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Posted to commits@hbase.apache.org by st...@apache.org on 2013/04/02 20:06:21 UTC
svn commit: r1463652 [4/21] - in /hbase/hbase.apache.org/trunk: ./ book/
case_studies/ community/ configuration/ css/ developer/ external_apis/
getting_started/ hbase-assembly/ hbase-assembly/book/ hbase-assembly/xref/
images/ ops_mgt/ performance/ pre...
Modified: hbase/hbase.apache.org/trunk/book/book.html
URL: http://svn.apache.org/viewvc/hbase/hbase.apache.org/trunk/book/book.html?rev=1463652&r1=1463651&r2=1463652&view=diff
==============================================================================
--- hbase/hbase.apache.org/trunk/book/book.html (original)
+++ hbase/hbase.apache.org/trunk/book/book.html Tue Apr 2 18:06:19 2013
@@ -10,15 +10,15 @@
</h2></div><div><p class="copyright">Copyright © 2012 Apache Software Foundation.
All Rights Reserved. Apache Hadoop, Hadoop, MapReduce, HDFS, Zookeeper, HBase, and the HBase project logo are trademarks of the Apache Software Foundation.
</p></div><div><div class="revhistory"><table border="1" width="100%" summary="Revision history"><tr><th align="left" valign="top" colspan="2"><b>Revision History</b></th></tr><tr><td align="left">Revision
- 0.97-SNAPSHOT
+ 0.97.0-SNAPSHOT
</td><td align="left">
- 2013-03-29T16:44
+ 2013-04-02T11:01
</td></tr></table></div></div><div><div class="abstract" title="Abstract"><p class="title"><b>Abstract</b></p><p>This is the official reference guide of
<a class="link" href="http://www.hbase.org" target="_top">Apache HBase (TM)</a>,
a distributed, versioned, column-oriented database built on top of
<a class="link" href="http://hadoop.apache.org/" target="_top">Apache Hadoop</a> and
<a class="link" href="http://zookeeper.apache.org/" target="_top">Apache ZooKeeper</a>.
- </p></div></div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="preface"><a href="preface.html">Preface</a></span></dt><dt><span class="chapter"><a href="getting_started.html">1. Getting Started</a></span></dt><dd><dl><dt><span class="section"><a href="getting_started.html#d2279e77">1.1. Introduction</a></span></dt><dt><span class="section"><a href="quickstart.html">1.2. Quick Start</a></span></dt></dl></dd><dt><span class="chapter"><a href="configuration.html">2. Apache HBase (TM) Configuration</a></span></dt><dd><dl><dt><span class="section"><a href="configuration.html#basic.prerequisites">2.1. Basic Prerequisites</a></span></dt><dt><span class="section"><a href="standalone_dist.html">2.2. HBase run modes: Standalone and Distributed</a></span></dt><dt><span class="section"><a href="config.files.html">2.3. Configuration Files</a></span></dt><dt><span class="section"><a href="example_config.html">2.4. Example Configurations</a></spa
n></dt><dt><span class="section"><a href="important_configurations.html">2.5. The Important Configurations</a></span></dt></dl></dd><dt><span class="chapter"><a href="upgrading.html">3. Upgrading</a></span></dt><dd><dl><dt><span class="section"><a href="upgrading.html#upgrade0.96">3.1. Upgrading from 0.94.x to 0.96.x</a></span></dt><dt><span class="section"><a href="upgrade0.94.html">3.2. Upgrading from 0.92.x to 0.94.x</a></span></dt><dt><span class="section"><a href="upgrade0.92.html">3.3. Upgrading from 0.90.x to 0.92.x</a></span></dt><dt><span class="section"><a href="upgrade0.90.html">3.4. Upgrading to HBase 0.90.x from 0.20.x or 0.89.x</a></span></dt></dl></dd><dt><span class="chapter"><a href="shell.html">4. The Apache HBase Shell</a></span></dt><dd><dl><dt><span class="section"><a href="shell.html#scripting">4.1. Scripting</a></span></dt><dt><span class="section"><a href="shell_tricks.html">4.2. Shell Tricks</a></span></dt></dl></dd><dt><span class="chapter"><a href=
"datamodel.html">5. Data Model</a></span></dt><dd><dl><dt><span class="section"><a href="datamodel.html#conceptual.view">5.1. Conceptual View</a></span></dt><dt><span class="section"><a href="physical.view.html">5.2. Physical View</a></span></dt><dt><span class="section"><a href="table.html">5.3. Table</a></span></dt><dt><span class="section"><a href="row.html">5.4. Row</a></span></dt><dt><span class="section"><a href="columnfamily.html">5.5. Column Family</a></span></dt><dt><span class="section"><a href="cells.html">5.6. Cells</a></span></dt><dt><span class="section"><a href="data_model_operations.html">5.7. Data Model Operations</a></span></dt><dt><span class="section"><a href="versions.html">5.8. Versions</a></span></dt><dt><span class="section"><a href="dm.sort.html">5.9. Sort Order</a></span></dt><dt><span class="section"><a href="dm.column.metadata.html">5.10. Column Metadata</a></span></dt><dt><span class="section"><a href="joins.html">5.11. Joins</a></span></dt><dt><
span class="section"><a href="acid.html">5.12. ACID</a></span></dt></dl></dd><dt><span class="chapter"><a href="schema.html">6. HBase and Schema Design</a></span></dt><dd><dl><dt><span class="section"><a href="schema.html#schema.creation">6.1.
+ </p></div></div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="preface"><a href="preface.html">Preface</a></span></dt><dt><span class="chapter"><a href="getting_started.html">1. Getting Started</a></span></dt><dd><dl><dt><span class="section"><a href="getting_started.html#d2475e77">1.1. Introduction</a></span></dt><dt><span class="section"><a href="quickstart.html">1.2. Quick Start</a></span></dt></dl></dd><dt><span class="chapter"><a href="configuration.html">2. Apache HBase (TM) Configuration</a></span></dt><dd><dl><dt><span class="section"><a href="configuration.html#basic.prerequisites">2.1. Basic Prerequisites</a></span></dt><dt><span class="section"><a href="standalone_dist.html">2.2. HBase run modes: Standalone and Distributed</a></span></dt><dt><span class="section"><a href="config.files.html">2.3. Configuration Files</a></span></dt><dt><span class="section"><a href="example_config.html">2.4. Example Configurations</a></spa
n></dt><dt><span class="section"><a href="important_configurations.html">2.5. The Important Configurations</a></span></dt></dl></dd><dt><span class="chapter"><a href="upgrading.html">3. Upgrading</a></span></dt><dd><dl><dt><span class="section"><a href="upgrading.html#hbase.versioning">3.1. HBase version numbers</a></span></dt><dt><span class="section"><a href="upgrade0.96.html">3.2. Upgrading from 0.94.x to 0.96.x</a></span></dt><dt><span class="section"><a href="upgrade0.94.html">3.3. Upgrading from 0.92.x to 0.94.x</a></span></dt><dt><span class="section"><a href="upgrade0.92.html">3.4. Upgrading from 0.90.x to 0.92.x</a></span></dt><dt><span class="section"><a href="upgrade0.90.html">3.5. Upgrading to HBase 0.90.x from 0.20.x or 0.89.x</a></span></dt></dl></dd><dt><span class="chapter"><a href="shell.html">4. The Apache HBase Shell</a></span></dt><dd><dl><dt><span class="section"><a href="shell.html#scripting">4.1. Scripting</a></span></dt><dt><span class="section"><a hr
ef="shell_tricks.html">4.2. Shell Tricks</a></span></dt></dl></dd><dt><span class="chapter"><a href="datamodel.html">5. Data Model</a></span></dt><dd><dl><dt><span class="section"><a href="datamodel.html#conceptual.view">5.1. Conceptual View</a></span></dt><dt><span class="section"><a href="physical.view.html">5.2. Physical View</a></span></dt><dt><span class="section"><a href="table.html">5.3. Table</a></span></dt><dt><span class="section"><a href="row.html">5.4. Row</a></span></dt><dt><span class="section"><a href="columnfamily.html">5.5. Column Family</a></span></dt><dt><span class="section"><a href="cells.html">5.6. Cells</a></span></dt><dt><span class="section"><a href="data_model_operations.html">5.7. Data Model Operations</a></span></dt><dt><span class="section"><a href="versions.html">5.8. Versions</a></span></dt><dt><span class="section"><a href="dm.sort.html">5.9. Sort Order</a></span></dt><dt><span class="section"><a href="dm.column.metadata.html">5.10. Column Met
adata</a></span></dt><dt><span class="section"><a href="joins.html">5.11. Joins</a></span></dt><dt><span class="section"><a href="acid.html">5.12. ACID</a></span></dt></dl></dd><dt><span class="chapter"><a href="schema.html">6. HBase and Schema Design</a></span></dt><dd><dl><dt><span class="section"><a href="schema.html#schema.creation">6.1.
