCellCodec#getWALCellCodecClass has been changed from String to Class
+
+
+---
+
+* [HBASE-21387](https://issues.apache.org/jira/browse/HBASE-21387) | *Major* | **Race condition surrounding in progress snapshot handling in snapshot cache leads to loss of snapshot files**
+
+To prevent race condition between in progress snapshot (performed by TakeSnapshotHandler) and HFileCleaner which results in data loss, this JIRA introduced mutual exclusion between taking snapshot and running HFileCleaner. That is, at any given moment, either some snapshot can be taken or, HFileCleaner checks hfiles which are not referenced, but not both can be running.
+
+
+---
+
+* [HBASE-21452](https://issues.apache.org/jira/browse/HBASE-21452) | *Major* | **Illegal character in hbase counters group name**
+
+Changes group name of hbase metrics from "HBase Counters" to "HBaseCounters".
+
+
+---
+
+* [HBASE-21443](https://issues.apache.org/jira/browse/HBASE-21443) | *Major* | **[hbase-connectors] Purge hbase-\* modules from core now they've been moved to hbase-connectors**
+
+Parent issue moved hbase-spark\* modules to hbase-connectors. This issue removes hbase-spark\* modules from hbase core repo.
+
+
+---
+
+* [HBASE-21430](https://issues.apache.org/jira/browse/HBASE-21430) | *Major* | **[hbase-connectors] Move hbase-spark\* modules to hbase-connectors repo**
+
+hbase-spark\* modules have been cloned to https://github.com/apache/hbase-connectors All spark connector dev is to happen in that repo from here on out.
+
+Let me file a subtask to remove hbase-spark\* modules from hbase core.
+
+
+---
+
+* [HBASE-21417](https://issues.apache.org/jira/browse/HBASE-21417) | *Critical* | **Pre commit build is broken due to surefire plugin crashes**
+
+Add -Djdk.net.URLClassPath.disableClassPathURLCheck=true when executing surefire plugin.
+
+
+---
+
+* [HBASE-21191](https://issues.apache.org/jira/browse/HBASE-21191) | *Major* | **Add a holding-pattern if no assign for meta or namespace (Can happen if masterprocwals have been cleared).**
+
+Puts master startup into holding pattern if meta is not assigned (previous it would exit). To make progress again, operator needs to inject an assign (Caveats and instruction can be found in HBASE-21035).
+
+
+---
+
+* [HBASE-21322](https://issues.apache.org/jira/browse/HBASE-21322) | *Critical* | **Add a scheduleServerCrashProcedure() API to HbckService**
+
+Adds scheduleServerCrashProcedure to the HbckService.
+
+
+---
+
+* [HBASE-21325](https://issues.apache.org/jira/browse/HBASE-21325) | *Major* | **Force to terminate regionserver when abort hang in somewhere**
+
+Add two new config hbase.regionserver.abort.timeout and hbase.regionserver.abort.timeout.task. If regionserver abort timeout, it will schedule an abort timeout task to run. The default abort task is SystemExitWhenAbortTimeout, which will force to terminate region server when abort timeout. And you can config a special abort timeout task by hbase.regionserver.abort.timeout.task.
+
+
+---
+
+* [HBASE-21215](https://issues.apache.org/jira/browse/HBASE-21215) | *Major* | **Figure how to invoke hbck2; make it easy to find**
+
+Adds to bin/hbase means of invoking hbck2. Pass the new '-j' option on the 'hbck' command with a value of the full path to the HBCK2.jar.
+
+E.g:
+
+$ ./bin/hbase hbck -j ~/checkouts/hbase-operator-tools/hbase-hbck2/target/hbase-hbck2-1.0.0-SNAPSHOT.jar setTableState x ENABLED
+
+
+---
+
+* [HBASE-21372](https://issues.apache.org/jira/browse/HBASE-21372) | *Major* | **Set hbase.assignment.maximum.attempts to Long.MAX**
+
+Retry assigns 'forever' (or until an intervention such as a ServerCrashProcedure).
+
+Previous retry was a maximum of ten times but on failure, handling was an indeterminate.
