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Posted to commits@hbase.apache.org by st...@apache.org on 2019/02/28 11:23:56 UTC
svn commit: r32699 [3/4] - in /dev/hbase/2.0.5RC0: ./ CHANGES.md
RELEASENOTES.md hbase-2.0.5-bin.tar.gz hbase-2.0.5-bin.tar.gz.asc
hbase-2.0.5-bin.tar.gz.sha512 hbase-2.0.5-src.tar.gz
hbase-2.0.5-src.tar.gz.asc hbase-2.0.5-src.tar.gz.sha512
Added: dev/hbase/2.0.5RC0/RELEASENOTES.md
==============================================================================
--- dev/hbase/2.0.5RC0/RELEASENOTES.md (added)
+++ dev/hbase/2.0.5RC0/RELEASENOTES.md Thu Feb 28 11:23:56 2019
@@ -0,0 +1,10204 @@
+# RELEASENOTES
+
+<!---
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+
+CHANGES.md and RELEASENOTES.md were generated using yetus releasedocmaker.
+
+First make sure what is in JIRA agrees with what is in git and vice-versa
+(See HBASE-14025 for original exposition on how to do this followed by
+the travails of various release managers. See also HBASE-18828 for a
+deriviative makes the move to yetus releasedocmaker).
+
+Then make sure that anything in current release as noted in JIRA has
+not made it out in earlier major/minor (see HBASE-14025 for how to
+reconcile which).
+
+Obtain a yetus release (see HBASE-18828 for some help). To run
+releasedocmaker, do as follows (below example is for hbase-2.0.0
+and yetus 0.9.0):
+
+ $ ./bin/releasedocmaker -p HBASE --fileversions -v 2.0.5 -l \
+ --sortorder=newer --skip-credits
+
+or on older yetus versions:
+
+ $ ./release-doc-maker/releasedocmaker.py -p HBASE --fileversions \
+ -v 2.0.0 -l --sortorder=newer --skip-credits
+
+Rename the output as CHANGES.md and RELEASENOTES.md. Edit both to put
+document title above the apache license so markdown readers work. You
+may have to bulk import old-style CHANGES.txt on to the end in a code
+comment to preserve continuity of the CHANGELOG.
+
+-->
+# HBASE 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+
+# HBASE 2.0.4 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-21551](https://issues.apache.org/jira/browse/HBASE-21551) | *Blocker* | **Memory leak when use scan with STREAM at server side**
+
+<!-- markdown -->
+# HBASE 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+### 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 âhbase.storescanner.pread.max.bytesâ 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-21146](https://issues.apache.org/jira/browse/HBASE-21146) | *Minor* | **(2.0) Add ability for HBase Canary to ignore a configurable number of ZooKeeper down nodes**
+
+Adds -permittedZookeeperFailures \<N\>
+
+Makes it so Canary will keep running reporting on downed zk ensemble members rather than exit.
+
+
+---
+
+* [HBASE-21557](https://issues.apache.org/jira/browse/HBASE-21557) | *Major* | **Set version to 2.0.4 on branch-2.0 so can cut an RC**
+
+Set project version to 2.0.4 from 2.0.4-SNAPSHOT
+
+
+---
+
+* [HBASE-21544](https://issues.apache.org/jira/browse/HBASE-21544) | *Major* | **Backport HBASE-20734 Colocate recovered edits directory with hbase.wal.dir**
+
+This change moves the recovered.edits files which are created by the WALSplitter from the default filesystem into the WAL filesystem. This better enables the separate filesystem for WAL and HFile deployment model, by avoiding a check which requires that the HFile filesystem provides the hflush capability.
+
+
+
+# HBASE 2.0.3 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [HBASE-21496](https://issues.apache.org/jira/browse/HBASE-21496) | *Major* | **Set version to 2.0.3 on branch-2.0 in prep for first RC**
+
+Changed version on branch-2.0 from 2.0.2 to 2.0.3.
+
+
+---
+
+* [HBASE-21423](https://issues.apache.org/jira/browse/HBASE-21423) | *Major* | **Procedures for meta table/region should be able to execute in separate workers**
+
+The procedure for meta table will be executed in a separate worker thread named 'Urgent Worker' to avoid stuck. A new config named 'hbase.master.urgent.procedure.threads' is added, the default value for it is 1. To disable the separate worker, set it to 0.