Schema Creation
</a></span></dt><dt><span class="section"><a href="number.of.cfs.html">6.2.
On the number of column families
@@ -30,7 +30,7 @@
Keeping Deleted Cells
</a></span></dt><dt><span class="section"><a href="secondary.indexes.html">6.9.
Secondary Indexes and Alternate Query Paths
- </a></span></dt><dt><span class="section"><a href="schema.smackdown.html">6.10. Schema Design Smackdown</a></span></dt><dt><span class="section"><a href="schema.ops.html">6.11. Operational and Performance Configuration Options</a></span></dt><dt><span class="section"><a href="constraints.html">6.12. Constraints</a></span></dt></dl></dd><dt><span class="chapter"><a href="mapreduce.html">7. HBase and MapReduce</a></span></dt><dd><dl><dt><span class="section"><a href="mapreduce.html#splitter">7.1. Map-Task Spitting</a></span></dt><dt><span class="section"><a href="mapreduce.example.html">7.2. HBase MapReduce Examples</a></span></dt><dt><span class="section"><a href="mapreduce.htable.access.html">7.3. Accessing Other HBase Tables in a MapReduce Job</a></span></dt><dt><span class="section"><a href="mapreduce.specex.html">7.4. Speculative Execution</a></span></dt></dl></dd><dt><span class="chapter"><a href="security.html">8. Secure Apache HBase (TM)</a></span></dt><dd><dl><dt><s
pan class="section"><a href="security.html#hbase.secure.configuration">8.1. Secure Client Access to Apache HBase</a></span></dt><dt><span class="section"><a href="hbase.accesscontrol.configuration.html">8.2. Access Control</a></span></dt><dt><span class="section"><a href="hbase.secure.bulkload.html">8.3. Secure Bulk Load</a></span></dt></dl></dd><dt><span class="chapter"><a href="architecture.html">9. Architecture</a></span></dt><dd><dl><dt><span class="section"><a href="architecture.html#arch.overview">9.1. Overview</a></span></dt><dt><span class="section"><a href="arch.catalog.html">9.2. Catalog Tables</a></span></dt><dt><span class="section"><a href="client.html">9.3. Client</a></span></dt><dt><span class="section"><a href="client.filter.html">9.4. Client Request Filters</a></span></dt><dt><span class="section"><a href="master.html">9.5. Master</a></span></dt><dt><span class="section"><a href="regionserver.arch.html">9.6. RegionServer</a></span></dt><dt><span class="secti
on"><a href="regions.arch.html">9.7. Regions</a></span></dt><dt><span class="section"><a href="arch.bulk.load.html">9.8. Bulk Loading</a></span></dt><dt><span class="section"><a href="arch.hdfs.html">9.9. HDFS</a></span></dt></dl></dd><dt><span class="chapter"><a href="external_apis.html">10. Apache HBase (TM) External APIs</a></span></dt><dd><dl><dt><span class="section"><a href="external_apis.html#nonjava.jvm">10.1. Non-Java Languages Talking to the JVM</a></span></dt><dt><span class="section"><a href="rest.html">10.2. REST</a></span></dt><dt><span class="section"><a href="thrift.html">10.3. Thrift</a></span></dt><dt><span class="section"><a href="c.html">10.4. C/C++ Apache HBase Client</a></span></dt></dl></dd><dt><span class="chapter"><a href="performance.html">11. Apache HBase (TM) Performance Tuning</a></span></dt><dd><dl><dt><span class="section"><a href="performance.html#perf.os">11.1. Operating System</a></span></dt><dt><span class="section"><a href="perf.network.ht
ml">11.2. Network</a></span></dt><dt><span class="section"><a href="jvm.html">11.3. Java</a></span></dt><dt><span class="section"><a href="perf.configurations.html">11.4. HBase Configurations</a></span></dt><dt><span class="section"><a href="perf.zookeeper.html">11.5. ZooKeeper</a></span></dt><dt><span class="section"><a href="perf.schema.html">11.6. Schema Design</a></span></dt><dt><span class="section"><a href="perf.general.html">11.7. HBase General Patterns</a></span></dt><dt><span class="section"><a href="perf.writing.html">11.8. Writing to HBase</a></span></dt><dt><span class="section"><a href="perf.reading.html">11.9. Reading from HBase</a></span></dt><dt><span class="section"><a href="perf.deleting.html">11.10. Deleting from HBase</a></span></dt><dt><span class="section"><a href="perf.hdfs.html">11.11. HDFS</a></span></dt><dt><span class="section"><a href="perf.ec2.html">11.12. Amazon EC2</a></span></dt><dt><span class="section"><a href="perf.casestudy.html">11.13. Ca
se Studies</a></span></dt></dl></dd><dt><span class="chapter"><a href="trouble.html">12. Troubleshooting and Debugging Apache HBase (TM)</a></span></dt><dd><dl><dt><span class="section"><a href="trouble.html#trouble.general">12.1. General Guidelines</a></span></dt><dt><span class="section"><a href="trouble.log.html">12.2. Logs</a></span></dt><dt><span class="section"><a href="trouble.resources.html">12.3. Resources</a></span></dt><dt><span class="section"><a href="trouble.tools.html">12.4. Tools</a></span></dt><dt><span class="section"><a href="trouble.client.html">12.5. Client</a></span></dt><dt><span class="section"><a href="trouble.mapreduce.html">12.6. MapReduce</a></span></dt><dt><span class="section"><a href="trouble.namenode.html">12.7. NameNode</a></span></dt><dt><span class="section"><a href="trouble.network.html">12.8. Network</a></span></dt><dt><span class="section"><a href="trouble.rs.html">12.9. RegionServer</a></span></dt><dt><span class="section"><a href="trou
ble.master.html">12.10. Master</a></span></dt><dt><span class="section"><a href="trouble.zookeeper.html">12.11. ZooKeeper</a></span></dt><dt><span class="section"><a href="trouble.ec2.html">12.12. Amazon EC2</a></span></dt><dt><span class="section"><a href="trouble.versions.html">12.13. HBase and Hadoop version issues</a></span></dt><dt><span class="section"><a href="trouble.casestudy.html">12.14. Case Studies</a></span></dt></dl></dd><dt><span class="chapter"><a href="casestudies.html">13. Apache HBase (TM) Case Studies</a></span></dt><dd><dl><dt><span class="section"><a href="casestudies.html#casestudies.overview">13.1. Overview</a></span></dt><dt><span class="section"><a href="casestudies.schema.html">13.2. Schema Design</a></span></dt><dt><span class="section"><a href="casestudies.perftroub.html">13.3. Performance/Troubleshooting</a></span></dt></dl></dd><dt><span class="chapter"><a href="ops_mgt.html">14. Apache HBase (TM) Operational Management</a></span></dt><dd><dl><
dt><span class="section"><a href="ops_mgt.html#tools">14.1. HBase Tools and Utilities</a></span></dt><dt><span class="section"><a href="ops.regionmgt.html">14.2. Region Management</a></span></dt><dt><span class="section"><a href="node.management.html">14.3. Node Management</a></span></dt><dt><span class="section"><a href="hbase_metrics.html">14.4. HBase Metrics</a></span></dt><dt><span class="section"><a href="ops.monitoring.html">14.5. HBase Monitoring</a></span></dt><dt><span class="section"><a href="cluster_replication.html">14.6. Cluster Replication</a></span></dt><dt><span class="section"><a href="ops.backup.html">14.7. HBase Backup</a></span></dt><dt><span class="section"><a href="ops.capacity.html">14.8. Capacity Planning</a></span></dt></dl></dd><dt><span class="chapter"><a href="developer.html">15. Building and Developing Apache HBase (TM)</a></span></dt><dd><dl><dt><span class="section"><a href="developer.html#repos">15.1. Apache HBase Repositories</a></span></dt><