+
+
+---
+
+* [HBASE-21338](https://issues.apache.org/jira/browse/HBASE-21338) | *Major* | **[balancer] If balancer is an ill-fit for cluster size, it gives little indication**
+
+The description claims the balancer not dynamically configurable but this is an error; it is http://hbase.apache.org/book.html#dyn\_config
+
+Also, if balancer is seen to be cutting out too soon, try setting "hbase.master.balancer.stochastic.runMaxSteps" to true.
+
+Adds cleaner logging around balancer start.
+
+
+---
+
+* [HBASE-21073](https://issues.apache.org/jira/browse/HBASE-21073) | *Major* | **"Maintenance mode" master**
+
+ Instead of being an ephemeral state set by hbck, maintenance mode is now
+ an explicit toggle set by either configuration property or environment
+ variable. In maintenance mode, master will host system tables and not
+ assign any user-space tables to RSs. This gives operators the ability to
+ affect repairs to meta table with fewer moving parts.
+
+
+---
+
+* [HBASE-21335](https://issues.apache.org/jira/browse/HBASE-21335) | *Critical* | **Change the default wait time of HBCK2 tool**
+
+Changed waitTime parameter to lockWait on bypass. Changed default waitTime from 0 -- i.e. wait for ever -- to 1ms so if lock is held, we'll go past it and if override enforce bypass.
+
+
+---
+
+* [HBASE-21291](https://issues.apache.org/jira/browse/HBASE-21291) | *Major* | **Add a test for bypassing stuck state-machine procedures**
+
+bypass will now throw an Exception if passed a lockWait \<= 0; i.e bypass will prevent an operator getting stuck on an entity lock waiting forever (lockWait == 0)
+
+
+---
+
+* [HBASE-21320](https://issues.apache.org/jira/browse/HBASE-21320) | *Major* | **[canary] Cleanup of usage and add commentary**
+
+Cleans up usage and docs around Canary. Does not change command-line args (though we should -- smile).
+
+
+---
+
+* [HBASE-21278](https://issues.apache.org/jira/browse/HBASE-21278) | *Critical* | **Do not rollback successful sub procedures when rolling back a procedure**
+
+For the sub procedures which are successfully finished, do not do rollback. This is a change in rollback behavior.
+
+State changes which are done by sub procedures should be handled by parent procedures when rolling back. For example, when rolling back a MergeTableProcedure, we will schedule new procedures to bring the offline regions online instead of rolling back the original procedures which off-lined the regions (in fact these procedures can not be rolled back...).
+
+
+---
+
+* [HBASE-21158](https://issues.apache.org/jira/browse/HBASE-21158) | *Critical* | **Empty qualifier cell should not be returned if it does not match QualifierFilter**
+
+<!-- markdown -->
+
+Scans that make use of `QualifierFilter` previously would erroneously return both columns with an empty qualifier along with those that matched. After this change that behavior has changed to only return those columns that match.
+
+
+---
+
+* [HBASE-21098](https://issues.apache.org/jira/browse/HBASE-21098) | *Major* | **Improve Snapshot Performance with Temporary Snapshot Directory when rootDir on S3**
+
+It is recommended to place the working directory on-cluster on HDFS as doing so has shown a strong performance increase due to data locality. It is important to note that the working directory should not overlap with any existing directories as the working directory will be cleaned out during the snapshot process. Beyond that, any well-named directory on HDFS should be sufficient.
+
+
+---
+
+* [HBASE-21185](https://issues.apache.org/jira/browse/HBASE-21185) | *Minor* | **WALPrettyPrinter: Additional useful info to be printed by wal printer tool, for debugability purposes**
+
+This adds two extra features to WALPrettyPrinter tool:
+
+1) Output for each cell combined size of cell descriptors, plus the cell value itself, in a given WAL edit. This is printed on the results as "cell total size sum:" info by default;
+
+2) An optional -g/--goto argument, that allows to seek straight to that specific WAL file position, then sequentially reading the WAL from that point towards its end;
+
+
+---
+
+* [HBASE-21287](https://issues.apache.org/jira/browse/HBASE-21287) | *Major* | **JVMClusterUtil Master initialization wait time not configurable**
+
+Local HBase cluster (as used by unit tests) wait times on startup and initialization can be configured via \`hbase.master.start.timeout.localHBaseCluster\` and \`hbase.master.init.timeout.localHBaseCluster\`
+
+
+---
+
+* [HBASE-21280](https://issues.apache.org/jira/browse/HBASE-21280) | *Trivial* | **Add anchors for each heading in UI**
+
+Adds anchors #tables, #tasks, etc.