+
+
+---
+
+* [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-21237](https://issues.apache.org/jira/browse/HBASE-21237) | *Blocker* | **Use CompatRemoteProcedureResolver to dispatch open/close region requests to RS**
+
+Use CompatRemoteProcedureResolver instead of ExecuteProceduresRemoteCall to dispatch region open/close requests to RS. Since ExecuteProceduresRemoteCall will group all the open/close operations in one call and execute them sequentially on the target RS. If one operation fails, all the operation will be marked as failure.
+
+
+---
+
+* [HBASE-21322](https://issues.apache.org/jira/browse/HBASE-21322) | *Major* | **Add a scheduleServerCrashProcedure() API to HbckService**
+
+Adds scheduleServerCrashProcedure to the HbckService.
+
+
+---
+
+* [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-21075](https://issues.apache.org/jira/browse/HBASE-21075) | *Blocker* | **Confirm that we can (rolling) upgrade from 2.0.x and 2.1.x to 2.2.x after HBASE-20881**
+
+hbase-2.2.x uses a new Procedure form assiging/unassigning/moving Regions; it does not process hbase-2.1.x and earlier Unassign/Assign Procedure types. Upgrade requires that we first drain the Master Procedure Store of old style Procedures before starting the new 2.2.x Master. The patch here facilitates the draining process.
+
+On your running hbase-2.1.1+ (or 2.0.3+ cluster), when upgrading:
+
+1. Shutdown both active and standby masters (Your cluster will continue to server reads and writes without interruption).
+2. Set the property hbase.procedure.upgrade-to-2-2 to true in hbase-site.xml for the Master, and start only one Master, still using the 2.1.1+ (or 2.0.3+) binaries.
+3. Wait until the Master quits. Confirm that there is a 'READY TO ROLLING UPGRADE' message in the master log as the cause of the shutdown. The Procedure Store is now empty.
+4. Start new Masters with the new 2.2.0+ code.
+
+
+---
+
+* [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-21158](https://issues.apache.org/jira/browse/HBASE-21158) | *Critical* | **Empty qualifier cell should not be returned if it does not match QualifierFilter**
+
+<!-- markdown -->
+# HBASE 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+
+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-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-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 2.0.2 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+---
+
+* [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 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+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-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-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-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-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-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-20691](https://issues.apache.org/jira/browse/HBASE-20691) | *Blocker* | **Storage policy should allow deferring to HDFS**
+
+After HBASE-20691 we have changed the default setting of hbase.wal.storage.policy from "HOT" back to "NONE" which means we defer the policy to HDFS. This fixes the problem of release 2.0.0 that the storage policy of WAL directory will defer to HDFS and may not be "HOT" even if you explicitly set hbase.wal.storage.policy to "HOT"
+
+
+---
+
+* [HBASE-20839](https://issues.apache.org/jira/browse/HBASE-20839) | *Blocker* | **Fallback to FSHLog if we can not instantiated AsyncFSWAL when user does not specify AsyncFSWAL explicitly**
+
+As we hack into the internal of DFSClient when implementing AsyncFSWAL to get better performance, a patch release of hadoop can make it broken.
+
+So now, if user does not specify a wal provider, then we will first try to use 'asyncfs', i.e, the AsyncFSWALProvider. If we fail due to some compatible issues, we will fallback to 'filesystem', i.e, FSHLog.
+
+
+---
+
+* [HBASE-20244](https://issues.apache.org/jira/browse/HBASE-20244) | *Blocker* | **NoSuchMethodException when retrieving private method decryptEncryptedDataEncryptionKey from DFSClient**
+
+HDFS-12574 made an incompatible change to HdfsKMSUtil with different method signature.
+This issue uses reflection to try known method signatures in order to work with hadoop releases with and without HDFS-12574
+
+
+---
+
+* [HBASE-20642](https://issues.apache.org/jira/browse/HBASE-20642) | *Major* | **IntegrationTestDDLMasterFailover throws 'InvalidFamilyOperationException**
+
+This changes client-side nonce generation to use the same nonce for re-submissions of client RPC DDL operations.