dt><span class="section"><a href="ides.html">15.2. IDEs</a></span></dt><dt><span class="section"><a href="build.html">15.3. Building Apache HBase</a></span></dt><dt><span class="section"><a href="mvn_repo.html">15.4. Adding an Apache HBase release to Apache's Maven Repository</a></span></dt><dt><span class="section"><a href="documentation.html">15.5. Generating the HBase Reference Guide</a></span></dt><dt><span class="section"><a href="hbase.org.html">15.6. Updating hbase.apache.org</a></span></dt><dt><span class="section"><a href="hbase.tests.html">15.7. Tests</a></span></dt><dt><span class="section"><a href="maven.build.commands.html">15.8. Maven Build Commands</a></span></dt><dt><span class="section"><a href="getting.involved.html">15.9. Getting Involved</a></span></dt><dt><span class="section"><a href="developing.html">15.10. Developing</a></span></dt><dt><span class="section"><a href="submitting.patches.html">15.11. Submitting Patches</a></span></dt></dl></dd><dt><span
class="chapter"><a href="zookeeper.html">16. ZooKeeper</a></span></dt><dd><dl><dt><span class="section"><a href="zookeeper.html#d2279e11082">16.1. Using existing ZooKeeper ensemble</a></span></dt><dt><span class="section"><a href="zk.sasl.auth.html">16.2. SASL Authentication with ZooKeeper</a></span></dt></dl></dd><dt><span class="chapter"><a href="community.html">17. Community</a></span></dt><dd><dl><dt><span class="section"><a href="community.html#decisions">17.1. Decisions</a></span></dt><dt><span class="section"><a href="community.roles.html">17.2. Community Roles</a></span></dt></dl></dd><dt><span class="appendix"><a href="faq.html">A. FAQ</a></span></dt><dt><span class="appendix"><a href="hbck.in.depth.html">B. hbck In Depth</a></span></dt><dd><dl><dt><span class="section"><a href="hbck.in.depth.html#d2279e11709">B.1. Running hbck to identify inconsistencies</a></span></dt><dt><span class="section"><a href="apbs02.html">B.2. Inconsistencies</a></span></dt><dt><span cla
ss="section"><a href="apbs03.html">B.3. Localized repairs</a></span></dt><dt><span class="section"><a href="apbs04.html">B.4. Region Overlap Repairs</a></span></dt></dl></dd><dt><span class="appendix"><a href="compression.html">C. Compression In HBase</a></span></dt><dd><dl><dt><span class="section"><a href="compression.html#compression.test">C.1. CompressionTest Tool</a></span></dt><dt><span class="section"><a href="hbase.regionserver.codecs.html">C.2.
+ </a></span></dt><dt><span class="section"><a href="constraints.html">6.10. Constraints</a></span></dt><dt><span class="section"><a href="schema.casestudies.html">6.11. Schema Design Case Studies</a></span></dt><dt><span class="section"><a href="schema.ops.html">6.12. Operational and Performance Configuration Options</a></span></dt></dl></dd><dt><span class="chapter"><a href="mapreduce.html">7. HBase and MapReduce</a></span></dt><dd><dl><dt><span class="section"><a href="mapreduce.html#splitter">7.1. Map-Task Spitting</a></span></dt><dt><span class="section"><a href="mapreduce.example.html">7.2. HBase MapReduce Examples</a></span></dt><dt><span class="section"><a href="mapreduce.htable.access.html">7.3. Accessing Other HBase Tables in a MapReduce Job</a></span></dt><dt><span class="section"><a href="mapreduce.specex.html">7.4. Speculative Execution</a></span></dt></dl></dd><dt><span class="chapter"><a href="security.html">8. Secure Apache HBase (TM)</a></span></dt><dd><dl><
dt><span class="section"><a href="security.html#hbase.secure.configuration">8.1. Secure Client Access to Apache HBase</a></span></dt><dt><span class="section"><a href="hbase.accesscontrol.configuration.html">8.2. Access Control</a></span></dt><dt><span class="section"><a href="hbase.secure.bulkload.html">8.3. Secure Bulk Load</a></span></dt></dl></dd><dt><span class="chapter"><a href="architecture.html">9. Architecture</a></span></dt><dd><dl><dt><span class="section"><a href="architecture.html#arch.overview">9.1. Overview</a></span></dt><dt><span class="section"><a href="arch.catalog.html">9.2. Catalog Tables</a></span></dt><dt><span class="section"><a href="client.html">9.3. Client</a></span></dt><dt><span class="section"><a href="client.filter.html">9.4. Client Request Filters</a></span></dt><dt><span class="section"><a href="master.html">9.5. Master</a></span></dt><dt><span class="section"><a href="regionserver.arch.html">9.6. RegionServer</a></span></dt><dt><span class="
section"><a href="regions.arch.html">9.7. Regions</a></span></dt><dt><span class="section"><a href="arch.bulk.load.html">9.8. Bulk Loading</a></span></dt><dt><span class="section"><a href="arch.hdfs.html">9.9. HDFS</a></span></dt></dl></dd><dt><span class="chapter"><a href="external_apis.html">10. Apache HBase (TM) External APIs</a></span></dt><dd><dl><dt><span class="section"><a href="external_apis.html#nonjava.jvm">10.1. Non-Java Languages Talking to the JVM</a></span></dt><dt><span class="section"><a href="rest.html">10.2. REST</a></span></dt><dt><span class="section"><a href="thrift.html">10.3. Thrift</a></span></dt><dt><span class="section"><a href="c.html">10.4. C/C++ Apache HBase Client</a></span></dt></dl></dd><dt><span class="chapter"><a href="performance.html">11. Apache HBase (TM) Performance Tuning</a></span></dt><dd><dl><dt><span class="section"><a href="performance.html#perf.os">11.1. Operating System</a></span></dt><dt><span class="section"><a href="perf.netwo
rk.html">11.2. Network</a></span></dt><dt><span class="section"><a href="jvm.html">11.3. Java</a></span></dt><dt><span class="section"><a href="perf.configurations.html">11.4. HBase Configurations</a></span></dt><dt><span class="section"><a href="perf.zookeeper.html">11.5. ZooKeeper</a></span></dt><dt><span class="section"><a href="perf.schema.html">11.6. Schema Design</a></span></dt><dt><span class="section"><a href="perf.general.html">11.7. HBase General Patterns</a></span></dt><dt><span class="section"><a href="perf.writing.html">11.8. Writing to HBase</a></span></dt><dt><span class="section"><a href="perf.reading.html">11.9. Reading from HBase</a></span></dt><dt><span class="section"><a href="perf.deleting.html">11.10. Deleting from HBase</a></span></dt><dt><span class="section"><a href="perf.hdfs.html">11.11. HDFS</a></span></dt><dt><span class="section"><a href="perf.ec2.html">11.12. Amazon EC2</a></span></dt><dt><span class="section"><a href="perf.casestudy.html">11.1