+
+
+---
+
+* [HBASE-21232](https://issues.apache.org/jira/browse/HBASE-21232) | *Major* | **Show table state in Tables view on Master home page**
+
+Add table state column to the tables panel
+
+
+---
+
+* [HBASE-21223](https://issues.apache.org/jira/browse/HBASE-21223) | *Critical* | **[amv2] Remove abort\_procedure from shell**
+
+Removed the abort\_procedure command from shell -- dangerous -- and deprecated abortProcedure in Admin API.
+
+
+---
+
+* [HBASE-20636](https://issues.apache.org/jira/browse/HBASE-20636) | *Major* | **Introduce two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED**
+
+Add two bloom filter type : ROWPREFIX\_FIXED\_LENGTH and ROWPREFIX\_DELIMITED
+1. ROWPREFIX\_FIXED\_LENGTH: specify the length of the prefix
+2. ROWPREFIX\_DELIMITED: specify the delimiter of the prefix
+Need to specify parameters for these two types of bloomfilter, otherwise the table will fail to create
+Example:
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_FIXED\_LENGTH', CONFIGURATION =\> {'RowPrefixBloomFilter.prefix\_length' =\> '10'}}
+create 't1', {NAME =\> 'f1', BLOOMFILTER =\> 'ROWPREFIX\_DELIMITED', CONFIGURATION =\> {'RowPrefixDelimitedBloomFilter.delimiter' =\> '#'}}
+
+
+---
+
+* [HBASE-21156](https://issues.apache.org/jira/browse/HBASE-21156) | *Critical* | **[hbck2] Queue an assign of hbase:meta and bulk assign/unassign**
+
+Adds 'raw' assigns/unassigns to the Hbck Service. Takes a list of encoded region names and bulk assigns/unassigns. Skirts Master 'state' check and does not invoke Coprocessors. For repair only.
+
+Here is what HBCK2 usage looks like now:
+
+{code}
+$ java -cp hbase-hbck2-1.0.0-SNAPSHOT.jar org.apache.hbase.HBCK2
+usage: HBCK2 \<OPTIONS\> COMMAND [\<ARGS\>]
+
+Options:
+ -d,--debug run with debug output
+ -h,--help output this help message
+ --hbase.zookeeper.peerport peerport of target hbase ensemble
+ --hbase.zookeeper.quorum ensemble of target hbase
+ --zookeeper.znode.parent parent znode of target hbase
+
+Commands:
+ setTableState \<TABLENAME\> \<STATE\>
+ Possible table states: ENABLED, DISABLED, DISABLING, ENABLING
+ To read current table state, in the hbase shell run:
+ hbase\> get 'hbase:meta', '\<TABLENAME\>', 'table:state'
+ A value of \\x08\\x00 == ENABLED, \\x08\\x01 == DISABLED, etc.
+ An example making table name 'user' ENABLED:
+ $ HBCK2 setTableState users ENABLED
+ Returns whatever the previous table state was.
+
+ assign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' assign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ e.g. 1588230740 is hard-coded encoding for hbase:meta region and
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 assign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created AssignProcedure or -1 if none.
+
+ unassign \<ENCODED\_REGIONNAME\> ...
+ A 'raw' unassign that can be used even during Master initialization.
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ Skirts Coprocessors. Pass one or more encoded RegionNames:
+ de00010733901a05f5a2a3a382e27dd4 is an example of what a random
+ user-space encoded Region name looks like. For example:
+ $ HBCK2 unassign 1588230740 de00010733901a05f5a2a3a382e27dd4
+ Returns the pid of the created UnassignProcedure or -1 if none.