+
+
+---
+
+* [HBASE-20745](https://issues.apache.org/jira/browse/HBASE-20745) | *Major* | **Log when master proc wal rolls**
+
+Log Master WAL Proc at INFO level so can tell where we transition; will help debugging/figuring accounting. Also change DEFAULT\_RIT\_CHORE\_INTERVAL\_MSEC from 5 to 60 seconds; makes it so we emit STUCK RIT notice once a minute only rather than 12 times a minute (latter was causing us to quickly roll-away the logging around problem 'events').
+
+
+---
+
+* [HBASE-20681](https://issues.apache.org/jira/browse/HBASE-20681) | *Major* | **IntegrationTestDriver fails after HADOOP-15406 due to missing hamcrest-core**
+
+<!-- markdown -->
+# HBASE 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+
+Users of our integration tests on Hadoop 3 can now add all needed dependencies by pointing at jars included in our binary convenience artifact.
+
+Prior to this fix, downstream users on Hadoop 3 would need to get a copy of the Hamcrest v1.3 jar from elsewhere.
+
+
+
+# HBASE 2.0.1 Release Notes
+
+---
+
+* [HBASE-20590](https://issues.apache.org/jira/browse/HBASE-20590) | *Critical* | **REST Java client is not able to negotiate with the server in the secure mode**
+
+Adds a negotiation logic between a secure java REST client and server. After this jira the Java REST client will start responding to the Negotiate challenge sent by the server. Adds RESTDemoClient which can be used to verify whether the secure Java REST client works against secure REST server or not.
+
+
+---
+
+* [HBASE-20634](https://issues.apache.org/jira/browse/HBASE-20634) | *Critical* | **Reopen region while server crash can cause the procedure to be stuck**
+
+A second attempt at fixing HBASE-20173. Fixes unfinished keeping of server state inside AM (ONLINE=\>SPLITTING=\>OFFLINE=\>null). Concurrent unassigns look at server state to figure if they should wait on SCP to wake them up or not.
+
+
+---
+
+* [HBASE-20592](https://issues.apache.org/jira/browse/HBASE-20592) | *Minor* | **Create a tool to verify tables do not have prefix tree encoding**
+
+PreUpgradeValidator tool with DataBlockEncoding validator was added to verify cluster is upgradable to HBase 2.
+
+
+---
+
+* [HBASE-20661](https://issues.apache.org/jira/browse/HBASE-20661) | *Major* | **Move version from 2.0.0 to 2.0.1-SNAPSHOT in branch-2.0**
+
+Move version from 2.0.0 to 2.0.1-SNAPSHOT in all poms.
+
+
+---
+
+* [HBASE-20544](https://issues.apache.org/jira/browse/HBASE-20544) | *Blocker* | **downstream HBaseTestingUtility fails with invalid port**
+
+<!-- markdown -->
+# HBASE 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+
+HBase now relies on an internal mechanism to determine when it is running a local hbase cluster meant for external interaction vs an encapsulated test. When created via the `HBaseTestingUtility`, ports for Master and RegionServer services and UIs will be set to random ports to allow for multiple parallel uses on a single machine. Normally when running a Standalone HBase Deployment (as described in the HBase Reference Guide) the ports will be picked according to the same defaults used in a full cluster set up. If you wish to instead use the random port assignment set `hbase.localcluster.assign.random.ports` to true.
+
+
+---
+
+* [HBASE-20004](https://issues.apache.org/jira/browse/HBASE-20004) | *Minor* | **Client is not able to execute REST queries in a secure cluster**
+
+Added 'hbase.rest.http.allow.options.method' configuration property to allow user to decide whether Rest Server HTTP should allow OPTIONS method or not. By default it is enabled in HBase 2.1.0+ versions and in other versions it is disabled.
+Similarly 'hbase.thrift.http.allow.options.method' is added HBase 1.5, 2.1.0 and 3.0.0 versions. It is disabled by default.
+
+
+---
+
+* [HBASE-20327](https://issues.apache.org/jira/browse/HBASE-20327) | *Minor* | **When qualifier is not specified, append and incr operation do not work (shell)**
+
+This change will enable users to perform append and increment operation with null qualifier via hbase-shell.