3. Case Studies</a></span></dt></dl></dd><dt><span class="chapter"><a href="trouble.html">12. Troubleshooting and Debugging Apache HBase (TM)</a></span></dt><dd><dl><dt><span class="section"><a href="trouble.html#trouble.general">12.1. General Guidelines</a></span></dt><dt><span class="section"><a href="trouble.log.html">12.2. Logs</a></span></dt><dt><span class="section"><a href="trouble.resources.html">12.3. Resources</a></span></dt><dt><span class="section"><a href="trouble.tools.html">12.4. Tools</a></span></dt><dt><span class="section"><a href="trouble.client.html">12.5. Client</a></span></dt><dt><span class="section"><a href="trouble.mapreduce.html">12.6. MapReduce</a></span></dt><dt><span class="section"><a href="trouble.namenode.html">12.7. NameNode</a></span></dt><dt><span class="section"><a href="trouble.network.html">12.8. Network</a></span></dt><dt><span class="section"><a href="trouble.rs.html">12.9. RegionServer</a></span></dt><dt><span class="section"><a href=
"trouble.master.html">12.10. Master</a></span></dt><dt><span class="section"><a href="trouble.zookeeper.html">12.11. ZooKeeper</a></span></dt><dt><span class="section"><a href="trouble.ec2.html">12.12. Amazon EC2</a></span></dt><dt><span class="section"><a href="trouble.versions.html">12.13. HBase and Hadoop version issues</a></span></dt><dt><span class="section"><a href="trouble.casestudy.html">12.14. Case Studies</a></span></dt></dl></dd><dt><span class="chapter"><a href="casestudies.html">13. Apache HBase (TM) Case Studies</a></span></dt><dd><dl><dt><span class="section"><a href="casestudies.html#casestudies.overview">13.1. Overview</a></span></dt><dt><span class="section"><a href="casestudies.schema.html">13.2. Schema Design</a></span></dt><dt><span class="section"><a href="casestudies.perftroub.html">13.3. Performance/Troubleshooting</a></span></dt></dl></dd><dt><span class="chapter"><a href="ops_mgt.html">14. Apache HBase (TM) Operational Management</a></span></dt><dd>
<dl><dt><span class="section"><a href="ops_mgt.html#tools">14.1. HBase Tools and Utilities</a></span></dt><dt><span class="section"><a href="ops.regionmgt.html">14.2. Region Management</a></span></dt><dt><span class="section"><a href="node.management.html">14.3. Node Management</a></span></dt><dt><span class="section"><a href="hbase_metrics.html">14.4. HBase Metrics</a></span></dt><dt><span class="section"><a href="ops.monitoring.html">14.5. HBase Monitoring</a></span></dt><dt><span class="section"><a href="cluster_replication.html">14.6. Cluster Replication</a></span></dt><dt><span class="section"><a href="ops.backup.html">14.7. HBase Backup</a></span></dt><dt><span class="section"><a href="ops.capacity.html">14.8. Capacity Planning</a></span></dt></dl></dd><dt><span class="chapter"><a href="developer.html">15. Building and Developing Apache HBase (TM)</a></span></dt><dd><dl><dt><span class="section"><a href="developer.html#repos">15.1. Apache HBase Repositories</a></span><
/dt><dt><span class="section"><a href="ides.html">15.2. IDEs</a></span></dt><dt><span class="section"><a href="build.html">15.3. Building Apache HBase</a></span></dt><dt><span class="section"><a href="mvn_repo.html">15.4. Adding an Apache HBase release to Apache's Maven Repository</a></span></dt><dt><span class="section"><a href="documentation.html">15.5. Generating the HBase Reference Guide</a></span></dt><dt><span class="section"><a href="hbase.org.html">15.6. Updating hbase.apache.org</a></span></dt><dt><span class="section"><a href="hbase.tests.html">15.7. Tests</a></span></dt><dt><span class="section"><a href="maven.build.commands.html">15.8. Maven Build Commands</a></span></dt><dt><span class="section"><a href="getting.involved.html">15.9. Getting Involved</a></span></dt><dt><span class="section"><a href="developing.html">15.10. Developing</a></span></dt><dt><span class="section"><a href="submitting.patches.html">15.11. Submitting Patches</a></span></dt></dl></dd><dt><
span class="chapter"><a href="zookeeper.html">16. ZooKeeper</a></span></dt><dd><dl><dt><span class="section"><a href="zookeeper.html#d2475e11337">16.1. Using existing ZooKeeper ensemble</a></span></dt><dt><span class="section"><a href="zk.sasl.auth.html">16.2. SASL Authentication with ZooKeeper</a></span></dt></dl></dd><dt><span class="chapter"><a href="community.html">17. Community</a></span></dt><dd><dl><dt><span class="section"><a href="community.html#decisions">17.1. Decisions</a></span></dt><dt><span class="section"><a href="community.roles.html">17.2. Community Roles</a></span></dt></dl></dd><dt><span class="appendix"><a href="faq.html">A. FAQ</a></span></dt><dt><span class="appendix"><a href="hbck.in.depth.html">B. hbck In Depth</a></span></dt><dd><dl><dt><span class="section"><a href="hbck.in.depth.html#d2475e11964">B.1. Running hbck to identify inconsistencies</a></span></dt><dt><span class="section"><a href="apbs02.html">B.2. Inconsistencies</a></span></dt><dt><spa
n class="section"><a href="apbs03.html">B.3. Localized repairs</a></span></dt><dt><span class="section"><a href="apbs04.html">B.4. Region Overlap Repairs</a></span></dt></dl></dd><dt><span class="appendix"><a href="compression.html">C. Compression In HBase</a></span></dt><dd><dl><dt><span class="section"><a href="compression.html#compression.test">C.1. CompressionTest Tool</a></span></dt><dt><span class="section"><a href="hbase.regionserver.codecs.html">C.2.
<code class="varname">
hbase.regionserver.codecs
</code>
@@ -40,9 +40,9 @@
GZIP
</a></span></dt><dt><span class="section"><a href="snappy.compression.html">C.5.
SNAPPY
- </a></span></dt><dt><span class="section"><a href="changing.compression.html">C.6. Changing Compression Schemes</a></span></dt></dl></dd><dt><span class="appendix"><a href="apd.html">D. YCSB: The Yahoo! Cloud Serving Benchmark and HBase</a></span></dt><dt><span class="appendix"><a href="hfilev2.html">E. HFile format version 2</a></span></dt><dd><dl><dt><span class="section"><a href="hfilev2.html#d2279e12005">E.1. Motivation </a></span></dt><dt><span class="section"><a href="apes02.html">E.2. HFile format version 1 overview </a></span></dt><dt><span class="section"><a href="apes03.html">E.3.
+ </a></span></dt><dt><span class="section"><a href="changing.compression.html">C.6. Changing Compression Schemes</a></span></dt></dl></dd><dt><span class="appendix"><a href="apd.html">D. YCSB: The Yahoo! Cloud Serving Benchmark and HBase</a></span></dt><dt><span class="appendix"><a href="hfilev2.html">E. HFile format version 2</a></span></dt><dd><dl><dt><span class="section"><a href="hfilev2.html#d2475e12260">E.1. Motivation </a></span></dt><dt><span class="section"><a href="apes02.html">E.2. HFile format version 1 overview </a></span></dt><dt><span class="section"><a href="apes03.html">E.3.