+{code}
+
+
+---
+
+* [HBASE-21021](https://issues.apache.org/jira/browse/HBASE-21021) | *Major* | **Result returned by Append operation should be ordered**
+
+This change ensures Append operations are assembled into the expected order.
+
+
+---
+
+* [HBASE-21171](https://issues.apache.org/jira/browse/HBASE-21171) | *Major* | **[amv2] Tool to parse a directory of MasterProcWALs standalone**
+
+Make it so can run the WAL parse and load system in isolation. Here is an example:
+
+{code}$ HBASE\_OPTS=" -XX:+UnlockDiagnosticVMOptions -XX:+UnlockCommercialFeatures -XX:+FlightRecorder -XX:+DebugNonSafepoints" ./bin/hbase org.apache.hadoop.hbase.procedure2.store.wal.WALProcedureStore ~/big\_set\_of\_masterprocwals/
+{code}
+
+
+---
+
+* [HBASE-21107](https://issues.apache.org/jira/browse/HBASE-21107) | *Minor* | **add a metrics for netty direct memory**
+
+Add a new nettyDirectMemoryUsage under server's ipc metrics to show direct memory usage for netty rpc server.
+
+
+---
+
+* [HBASE-21153](https://issues.apache.org/jira/browse/HBASE-21153) | *Major* | **Shaded client jars should always build in relevant phase to avoid confusion**
+
+Client facing artifacts are now built whenever Maven is run through the "package" goal. Previously, the client facing artifacts would create placeholder jars that skipped repackaging HBase and third-party dependencies unless the "release" profile was active.
+
+Build times may be noticeably longer depending on your build hardware. For example, the Jenkins worker nodes maintained by ASF Infra take ~14% longer to do a full packaging build. An example portability-focused personal laptop took ~25% longer.
+
+
+---
+
+* [HBASE-20942](https://issues.apache.org/jira/browse/HBASE-20942) | *Major* | **Improve RpcServer TRACE logging**
+
+Allows configuration of the length of RPC messages printed to the log at TRACE level via "hbase.ipc.trace.param.size" in RpcServer.
+
+
+---
+
+* [HBASE-20649](https://issues.apache.org/jira/browse/HBASE-20649) | *Minor* | **Validate HFiles do not have PREFIX\_TREE DataBlockEncoding**
+
+<!-- markdown -->
+Users who have previously made use of prefix tree encoding can now check that their existing HFiles no longer contain data that uses it with an additional preupgrade check command.
+
+```
+hbase pre-upgrade validate-hfile
+```
+
+Please see the "HFile Content validation" section of the ref guide's coverage of the pre-upgrade validator tool for usage details.
+
+
+---
+
+* [HBASE-20941](https://issues.apache.org/jira/browse/HBASE-20941) | *Major* | **Create and implement HbckService in master**
+
+Adds an HBCK Service and a first method to force-change-in-table-state for use by an HBCK client effecting 'repair' to a malfunctioning HBase.
+
+
+---
+
+* [HBASE-21071](https://issues.apache.org/jira/browse/HBASE-21071) | *Major* | **HBaseTestingUtility::startMiniCluster() to use builder pattern**
+
+Cleanup all the cluster start override combos in HBaseTestingUtility by adding a StartMiniClusterOption and Builder.
+
+
+---
+
+* [HBASE-21072](https://issues.apache.org/jira/browse/HBASE-21072) | *Major* | **Block out HBCK1 in hbase2**
+
+Fence out hbase-1.x hbck1 instances. Stop them making state changes on an hbase-2.x cluster; they could do damage. We do this by writing the hbck1 lock file into place on hbase-2.x Master start-up.
+
+To disable this new behavior, set hbase.write.hbck1.lock.file to false
+
+
+---
+
+* [HBASE-20881](https://issues.apache.org/jira/browse/HBASE-20881) | *Major* | **Introduce a region transition procedure to handle all the state transition for a region**
+
+Introduced a new TransitRegionStateProcedure to replace the old AssignProcedure/UnassignProcedure/MoveRegionProcedure. In the old code, MRP will not be attached to RegionStateNode, so it can not be interrupted by ServerCrashProcedure, which introduces lots of tricky code to deal with races, and also causes lots of other difficulties on how to prevent scheduling redundant or even conflict procedures for a region.