+
+
+---
+
+* [HBASE-18842](https://issues.apache.org/jira/browse/HBASE-18842) | *Minor* | **The hbase shell clone\_snaphost command returns bad error message**
+
+<!-- markdown -->
+# HBASE 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+
+When attempting to clone a snapshot but using a namespace that does not exist, the HBase shell will now correctly report the exception as caused by the passed namespace. Previously, the shell would report that the problem was an unknown namespace but it would claim the user provided table name was not found as a namespace. Both before and after this change the shell properly used the passed namespace to attempt to handle the request.
+
+
+
+
+# HBASE 2.0.0 Release Notes
+
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [HBASE-20464](https://issues.apache.org/jira/browse/HBASE-20464) | *Major* | **Disable IMC**
+
+Change the default so that on creation of new tables, In-Memory Compaction BASIC is NOT enabled.
+
+This change is in branch-2.0 only, not in branch-2.
+
+
+---
+
+* [HBASE-20276](https://issues.apache.org/jira/browse/HBASE-20276) | *Blocker* | **[shell] Revert shell REPL change and document**
+
+<!-- markdown -->
+# HBASE 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+The HBase shell now behaves as it did prior to the changes that started in HBASE-15965. Namely, some shell commands return values that may be further manipulated within the shell's IRB session.
+
+The command line option `--return-values` is no longer acted on by the shell since it now always behaves as it did when passed this parameter. Passing the option results in a harmless warning about this change.
+
+Users who wish to maintain the behavior seen in the 1.4.0-1.4.2 releases of the HBase shell should refer to the section _irbrc_ in the reference guide for how to configure their IRB session to avoid echoing expression results to the console.
+
+
+---
+
+* [HBASE-18792](https://issues.apache.org/jira/browse/HBASE-18792) | *Blocker* | **hbase-2 needs to defend against hbck operations**
+
+As of HBase version 2.0, the hbck tool is significantly changed. In general, all Read-Only options are supported and can be be used safely. Most -fix/ -repair options are NOT supported. Please see usage below for details on which options are not supported:
+
+
+Usage: fsck [opts] {only tables}
+ where [opts] are:
+ -help Display help options (this)
+ -details Display full report of all regions.
+ -timelag \<timeInSeconds\> Process only regions that have not experienced any metadata updates in the last \<timeInSeconds\> seconds.
+ -sleepBeforeRerun \<timeInSeconds\> Sleep this many seconds before checking if the fix worked if run with -fix
+ -summary Print only summary of the tables and status.
+ -metaonly Only check the state of the hbase:meta table.
+ -sidelineDir \<hdfs://\> HDFS path to backup existing meta.
+ -boundaries Verify that regions boundaries are the same between META and store files.
+ -exclusive Abort if another hbck is exclusive or fixing.
+
+ Datafile Repair options: (expert features, use with caution!)
+ -checkCorruptHFiles Check all Hfiles by opening them to make sure they are valid
+ -sidelineCorruptHFiles Quarantine corrupted HFiles. implies -checkCorruptHFiles
+
+ Replication options
+ -fixReplication Deletes replication queues for removed peers
+
+ Metadata Repair options supported as of version 2.0: (expert features, use with caution!)
+ -fixVersionFile Try to fix missing hbase.version file in hdfs.
+ -fixReferenceFiles Try to offline lingering reference store files
+ -fixHFileLinks Try to offline lingering HFileLinks
+ -noHdfsChecking Don't load/check region info from HDFS. Assumes hbase:meta region info is good. Won't check/fix any HDFS issue, e.g. hole, orphan, or overlap
+ -ignorePreCheckPermission ignore filesystem permission pre-check
+
+NOTE: Following options are NOT supported as of HBase version 2.0+.
+
+ UNSUPPORTED Metadata Repair options: (expert features, use with caution!)
+ -fix Try to fix region assignments. This is for backwards compatiblity
+ -fixAssignments Try to fix region assignments. Replaces the old -fix
+ -fixMeta Try to fix meta problems. This assumes HDFS region info is good.
+ -fixHdfsHoles Try to fix region holes in hdfs.
+ -fixHdfsOrphans Try to fix region dirs with no .regioninfo file in hdfs
+ -fixTableOrphans Try to fix table dirs with no .tableinfo file in hdfs (online mode only)
+ -fixHdfsOverlaps Try to fix region overlaps in hdfs.