HBase file format with inline blocks (version 2)
- </a></span></dt></dl></dd><dt><span class="appendix"><a href="other.info.html">F. Other Information About HBase</a></span></dt><dd><dl><dt><span class="section"><a href="other.info.html#other.info.videos">F.1. HBase Videos</a></span></dt><dt><span class="section"><a href="other.info.pres.html">F.2. HBase Presentations (Slides)</a></span></dt><dt><span class="section"><a href="other.info.papers.html">F.3. HBase Papers</a></span></dt><dt><span class="section"><a href="other.info.sites.html">F.4. HBase Sites</a></span></dt><dt><span class="section"><a href="other.info.books.html">F.5. HBase Books</a></span></dt><dt><span class="section"><a href="other.info.books.hadoop.html">F.6. Hadoop Books</a></span></dt></dl></dd><dt><span class="appendix"><a href="hbase.history.html">G. HBase History</a></span></dt><dt><span class="appendix"><a href="asf.html">H. HBase and the Apache Software Foundation</a></span></dt><dd><dl><dt><span class="section"><a href="asf.html#asf.devprocess
">H.1. ASF Development Process</a></span></dt><dt><span class="section"><a href="asf.reporting.html">H.2. ASF Board Reporting</a></span></dt></dl></dd><dt><span class="appendix"><a href="tracing.html">I. Enabling Dapper-like Tracing in HBase</a></span></dt><dd><dl><dt><span class="section"><a href="tracing.html#tracing.spanreceivers">I.1. SpanReceivers</a></span></dt><dt><span class="section"><a href="tracing.client.modifications.html">I.2. Client Modifications</a></span></dt></dl></dd><dt><span class="appendix"><a href="hbase.rpc.html">J. 0.95 RPC Specification</a></span></dt><dd><dl><dt><span class="section"><a href="hbase.rpc.html#d2279e12710">J.1. Goals</a></span></dt><dt><span class="section"><a href="apjs02.html">J.2. TODO</a></span></dt><dt><span class="section"><a href="apjs03.html">J.3. RPC</a></span></dt><dt><span class="section"><a href="apjs04.html">J.4. Notes</a></span></dt></dl></dd><dt><span class="index"><a href="book_index.html">Index</a></span></dt></dl></d
iv><div class="list-of-tables"><p><b>List of Tables</b></p><dl><dt>2.1. <a href="configuration.html#d2279e486">Hadoop version support matrix</a></dt><dt>5.1. <a href="datamodel.html#d2279e3042">Table <code class="varname">webtable</code></a></dt><dt>5.2. <a href="physical.view.html#d2279e3126">ColumnFamily <code class="varname">anchor</code></a></dt><dt>5.3. <a href="physical.view.html#d2279e3165">ColumnFamily <code class="varname">contents</code></a></dt><dt>8.1. <a href="hbase.accesscontrol.configuration.html#d2279e4393">Operation To Permission Mapping</a></dt></dl></div></div><div id="disqus_thread"></div><script type="text/javascript">
+ </a></span></dt></dl></dd><dt><span class="appendix"><a href="other.info.html">F. Other Information About HBase</a></span></dt><dd><dl><dt><span class="section"><a href="other.info.html#other.info.videos">F.1. HBase Videos</a></span></dt><dt><span class="section"><a href="other.info.pres.html">F.2. HBase Presentations (Slides)</a></span></dt><dt><span class="section"><a href="other.info.papers.html">F.3. HBase Papers</a></span></dt><dt><span class="section"><a href="other.info.sites.html">F.4. HBase Sites</a></span></dt><dt><span class="section"><a href="other.info.books.html">F.5. HBase Books</a></span></dt><dt><span class="section"><a href="other.info.books.hadoop.html">F.6. Hadoop Books</a></span></dt></dl></dd><dt><span class="appendix"><a href="hbase.history.html">G. HBase History</a></span></dt><dt><span class="appendix"><a href="asf.html">H. HBase and the Apache Software Foundation</a></span></dt><dd><dl><dt><span class="section"><a href="asf.html#asf.devprocess
">H.1. ASF Development Process</a></span></dt><dt><span class="section"><a href="asf.reporting.html">H.2. ASF Board Reporting</a></span></dt></dl></dd><dt><span class="appendix"><a href="tracing.html">I. Enabling Dapper-like Tracing in HBase</a></span></dt><dd><dl><dt><span class="section"><a href="tracing.html#tracing.spanreceivers">I.1. SpanReceivers</a></span></dt><dt><span class="section"><a href="tracing.client.modifications.html">I.2. Client Modifications</a></span></dt></dl></dd><dt><span class="appendix"><a href="hbase.rpc.html">J. 0.95 RPC Specification</a></span></dt><dd><dl><dt><span class="section"><a href="hbase.rpc.html#d2475e12965">J.1. Goals</a></span></dt><dt><span class="section"><a href="apjs02.html">J.2. TODO</a></span></dt><dt><span class="section"><a href="apjs03.html">J.3. RPC</a></span></dt><dt><span class="section"><a href="apjs04.html">J.4. Notes</a></span></dt></dl></dd><dt><span class="index"><a href="book_index.html">Index</a></span></dt></dl></d
iv><div class="list-of-tables"><p><b>List of Tables</b></p><dl><dt>2.1. <a href="configuration.html#d2475e486">Hadoop version support matrix</a></dt><dt>5.1. <a href="datamodel.html#d2475e3046">Table <code class="varname">webtable</code></a></dt><dt>5.2. <a href="physical.view.html#d2475e3130">ColumnFamily <code class="varname">anchor</code></a></dt><dt>5.3. <a href="physical.view.html#d2475e3169">ColumnFamily <code class="varname">contents</code></a></dt><dt>8.1. <a href="hbase.accesscontrol.configuration.html#d2475e4626">Operation To Permission Mapping</a></dt></dl></div></div><div id="disqus_thread"></div><script type="text/javascript">
var disqus_shortname = 'hbase'; // required: replace example with your forum shortname
var disqus_url = 'http://hbase.apache.org/book';
var disqus_identifier = 'book';
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@@ -1,33 +1,33 @@
<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
- <title>13.3. Performance/Troubleshooting</title><link rel="stylesheet" type="text/css" href="../css/freebsd_docbook.css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><link rel="home" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="up" href="casestudies.html" title="Chapter 13. Apache HBase (TM) Case Studies"><link rel="prev" href="casestudies.schema.html" title="13.2. Schema Design"><link rel="next" href="ops_mgt.html" title="Chapter 14. Apache HBase (TM) Operational Management"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">13.3. Performance/Troubleshooting</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="casestudies.schema.html">Prev</a> </td><th width="60%" align="center">Chapter 13. Apache HBase (TM) Case Stu
dies</th><td width="20%" align="right"> <a accesskey="n" href="ops_mgt.html">Next</a></td></tr></table><hr></div><div class="section" title="13.3. Performance/Troubleshooting"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="casestudies.perftroub"></a>13.3. Performance/Troubleshooting</h2></div></div></div><div class="section" title="13.3.1. Case Study #1 (Performance Issue On A Single Node)"><div class="titlepage"><div><div><h3 class="title"><a name="casestudies.slownode"></a>13.3.1. Case Study #1 (Performance Issue On A Single Node)</h3></div></div></div><div class="section" title="13.3.1.1. Scenario"><div class="titlepage"><div><div><h4 class="title"><a name="d2279e8660"></a>13.3.1.1. Scenario</h4></div></div></div><p>Following a scheduled reboot, one data node began exhibiting unusual behavior. Routine MapReduce
+ <title>13.3. Performance/Troubleshooting</title><link rel="stylesheet" type="text/css" href="../css/freebsd_docbook.css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><link rel="home" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="up" href="casestudies.html" title="Chapter 13. Apache HBase (TM) Case Studies"><link rel="prev" href="casestudies.schema.html" title="13.2. Schema Design"><link rel="next" href="ops_mgt.html" title="Chapter 14. Apache HBase (TM) Operational Management"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">13.3. Performance/Troubleshooting</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="casestudies.schema.html">Prev</a> </td><th width="60%" align="center">Chapter 13. Apache HBase (TM) Case Stu
dies</th><td width="20%" align="right"> <a accesskey="n" href="ops_mgt.html">Next</a></td></tr></table><hr></div><div class="section" title="13.3. Performance/Troubleshooting"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="casestudies.perftroub"></a>13.3. Performance/Troubleshooting</h2></div></div></div><div class="section" title="13.3.1. Case Study #1 (Performance Issue On A Single Node)"><div class="titlepage"><div><div><h3 class="title"><a name="casestudies.slownode"></a>13.3.1. Case Study #1 (Performance Issue On A Single Node)</h3></div></div></div><div class="section" title="13.3.1.1. Scenario"><div class="titlepage"><div><div><h4 class="title"><a name="d2475e8904"></a>13.3.1.1. Scenario</h4></div></div></div><p>Following a scheduled reboot, one data node began exhibiting unusual behavior. Routine MapReduce
jobs run against HBase tables which regularly completed in five or six minutes began taking 30 or 40 minutes
to finish. These jobs were consistently found to be waiting on map and reduce tasks assigned to the troubled data node
(e.g., the slow map tasks all had the same Input Split).
The situation came to a head during a distributed copy, when the copy was severely prolonged by the lagging node.