+
+And now TRSP is the only one procedure which can bring region online or offline. When you want to schedule one, you need to check whether there is already one attached to the RegionStateNode, under the lock of the RegionStateNode. If not just go ahead, and if there is one, then you should do something, for example, give up and fail directly, or tell the TRSP to give up(This is what SCP does). Since the check and attach are both under the lock of RSN, it will greatly reduce the possible r [...]
+
+
+---
+
+* [HBASE-21012](https://issues.apache.org/jira/browse/HBASE-21012) | *Critical* | **Revert the change of serializing TimeRangeTracker**
+
+HFiles generated by 2.0.0, 2.0.1, 2.1.0 are not forward compatible to 1.4.6-, 1.3.2.1-, 1.2.6.1-, and other inactive releases. Why HFile lose compatability is hbase in new versions (2.0.0, 2.0.1, 2.1.0) use protobuf to serialize/deserialize TimeRangeTracker (TRT) while old versions use DataInput/DataOutput. To solve this, We have to put HBASE-21012 to 2.x and put HBASE-21013 in 1.x. For more information, please check HBASE-21008.
+
+
+---
+
+* [HBASE-20965](https://issues.apache.org/jira/browse/HBASE-20965) | *Major* | **Separate region server report requests to new handlers**
+
+After HBASE-20965, we can use MasterFifoRpcScheduler in master to separate RegionServerReport requests to indenpedent handler. To use this feature, please set "hbase.master.rpc.scheduler.factory.class" to
+ "org.apache.hadoop.hbase.ipc.MasterFifoRpcScheduler". Use "hbase.master.server.report.handler.count" to set RegionServerReport handlers count, the default value is half of "hbase.regionserver.handler.count" value, but at least 1, and the other handlers count in master is "hbase.regionserver.handler.count" value minus RegionServerReport handlers count, but at least 1 too.
+
+
+---
+
+* [HBASE-20813](https://issues.apache.org/jira/browse/HBASE-20813) | *Minor* | **Remove RPC quotas when the associated table/Namespace is dropped off**
+
+In previous releases, when a Space Quota was configured on a table or namespace and that table or namespace was deleted, the Space Quota was also deleted. This change improves the implementation so that the same is also done for RPC Quotas.
+
+
+---
+
+* [HBASE-20986](https://issues.apache.org/jira/browse/HBASE-20986) | *Major* | **Separate the config of block size when we do log splitting and write Hlog**
+
+After HBASE-20986, we can set different value to block size of WAL and recovered edits. Both of their default value is 2 \* default HDFS blocksize. And hbase.regionserver.recoverededits.blocksize is for block size of recovered edits while hbase.regionserver.hlog.blocksize is for block size of WAL.
+
+
+---
+
+* [HBASE-20856](https://issues.apache.org/jira/browse/HBASE-20856) | *Minor* | **PITA having to set WAL provider in two places**
+
+With this change if a WAL's meta provider (hbase.wal.meta\_provider) is not explicitly set, it now defaults to whatever hbase.wal.provider is set to. Previous, the two settings operated independently, each with its own default.
+
+This change is operationally incompatible with previous HBase versions because the default WAL meta provider no longer defaults to AsyncFSWALProvider but to hbase.wal.provider.
+
+The thought is that this is more in line with an operator's expectation, that a change in hbase.wal.provider is sufficient to change how WALs are written, especially given hbase.wal.meta\_provider is an obscure configuration and that the very idea that meta regions would have their own wal provider would likely come as a surprise.
+
+
+---
+
+* [HBASE-20538](https://issues.apache.org/jira/browse/HBASE-20538) | *Critical* | **Upgrade our hadoop versions to 2.7.7 and 3.0.3**
+
+Update hadoop-two.version to 2.7.7 and hadoop-three.version to 3.0.3 due to a JDK issue which is solved by HADOOP-15473.