+ -maxMerge \<n\> When fixing region overlaps, allow at most \<n\> regions to merge. (n=5 by default)
+ -sidelineBigOverlaps When fixing region overlaps, allow to sideline big overlaps
+ -maxOverlapsToSideline \<n\> When fixing region overlaps, allow at most \<n\> regions to sideline per group. (n=2 by default)
+ -fixSplitParents Try to force offline split parents to be online.
+ -removeParents Try to offline and sideline lingering parents and keep daughter regions.
+ -fixEmptyMetaCells Try to fix hbase:meta entries not referencing any region (empty REGIONINFO\_QUALIFIER rows)
+
+ UNSUPPORTED Metadata Repair shortcuts
+ -repair Shortcut for -fixAssignments -fixMeta -fixHdfsHoles -fixHdfsOrphans -fixHdfsOverlaps -fixVersionFile -sidelineBigOverlaps -fixReferenceFiles-fixHFileLinks
+ -repairHoles Shortcut for -fixAssignments -fixMeta -fixHdfsHoles
+
+
+---
+
+* [HBASE-19994](https://issues.apache.org/jira/browse/HBASE-19994) | *Major* | **Create a new class for RPC throttling exception, make it retryable.**
+
+A new RpcThrottlingException deprecates ThrottlingException. The new RpcThrottlingException is a retryable Exception that clients will retry when Rpc throttling quota is exceeded. The deprecated ThrottlingException is a nonretryable Exception.
+
+
+---
+
+* [HBASE-20224](https://issues.apache.org/jira/browse/HBASE-20224) | *Blocker* | **Web UI is broken in standalone mode**
+
+Standalone webui was broken inadvertently by HBASE-20027.
+
+
+---
+
+* [HBASE-18784](https://issues.apache.org/jira/browse/HBASE-18784) | *Major* | **Use of filesystem that requires hflush / hsync / append / etc should query outputstream capabilities**
+
+<!-- markdown -->
+# HBASE 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+
+If HBase is run on top of Apache Hadoop libraries that support the needed APIs it will verify that underlying Filesystem implementations provide the needed durability mechanisms to safely operate. The needed APIs *should* be present in Hadoop 3 release and Hadoop 2 releases starting in the Hadoop 2.9 series. If the APIs are not available, HBase behaves as it has in previous releases (that is, it moves forward assuming such a check would pass).
+
+Where this check fails, it is unsafe to rely on HBase in a production setting. In the event of process or node failure, the HBase RegionServer process may fail to have access to all the data it previously wrote to its write ahead log, resulting in data loss. In the event of process or node failure, the HBase master process may lose all or part of the write ahead log that it relies on for cluster management operations, leaving the cluster in an inconsistent state that we aren't sure it could recover from.
+
+Notably, the LocalFileSystem implementation provided by Hadoop reports (accurately) via these new APIs that it can not provide the durability HBase needs to operate. As such, the current instructions for single-node HBase operation have been updated both with a) how to bypass this safety check and b) a strong warning about the dire consequences of doing so outside of a dev/test environment.
+
+
+---
+
+* [HBASE-20219](https://issues.apache.org/jira/browse/HBASE-20219) | *Critical* | **An error occurs when scanning with reversed=true and loadColumnFamiliesOnDemand=true**
+
+Throws DoNotRetryIOException when you ask for a reverse scan loading adjacent column families on demand. Previous it threw IllegalStateException
+
+
+---
+
+* [HBASE-20358](https://issues.apache.org/jira/browse/HBASE-20358) | *Minor* | **Fix bin/hbase thrift usage text**
+
+Cleanup usage message and command-line processing (no functional change).
+
+
+---
+
+* [HBASE-20182](https://issues.apache.org/jira/browse/HBASE-20182) | *Blocker* | **Can not locate region after split and merge**
+
+Now if we hit a split parent when locating a region, we will skip to the next row and try again until the region does not contain our row. So there will be no RegionOfflineException for a split parent any more, instead, if the split children have not been onlined yet, i.e, we finally arrive at a region which does not contain our row, an IOException will be thrown.
+
+
+---
+
+* [HBASE-20149](https://issues.apache.org/jira/browse/HBASE-20149) | *Critical* | **Purge dev javadoc from bin tarball (or make a separate tarball of javadoc)**
+
+We no longer include dev or dev test javadocs in our binary bundle. We still build them; they are just not included because they were half the size of the resultant tarball.