- </p></div><div class="section" title="13.3.1.2. Hardware"><div class="titlepage"><div><div><h4 class="title"><a name="d2279e8665"></a>13.3.1.2. Hardware</h4></div></div></div><p>Datanodes:
+ </p></div><div class="section" title="13.3.1.2. Hardware"><div class="titlepage"><div><div><h4 class="title"><a name="d2475e8909"></a>13.3.1.2. Hardware</h4></div></div></div><p>Datanodes:
</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">Two 12-core processors</li><li class="listitem">Six Enerprise SATA disks</li><li class="listitem">24GB of RAM</li><li class="listitem">Two bonded gigabit NICs</li></ul></div><p>
</p><p>Network:
</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">10 Gigabit top-of-rack switches</li><li class="listitem">20 Gigabit bonded interconnects between racks.</li></ul></div><p>
- </p></div><div class="section" title="13.3.1.3. Hypotheses"><div class="titlepage"><div><div><h4 class="title"><a name="d2279e8688"></a>13.3.1.3. Hypotheses</h4></div></div></div><div class="section" title="13.3.1.3.1. HBase "Hot Spot" Region"><div class="titlepage"><div><div><h5 class="title"><a name="d2279e8691"></a>13.3.1.3.1. HBase "Hot Spot" Region</h5></div></div></div><p>We hypothesized that we were experiencing a familiar point of pain: a "hot spot" region in an HBase table,
+ </p></div><div class="section" title="13.3.1.3. Hypotheses"><div class="titlepage"><div><div><h4 class="title"><a name="d2475e8932"></a>13.3.1.3. Hypotheses</h4></div></div></div><div class="section" title="13.3.1.3.1. HBase "Hot Spot" Region"><div class="titlepage"><div><div><h5 class="title"><a name="d2475e8935"></a>13.3.1.3.1. HBase "Hot Spot" Region</h5></div></div></div><p>We hypothesized that we were experiencing a familiar point of pain: a "hot spot" region in an HBase table,
where uneven key-space distribution can funnel a huge number of requests to a single HBase region, bombarding the RegionServer
process and cause slow response time. Examination of the HBase Master status page showed that the number of HBase requests to the
troubled node was almost zero. Further, examination of the HBase logs showed that there were no region splits, compactions, or other region transitions
in progress. This effectively ruled out a "hot spot" as the root cause of the observed slowness.
- </p></div><div class="section" title="13.3.1.3.2. HBase Region With Non-Local Data"><div class="titlepage"><div><div><h5 class="title"><a name="d2279e8696"></a>13.3.1.3.2. HBase Region With Non-Local Data</h5></div></div></div><p>Our next hypothesis was that one of the MapReduce tasks was requesting data from HBase that was not local to the datanode, thus
+ </p></div><div class="section" title="13.3.1.3.2. HBase Region With Non-Local Data"><div class="titlepage"><div><div><h5 class="title"><a name="d2475e8940"></a>13.3.1.3.2. HBase Region With Non-Local Data</h5></div></div></div><p>Our next hypothesis was that one of the MapReduce tasks was requesting data from HBase that was not local to the datanode, thus
forcing HDFS to request data blocks from other servers over the network. Examination of the datanode logs showed that there were very
few blocks being requested over the network, indicating that the HBase region was correctly assigned, and that the majority of the necessary
data was located on the node. This ruled out the possibility of non-local data causing a slowdown.
- </p></div><div class="section" title="13.3.1.3.3. Excessive I/O Wait Due To Swapping Or An Over-Worked Or Failing Hard Disk"><div class="titlepage"><div><div><h5 class="title"><a name="d2279e8701"></a>13.3.1.3.3. Excessive I/O Wait Due To Swapping Or An Over-Worked Or Failing Hard Disk</h5></div></div></div><p>After concluding that the Hadoop and HBase were not likely to be the culprits, we moved on to troubleshooting the datanode's hardware.
+ </p></div><div class="section" title="13.3.1.3.3. Excessive I/O Wait Due To Swapping Or An Over-Worked Or Failing Hard Disk"><div class="titlepage"><div><div><h5 class="title"><a name="d2475e8945"></a>13.3.1.3.3. Excessive I/O Wait Due To Swapping Or An Over-Worked Or Failing Hard Disk</h5></div></div></div><p>After concluding that the Hadoop and HBase were not likely to be the culprits, we moved on to troubleshooting the datanode's hardware.
Java, by design, will periodically scan its entire memory space to do garbage collection. If system memory is heavily overcommitted, the Linux
kernel may enter a vicious cycle, using up all of its resources swapping Java heap back and forth from disk to RAM as Java tries to run garbage
collection. Further, a failing hard disk will often retry reads and/or writes many times before giving up and returning an error. This can manifest
as high iowait, as running processes wait for reads and writes to complete. Finally, a disk nearing the upper edge of its performance envelope will
begin to cause iowait as it informs the kernel that it cannot accept any more data, and the kernel queues incoming data into the dirty write pool in memory.
However, using <code class="code">vmstat(1)</code> and <code class="code">free(1)</code>, we could see that no swap was being used, and the amount of disk IO was only a few kilobytes per second.
- </p></div><div class="section" title="13.3.1.3.4. Slowness Due To High Processor Usage"><div class="titlepage"><div><div><h5 class="title"><a name="d2279e8712"></a>13.3.1.3.4. Slowness Due To High Processor Usage</h5></div></div></div><p>Next, we checked to see whether the system was performing slowly simply due to very high computational load. <code class="code">top(1)</code> showed that the system load
+ </p></div><div class="section" title="13.3.1.3.4. Slowness Due To High Processor Usage"><div class="titlepage"><div><div><h5 class="title"><a name="d2475e8956"></a>13.3.1.3.4. Slowness Due To High Processor Usage</h5></div></div></div><p>Next, we checked to see whether the system was performing slowly simply due to very high computational load. <code class="code">top(1)</code> showed that the system load
was higher than normal, but <code class="code">vmstat(1)</code> and <code class="code">mpstat(1)</code> showed that the amount of processor being used for actual computation was low.
- </p></div><div class="section" title="13.3.1.3.5. Network Saturation (The Winner)"><div class="titlepage"><div><div><h5 class="title"><a name="d2279e8726"></a>13.3.1.3.5. Network Saturation (The Winner)</h5></div></div></div><p>Since neither the disks nor the processors were being utilized heavily, we moved on to the performance of the network interfaces. The datanode had two
+ </p></div><div class="section" title="13.3.1.3.5. Network Saturation (The Winner)"><div class="titlepage"><div><div><h5 class="title"><a name="d2475e8970"></a>13.3.1.3.5. Network Saturation (The Winner)</h5></div></div></div><p>Since neither the disks nor the processors were being utilized heavily, we moved on to the performance of the network interfaces. The datanode had two
gigabit ethernet adapters, bonded to form an active-standby interface. <code class="code">ifconfig(8)</code> showed some unusual anomalies, namely interface errors, overruns, framing errors.
While not unheard of, these kinds of errors are exceedingly rare on modern hardware which is operating as it should:
</p><pre class="programlisting">
@@ -72,7 +72,7 @@ Current message level: 0x00000003 (3)
Link detected: yes
</pre><p>
</p><p>In normal operation, the ICMP ping round trip time should be around 20ms, and the interface speed and duplex should read, "1000MB/s", and, "Full", respectively.
- </p></div></div><div class="section" title="13.3.1.4. Resolution"><div class="titlepage"><div><div><h4 class="title"><a name="d2279e8747"></a>13.3.1.4. Resolution</h4></div></div></div><p>After determining that the active ethernet adapter was at the incorrect speed, we used the <code class="code">ifenslave(8)</code> command to make the standby interface
+ </p></div></div><div class="section" title="13.3.1.4. Resolution"><div class="titlepage"><div><div><h4 class="title"><a name="d2475e8991"></a>13.3.1.4. Resolution</h4></div></div></div><p>After determining that the active ethernet adapter was at the incorrect speed, we used the <code class="code">ifenslave(8)</code> command to make the standby interface
the active interface, which yielded an immediate improvement in MapReduce performance, and a 10 times improvement in network throughput:
</p><p>On the next trip to the datacenter, we determined that the line speed issue was ultimately caused by a bad network cable, which was replaced.
</p></div></div><div class="section" title="13.3.2. Case Study #2 (Performance Research 2012)"><div class="titlepage"><div><div><h3 class="title"><a name="casestudies.perf.1"></a>13.3.2. Case Study #2 (Performance Research 2012)</h3></div></div></div><p>Investigation results of a self-described "we're not sure what's wrong, but it seems slow" problem.