+
+
+---
+
+* [HBASE-20846](https://issues.apache.org/jira/browse/HBASE-20846) | *Major* | **Restore procedure locks when master restarts**
+
+1. Make hasLock method final, and add a locked field in Procedure to record whether we have the lock. We will set it to true in doAcquireLock and to false in doReleaseLock. The sub procedures do not need to manage it any more.
+
+2. Also added a locked field in the proto message. When storing, the field will be set according to the return value of hasLock. And when loading, there is a new field in Procedure called lockedWhenLoading. We will set it to true if the locked field in proto message is true.
+
+3. The reason why we can not set the locked field directly to true by calling doAcquireLock is that, during initialization, most procedures need to wait until master is initialized. So the solution here is that, we introduced a new method called waitInitialized in Procedure, and move the wait master initialized related code from acquireLock to this method. And we added a restoreLock method to Procedure, if lockedWhenLoading is true, we will call the acquireLock to get the lock, but do no [...]
+
+
+---
+
+* [HBASE-20672](https://issues.apache.org/jira/browse/HBASE-20672) | *Minor* | **New metrics ReadRequestRate and WriteRequestRate**
+
+Exposing 2 new metrics in HBase to provide ReadRequestRate and WriteRequestRate at region server level. These metrics give the rate of request handled by the region server and are reset after every monitoring interval.
+
+
+---
+
+* [HBASE-6028](https://issues.apache.org/jira/browse/HBASE-6028) | *Minor* | **Implement a cancel for in-progress compactions**
+
+Added a new command to the shell to switch on/off compactions called "compaction\_switch". Disabling compactions will interrupt any currently ongoing compactions. This setting will be lost on restart of the server. Added the configuration hbase.regionserver.compaction.enabled so user can enable/disable compactions via hbase-site.xml.
+
+
+---
+
+* [HBASE-20884](https://issues.apache.org/jira/browse/HBASE-20884) | *Major* | **Replace usage of our Base64 implementation with java.util.Base64**
+
+Class org.apache.hadoop.hbase.util.Base64 has been removed in it's entirety from HBase 2+. In HBase 1, unused methods have been removed from the class and the audience was changed from Public to Private. This class was originally intended as an internal utility class that could be used externally but thinking since changed; these classes should not have been advertised as public to end-users.
+
+This represents an incompatible change for users who relied on this implementation. An alternative implementation for affected clients is available at java.util.Base64 when using Java 8 or newer; be aware, it may encode/decode differently. For clients seeking to restore this specific implementation, it is available in the public domain for download at http://iharder.sourceforge.net/current/java/base64/
+
+
+---
+
+* [HBASE-20357](https://issues.apache.org/jira/browse/HBASE-20357) | *Major* | **AccessControlClient API Enhancement**
+
+This enhances the AccessControlClient APIs to retrieve the permissions based on namespace, table name, family and qualifier for specific user. AccessControlClient can also validate a user whether allowed to perform specified operations on a particular table.
+Following APIs have been added,
+1) getUserPermissions(Connection connection, String tableRegex, byte[] columnFamily, byte[] columnQualifier, String userName)
+ Scope of retrieving permission will be same as existing.
+2) hasPermission(onnection connection, String tableName, byte[] columnFamily, byte[] columnQualifier, String userName, Permission.Action... actions)
+ Scope of validating user privilege,
+ User can perform self check without any special privilege but ADMIN privilege will be required to perform check for other users.
+ For example, suppose there are two users "userA" & "userB" then there can be below scenarios,
+ a. When userA want to check whether userA have privilege to perform mentioned actions
+ userA don't need ADMIN privilege, as it's a self query.
+ b. When userA want to check whether userB have privilege to perform mentioned actions,
+ userA must have ADMIN or superuser privilege, as it's trying to query for other user.
+
+
+
+### Summary
+HBase clusters will experience Region Server failures due to out of memory errors due to a leak given any of the following:
+
+* User initiates Scan operations set to use the STREAM reading type
+* User initiates Scan operations set to use the default reading type that read more than 4 * the block size of column families involved in the scan (e.g. by default 4*64KiB)
+* Compactions run
+
+### Root cause
+
+When there are long running scans the Region Server process attempts to optimize access by using a different API geared towards sequential access. Due to an error in HBASE-20704 for HBase 2.0+ the Region Server fails to release related resources when those scans finish. That same optimization path is always used for the HBase internal file compaction process.