+
+Here is our story on javadoc as of this commit:
+
+ \* apidocs - user facing main api javadocs. currently for a release line, published on website and linked from menu. included in the bin tarball
+ \* devapidocs - hbase internal javadocs. currently for a release line, published on the website but not linked from the menu. no longer included in the bin tarball.
+ \* testapidocs - user facing test scope api javadocs. currently for a release line, not published. included in the bin tarball.
+ \* testdevapidocs - hbase internal test scope javadocs. currently for a release line, not published. no longer included in the bin tarball
+
+
+---
+
+* [HBASE-18828](https://issues.apache.org/jira/browse/HBASE-18828) | *Blocker* | **[2.0] Generate CHANGES.txt**
+
+Moves us over to yetus releasedocmaker tooling generating CHANGES. CHANGES is not markdown (CHANGES.md) as opposed to CHANGES.txt. We've also added a new RELEASENOTES.md that lists JIRA release notes (courtesy of releasedocmaker).
+
+CHANGES/RELEASENOTES are current as of now. Will need a 'freshening' when we cut the RC.
+
+
+---
+
+* [HBASE-14175](https://issues.apache.org/jira/browse/HBASE-14175) | *Critical* | **Adopt releasedocmaker for better generated release notes**
+
+We will use yetus releasedocmaker to make our changes doc from here on out. A CHANGELOG.md will replace our current CHANGES.txt. Adjacent, we'll keep up a RELEASENOTES.md doc courtesy of releasedocmaker.
+
+Over in HBASE-18828 is where we are working through steps for the RM integrating this new tooling.
+
+
+---
+
+* [HBASE-16499](https://issues.apache.org/jira/browse/HBASE-16499) | *Critical* | **slow replication for small HBase clusters**
+
+Changed the default value for replication.source.ratio from 0.1 to 0.5. Which means now by default 50% of the total RegionServers in peer cluster(s) will participate in replication.
+
+
+---
+
+* [HBASE-16459](https://issues.apache.org/jira/browse/HBASE-16459) | *Trivial* | **Remove unused hbase shell --format option**
+
+<!-- markdown -->
+# HBASE 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+
+The HBase `shell` command no longer recognizes the option `--format`. Previously this option only recognized the default value of 'console'. The default value is now always used.
+
+
+---
+
+* [HBASE-20259](https://issues.apache.org/jira/browse/HBASE-20259) | *Critical* | **Doc configs for in-memory-compaction and add detail to in-memory-compaction logging**
+
+Disables in-memory compaction as default.
+
+Adds logging of in-memory compaction configuration on creation.
+
+Adds a chapter to the refguide on this new feature.
+
+
+---
+
+* [HBASE-20282](https://issues.apache.org/jira/browse/HBASE-20282) | *Major* | **Provide short name invocations for useful tools**
+
+\`hbase regionsplitter\` is a new short invocation for \`hbase org.apache.hadoop.hbase.util.RegionSplitter\`
+
+
+---
+
+* [HBASE-20314](https://issues.apache.org/jira/browse/HBASE-20314) | *Major* | **Precommit build for master branch fails because of surefire fork fails**
+
+Upgrade surefire plugin to 2.21.0.
+
+
+---
+
+* [HBASE-20130](https://issues.apache.org/jira/browse/HBASE-20130) | *Critical* | **Use defaults (16020 & 16030) as base ports when the RS is bound to localhost**
+
+<!-- markdown -->
+# HBASE 2.0.5 Release Notes
+
+These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.
+
+
+---
+
+* [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-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-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-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-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-18569](https://issues.apache.org/jira/browse/HBASE-18569) | *Major* | **Add prefetch support for async region locator**
+
+Add prefetch support for async region locator. The default value is 10. Set 'hbase.client.locate.prefetch.limit' in hbase-site.xml if you want to use another value for it.
+
+
+
+When region servers bind to localhost (mostly in pseudo distributed mode), default ports (16020 & 16030) are used as base ports. This will support up to 9 instances of region servers by default with `local-regionservers.sh` script. If additional instances are needed, see the reference guide on how to deploy with a different range using the environment variables `HBASE_RS_BASE_PORT` and `HBASE_RS_INFO_BASE_PORT`.