Modified: hbase/hbase.apache.org/trunk/book/cells.html
URL: http://svn.apache.org/viewvc/hbase/hbase.apache.org/trunk/book/cells.html?rev=1463652&r1=1463651&r2=1463652&view=diff
==============================================================================
--- hbase/hbase.apache.org/trunk/book/cells.html (original)
+++ hbase/hbase.apache.org/trunk/book/cells.html Tue Apr 2 18:06:19 2013
@@ -1,6 +1,6 @@
<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
- <title>5.6. Cells</title><link rel="stylesheet" type="text/css" href="../css/freebsd_docbook.css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><link rel="home" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="up" href="datamodel.html" title="Chapter 5. Data Model"><link rel="prev" href="columnfamily.html" title="5.5. Column Family"><link rel="next" href="data_model_operations.html" title="5.7. Data Model Operations"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">5.6. Cells</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="columnfamily.html">Prev</a> </td><th width="60%" align="center">Chapter 5. Data Model</th><td width="20%" align="right"> <a accesskey="n" href="data_model_operations.html">Next</a></td></tr></tabl
e><hr></div><div class="section" title="5.6. Cells"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="cells"></a>5.6. Cells<a class="indexterm" name="d2279e3300"></a></h2></div></div></div><p>A <span class="emphasis"><em>{row, column, version} </em></span>tuple exactly
+ <title>5.6. Cells</title><link rel="stylesheet" type="text/css" href="../css/freebsd_docbook.css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><link rel="home" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="up" href="datamodel.html" title="Chapter 5. Data Model"><link rel="prev" href="columnfamily.html" title="5.5. Column Family"><link rel="next" href="data_model_operations.html" title="5.7. Data Model Operations"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">5.6. Cells</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="columnfamily.html">Prev</a> </td><th width="60%" align="center">Chapter 5. Data Model</th><td width="20%" align="right"> <a accesskey="n" href="data_model_operations.html">Next</a></td></tr></tabl
e><hr></div><div class="section" title="5.6. Cells"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="cells"></a>5.6. Cells<a class="indexterm" name="d2475e3304"></a></h2></div></div></div><p>A <span class="emphasis"><em>{row, column, version} </em></span>tuple exactly
specifies a <code class="literal">cell</code> in HBase.
Cell content is uninterrpreted bytes</p></div><div id="disqus_thread"></div><script type="text/javascript">
var disqus_shortname = 'hbase'; // required: replace example with your forum shortname
Modified: hbase/hbase.apache.org/trunk/book/columnfamily.html
URL: http://svn.apache.org/viewvc/hbase/hbase.apache.org/trunk/book/columnfamily.html?rev=1463652&r1=1463651&r2=1463652&view=diff
==============================================================================
--- hbase/hbase.apache.org/trunk/book/columnfamily.html (original)
+++ hbase/hbase.apache.org/trunk/book/columnfamily.html Tue Apr 2 18:06:19 2013
@@ -1,13 +1,13 @@
<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
- <title>5.5. Column Family</title><link rel="stylesheet" type="text/css" href="../css/freebsd_docbook.css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><link rel="home" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="up" href="datamodel.html" title="Chapter 5. Data Model"><link rel="prev" href="row.html" title="5.4. Row"><link rel="next" href="cells.html" title="5.6. Cells"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">5.5. Column Family</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="row.html">Prev</a> </td><th width="60%" align="center">Chapter 5. Data Model</th><td width="20%" align="right"> <a accesskey="n" href="cells.html">Next</a></td></tr></table><hr></div><div class="section" title="5.5. Column Fam
ily"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="columnfamily"></a>5.5. Column Family<a class="indexterm" name="d2279e3261"></a></h2></div></div></div><p>
+ <title>5.5. Column Family</title><link rel="stylesheet" type="text/css" href="../css/freebsd_docbook.css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><link rel="home" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="up" href="datamodel.html" title="Chapter 5. Data Model"><link rel="prev" href="row.html" title="5.4. Row"><link rel="next" href="cells.html" title="5.6. Cells"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">5.5. Column Family</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="row.html">Prev</a> </td><th width="60%" align="center">Chapter 5. Data Model</th><td width="20%" align="right"> <a accesskey="n" href="cells.html">Next</a></td></tr></table><hr></div><div class="section" title="5.5. Column Fam
ily"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="columnfamily"></a>5.5. Column Family<a class="indexterm" name="d2475e3265"></a></h2></div></div></div><p>
Columns in Apache HBase are grouped into <span class="emphasis"><em>column families</em></span>.
All column members of a column family have the same prefix. For example, the
columns <span class="emphasis"><em>courses:history</em></span> and
<span class="emphasis"><em>courses:math</em></span> are both members of the
<span class="emphasis"><em>courses</em></span> column family.
The colon character (<code class="literal">:</code>) delimits the column family from the
- <a class="indexterm" name="d2279e3281"></a>.
+ <a class="indexterm" name="d2475e3285"></a>.
The column family prefix must be composed of
<span class="emphasis"><em>printable</em></span> characters. The qualifying tail, the
column family <span class="emphasis"><em>qualifier</em></span>, can be made of any
Modified: hbase/hbase.apache.org/trunk/book/community.html
URL: http://svn.apache.org/viewvc/hbase/hbase.apache.org/trunk/book/community.html?rev=1463652&r1=1463651&r2=1463652&view=diff
==============================================================================
--- hbase/hbase.apache.org/trunk/book/community.html (original)
+++ hbase/hbase.apache.org/trunk/book/community.html Tue Apr 2 18:06:19 2013
@@ -3,7 +3,7 @@
<title>Chapter 17. Community</title><link rel="stylesheet" type="text/css" href="../css/freebsd_docbook.css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><link rel="home" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="up" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="prev" href="zk.sasl.auth.html" title="16.2. SASL Authentication with ZooKeeper"><link rel="next" href="community.roles.html" title="17.2. Community Roles"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 17. Community</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="zk.sasl.auth.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="community.roles.html">Next</a></
td></tr></table><hr></div><div class="chapter" title="Chapter 17. Community"><div class="titlepage"><div><div><h2 class="title"><a name="community"></a>Chapter 17. Community</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="community.html#decisions">17.1. Decisions</a></span></dt><dd><dl><dt><span class="section"><a href="community.html#feature_branches">17.1.1. Feature Branches</a></span></dt><dt><span class="section"><a href="community.html#patchplusonepolicy">17.1.2. Patch +1 Policy</a></span></dt></dl></dd><dt><span class="section"><a href="community.roles.html">17.2. Community Roles</a></span></dt><dd><dl><dt><span class="section"><a href="community.roles.html#OWNER">17.2.1. Component Owner</a></span></dt></dl></dd></dl></div><div class="section" title="17.1. Decisions"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="decisions"></a>17.1. Decisions</h2
></div></div></div><div class="section" title="17.1.1. Feature Branches"><div class="titlepage"><div><div><h3 class="title"><a name="feature_branches"></a>17.1.1. Feature Branches</h3></div></div></div><p>Feature Branches are easy to make. You do not have to be a committer to make one. Just request the name of your branch be added to JIRA up on the
developer's mailing list and a committer will add it for you. Thereafter you can file issues against your feature branch in Apache HBase (TM) JIRA. Your code you
keep elsewhere -- it should be public so it can be observed -- and you can update dev mailing list on progress. When the feature is ready for commit,
- 3 +1s from committers will get your feature merged<sup>[<a name="d2279e11429" href="#ftn.d2279e11429" class="footnote">31</a>]</sup>
+ 3 +1s from committers will get your feature merged<sup>[<a name="d2475e11684" href="#ftn.d2475e11684" class="footnote">31</a>]</sup>
</p></div><div class="section" title="17.1.2. Patch +1 Policy"><div class="titlepage"><div><div><h3 class="title"><a name="patchplusonepolicy"></a>17.1.2. Patch +1 Policy</h3></div></div></div><p>
The below policy is something we put in place 09/2012. It is a
suggested policy rather than a hard requirement. We want to try it
@@ -27,7 +27,7 @@ first pass).
</p><p>
Any -1 on a patch by anyone vetos a patch; it cannot be committed
until the justification for the -1 is addressed.