+
+### Workaround
+
+Impact for this error can be minimized by setting the config value “hbase.storescanner.pread.max.bytes” to MAX_INT to avoid the optimization for default user scans. Clients should also be checked to ensure they do not pass the STREAM read type to the Scan API. This will have a severe impact on performance for long scans.
+
+Compactions always use this sequential optimized reading mechanism so downstream users will need to periodically restart Region Server roles after compactions have happened.
+
+
+---
+
+* [HBASE-21550](https://issues.apache.org/jira/browse/HBASE-21550) | *Major* | **Add a new method preCreateTableRegionInfos for MasterObserver which allows CPs to modify the TableDescriptor**
+
+Add a new method preCreateTableRegionInfos for MasterObserver, which will be called before creating region infos for the given table, before the preCreateTable method. It allows you to return a new TableDescritor to override the original one. Returns null or throws exception will stop the creation.
+
+
+---
+
+* [HBASE-21492](https://issues.apache.org/jira/browse/HBASE-21492) | *Critical* | **CellCodec Written To WAL Before It's Verified**
+
+After HBASE-21492 the return type of WALCellCodec#getWALCellCodecClass has been changed from String to Class
+
+
+---
+
+* [HBASE-21387](https://issues.apache.org/jira/browse/HBASE-21387) | *Major* | **Race condition surrounding in progress snapshot handling in snapshot cache leads to loss of snapshot files**
+
+To prevent race condition between in progress snapshot (performed by TakeSnapshotHandler) and HFileCleaner which results in data loss, this JIRA introduced mutual exclusion between taking snapshot and running HFileCleaner. That is, at any given moment, either some snapshot can be taken or, HFileCleaner checks hfiles which are not referenced, but not both can be running.
+
+
+---
+
+* [HBASE-21452](https://issues.apache.org/jira/browse/HBASE-21452) | *Major* | **Illegal character in hbase counters group name**
+
+Changes group name of hbase metrics from "HBase Counters" to "HBaseCounters".
+
+
+---
+
+* [HBASE-21443](https://issues.apache.org/jira/browse/HBASE-21443) | *Major* | **[hbase-connectors] Purge hbase-\* modules from core now they've been moved to hbase-connectors**
+
+Parent issue moved hbase-spark\* modules to hbase-connectors. This issue removes hbase-spark\* modules from hbase core repo.
+
+
+---
+
+* [HBASE-21430](https://issues.apache.org/jira/browse/HBASE-21430) | *Major* | **[hbase-connectors] Move hbase-spark\* modules to hbase-connectors repo**
+
+hbase-spark\* modules have been cloned to https://github.com/apache/hbase-connectors All spark connector dev is to happen in that repo from here on out.
+
+Let me file a subtask to remove hbase-spark\* modules from hbase core.
+
+
+---
+
+* [HBASE-21417](https://issues.apache.org/jira/browse/HBASE-21417) | *Critical* | **Pre commit build is broken due to surefire plugin crashes**
+
+Add -Djdk.net.URLClassPath.disableClassPathURLCheck=true when executing surefire plugin.
+
+
+---
+
+* [HBASE-21191](https://issues.apache.org/jira/browse/HBASE-21191) | *Major* | **Add a holding-pattern if no assign for meta or namespace (Can happen if masterprocwals have been cleared).**
+
+Puts master startup into holding pattern if meta is not assigned (previous it would exit). To make progress again, operator needs to inject an assign (Caveats and instruction can be found in HBASE-21035).
+
+
+---
+
+* [HBASE-21322](https://issues.apache.org/jira/browse/HBASE-21322) | *Critical* | **Add a scheduleServerCrashProcedure() API to HbckService**
+
+Adds scheduleServerCrashProcedure to the HbckService.
+
+
+---
+
+* [HBASE-21325](https://issues.apache.org/jira/browse/HBASE-21325) | *Major* | **Force to terminate regionserver when abort hang in somewhere**
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