+
+
+---
+
+* [HBASE-20111](https://issues.apache.org/jira/browse/HBASE-20111) | *Critical* | **Able to split region explicitly even on shouldSplit return false from split policy**
+
+When a split is requested on a Region, the RegionServer hosting that Region will now consult the configured SplitPolicy for that table when determining if a split of that Region is allowed. When a split is disallowed (due to the Region not being OPEN or the SplitPolicy denying the request), the operation will \*not\* be implicitly retried as it has previously done. Users will need to guard against and explicitly retry region split requests which are denied by the system.
+
+
+---
+
+* [HBASE-20223](https://issues.apache.org/jira/browse/HBASE-20223) | *Blocker* | **Use hbase-thirdparty 2.1.0**
+
+Moves commons-cli and commons-collections4 into the HBase thirdparty shaded jar which means that these are no longer generally available for users on the classpath.
+
+
+---
+
+* [HBASE-19128](https://issues.apache.org/jira/browse/HBASE-19128) | *Major* | **Purge Distributed Log Replay from codebase, configurations, text; mark the feature as unsupported, broken.**
+
+Removes Distributed Log Replay feature. Disable the feature before upgrading.
+
+
+---
+
+* [HBASE-19504](https://issues.apache.org/jira/browse/HBASE-19504) | *Major* | **Add TimeRange support into checkAndMutate**
+
+1) checkAndMutate accept a TimeRange to query the specified cell
+2) remove writeToWAL flag from Region#checkAndMutate since it is useless (this is a incompatible change)
+
+
+---
+
+* [HBASE-20237](https://issues.apache.org/jira/browse/HBASE-20237) | *Critical* | **Put back getClosestRowBefore and throw UnknownProtocolException instead... for asynchbase client**
+
+Throw UnknownProtocolException if a client connects and tries to invoke the old getClosestRowOrBefore method. Pre-hbase-1.0.0 or asynchbase do this instead of using its replacement, the reverse Scan.
+
+getClosestRowOrBefore was implemented as a flag on Get. Before this patch though the flag was set, hbase2 were ignoring it. This made it look like a pre-1.0.0 client was 'working' but then it'd fail finding the appropriate Region for a client-specified row doing lookups into hbase:meta.
+
+
+---
+
+* [HBASE-20247](https://issues.apache.org/jira/browse/HBASE-20247) | *Major* | **Set version as 2.0.0 in branch-2.0 in prep for first RC**
+
+Set version as 2.0.0 on branch-2.0.
+
+
+---
+
+* [HBASE-20090](https://issues.apache.org/jira/browse/HBASE-20090) | *Major* | **Properly handle Preconditions check failure in MemStoreFlusher$FlushHandler.run**
+
+When there is concurrent region split, MemStoreFlusher may not find flushable region if the only candidate region left hasn't received writes (resulting in 0 data size).
+After this JIRA, such scenario wouldn't trigger Precondition assertion (replaced by an if statement to see whether there is any flushable region).
+If there is no flushable region, a DEBUG log would appear in region server log, saying "Above memory mark but there is no flushable region".
+
+
+---
+
+* [HBASE-19552](https://issues.apache.org/jira/browse/HBASE-19552) | *Major* | **update hbase to use new thirdparty libs**
+
+hbase-thirdparty libs have moved to o.a.h.thirdparty offset. Netty shading system property is no longer necessary.
+
+
+---
+
+* [HBASE-20119](https://issues.apache.org/jira/browse/HBASE-20119) | *Minor* | **Introduce a pojo class to carry coprocessor information in order to make TableDescriptorBuilder accept multiple cp at once**
+
+1) Make all methods in TableDescriptorBuilder be setter pattern.
+addCoprocessor -\> setCoprocessor
+addColumnFamily -\> setColumnFamily
+(addCoprocessor and addColumnFamily are still in branch-2 but they are marked as deprecated)
+2) add CoprocessorDescriptor to carry cp information
+3) add CoprocessorDescriptorBuilder to build CoprocessorDescriptor
+4) TD disallow user to set negative priority to coprocessor since parsing the negative value will cause a exception
+
+
+---
+
+* [HBASE-17165](https://issues.apache.org/jira/browse/HBASE-17165) | *Critical* | **Add retry to LoadIncrementalHFiles tool**
+
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