-</p></div></div><div class="footnotes"><br><hr width="100" align="left"><div class="footnote"><p><sup>[<a id="ftn.d2279e11429" href="#d2279e11429" class="para">31</a>] </sup>See <a class="link" href="http://search-hadoop.com/m/asM982C5FkS1" target="_top">HBase, mail # dev - Thoughts about large feature dev branches</a></p></div></div></div><div id="disqus_thread"></div><script type="text/javascript">
+</p></div></div><div class="footnotes"><br><hr width="100" align="left"><div class="footnote"><p><sup>[<a id="ftn.d2475e11684" href="#d2475e11684" class="para">31</a>] </sup>See <a class="link" href="http://search-hadoop.com/m/asM982C5FkS1" target="_top">HBase, mail # dev - Thoughts about large feature dev branches</a></p></div></div></div><div id="disqus_thread"></div><script type="text/javascript">
var disqus_shortname = 'hbase'; // required: replace example with your forum shortname
var disqus_url = 'http://hbase.apache.org/book';
var disqus_identifier = 'community';
Modified: hbase/hbase.apache.org/trunk/book/compression.html
URL: http://svn.apache.org/viewvc/hbase/hbase.apache.org/trunk/book/compression.html?rev=1463652&r1=1463651&r2=1463652&view=diff
==============================================================================
--- hbase/hbase.apache.org/trunk/book/compression.html (original)
+++ hbase/hbase.apache.org/trunk/book/compression.html Tue Apr 2 18:06:19 2013
@@ -1,6 +1,6 @@
<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
- <title>Appendix C. Compression In HBase</title><link rel="stylesheet" type="text/css" href="../css/freebsd_docbook.css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><link rel="home" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="up" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="prev" href="apbs04.html" title="B.4. Region Overlap Repairs"><link rel="next" href="hbase.regionserver.codecs.html" title="C.2. hbase.regionserver.codecs"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Appendix C. Compression In HBase</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="apbs04.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="hbase.regionser
ver.codecs.html">Next</a></td></tr></table><hr></div><div class="appendix" title="Appendix C. Compression In HBase"><div class="titlepage"><div><div><h2 class="title"><a name="compression"></a>Appendix C. Compression In HBase<a class="indexterm" name="d2279e11860"></a></h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="compression.html#compression.test">C.1. CompressionTest Tool</a></span></dt><dt><span class="section"><a href="hbase.regionserver.codecs.html">C.2.
+ <title>Appendix C. Compression In HBase</title><link rel="stylesheet" type="text/css" href="../css/freebsd_docbook.css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.76.1"><link rel="home" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="up" href="book.html" title="The Apache HBase™ Reference Guide"><link rel="prev" href="apbs04.html" title="B.4. Region Overlap Repairs"><link rel="next" href="hbase.regionserver.codecs.html" title="C.2. hbase.regionserver.codecs"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Appendix C. Compression In HBase</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="apbs04.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="hbase.regionser
ver.codecs.html">Next</a></td></tr></table><hr></div><div class="appendix" title="Appendix C. Compression In HBase"><div class="titlepage"><div><div><h2 class="title"><a name="compression"></a>Appendix C. Compression In HBase<a class="indexterm" name="d2475e12115"></a></h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="compression.html#compression.test">C.1. CompressionTest Tool</a></span></dt><dt><span class="section"><a href="hbase.regionserver.codecs.html">C.2.
<code class="varname">
hbase.regionserver.codecs
</code>
Modified: hbase/hbase.apache.org/trunk/book/config.files.html
URL: http://svn.apache.org/viewvc/hbase/hbase.apache.org/trunk/book/config.files.html?rev=1463652&r1=1463651&r2=1463652&view=diff
==============================================================================
--- hbase/hbase.apache.org/trunk/book/config.files.html (original)
+++ hbase/hbase.apache.org/trunk/book/config.files.html Tue Apr 2 18:06:19 2013
@@ -36,7 +36,7 @@ The documentation below is generated usi
Change this setting to point to a location more permanent
than '/tmp' (The '/tmp' directory is often cleared on
machine restart).
- </p><p>Default: <code class="varname">${java.io.tmpdir}/hbase-${user.name}</code></p></dd><dt><a name="hbase.local.dir"></a><code class="varname">hbase.local.dir</code></dt><dd><p>Directory on the local filesystem to be used
+ </p><p>Default: <code class="varname">${java.io.tmpdir}/hbase-${user.name}</code></p></dd><dt><a name="hbase.local.dir"></a><code class="varname">hbase.local.dir</code></dt><dd><p>Directory on the local filesystem to be used
as a local storage.
</p><p>Default: <code class="varname">${hbase.tmp.dir}/local/</code></p></dd><dt><a name="hbase.master.info.port"></a><code class="varname">hbase.master.info.port</code></dt><dd><p>The port for the HBase Master web UI.
Set to -1 if you do not want a UI instance run.
@@ -190,7 +190,7 @@ The documentation below is generated usi
Enables StoreFileScanner parallel-seeking in StoreScanner,
a feature which can reduce response latency under special conditions.
</p><p>Default: <code class="varname">false</code></p></dd><dt><a name="hbase.storescanner.parallel.seek.threads"></a><code class="varname">hbase.storescanner.parallel.seek.threads</code></dt><dd><p>
- The default thread pool size if parallel-seeking feature enabled.
+ The default thread pool size if parallel-seeking feature enabled.
</p><p>Default: <code class="varname">10</code></p></dd><dt><a name="hbase.mapreduce.hfileoutputformat.blocksize"></a><code class="varname">hbase.mapreduce.hfileoutputformat.blocksize</code></dt><dd><p>The mapreduce HFileOutputFormat writes storefiles/hfiles.
This is the minimum hfile blocksize to emit. Usually in hbase, writing
hfiles, the blocksize is gotten from the table schema (HColumnDescriptor)
@@ -252,7 +252,7 @@ The documentation below is generated usi
</p><p>Default: <code class="varname">hbase-policy.xml</code></p></dd><dt><a name="hbase.superuser"></a><code class="varname">hbase.superuser</code></dt><dd><p>List of users or groups (comma-separated), who are allowed
full privileges, regardless of stored ACLs, across the cluster.
Only used when HBase security is enabled.
- </p><p>Default: <code class="varname"></code></p></dd><dt><a name="hbase.auth.key.update.interval"></a><code class="varname">hbase.auth.key.update.interval</code></dt><dd><p>The update interval for master key for authentication tokens
+ </p><p>Default: <code class="varname"></code></p></dd><dt><a name="hbase.auth.key.update.interval"></a><code class="varname">hbase.auth.key.update.interval</code></dt><dd><p>The update interval for master key for authentication tokens
in servers in milliseconds. Only used when HBase security is enabled.
</p><p>Default: <code class="varname">86400000</code></p></dd><dt><a name="hbase.auth.token.max.lifetime"></a><code class="varname">hbase.auth.token.max.lifetime</code></dt><dd><p>The maximum lifetime in milliseconds after which an
authentication token expires. Only used when HBase security is enabled.
@@ -295,7 +295,7 @@ The documentation below is generated usi
for more information.
</p><p>Default: <code class="varname">3888</code></p></dd><dt><a name="hbase.zookeeper.useMulti"></a><code class="varname">hbase.zookeeper.useMulti</code></dt><dd><p>Instructs HBase to make use of ZooKeeper's multi-update functionality.
This allows certain ZooKeeper operations to complete more quickly and prevents some issues
- with rare Replication failure scenarios (see the release note of HBASE-2611 for an example).
+ with rare Replication failure scenarios (see the release note of HBASE-2611 for an example).
IMPORTANT: only set this to true if all ZooKeeper servers in the cluster are on version 3.4+
and will not be downgraded. ZooKeeper versions before 3.4 do not support multi-update and will
not fail gracefully if multi-update is invoked (see ZOOKEEPER-1495).
@@ -332,7 +332,7 @@ The documentation below is generated usi
environments where one wants to terminate the server as soon as possible to
simplify coprocessor failure analysis.
</p><p>Default: <code class="varname">false</code></p></dd><dt><a name="hbase.online.schema.update.enable"></a><code class="varname">hbase.online.schema.update.enable</code></dt><dd><p>
- Set true to enable online schema changes. This is an experimental feature.
+ Set true to enable online schema changes. This is an experimental feature.
There are known issues modifying table schemas at the same time a region
split is happening so your table needs to be quiescent or else you have to
be running with splits disabled.
@@ -371,10 +371,7 @@ The documentation below is generated usi
</p><p>Default: <code class="varname">true</code></p></dd><dt><a name="hbase.metrics.exposeOperationTimes"></a><code class="varname">hbase.metrics.exposeOperationTimes</code></dt><dd><p>Whether to report metrics about time taken performing an
operation on the region server. Get, Put, Delete, Increment, and Append can all
have their times exposed through Hadoop metrics per CF and per region.
- </p><p>Default: <code class="varname">true</code></p></dd><dt><a name="hbase.table.archive.directory"></a><code class="varname">hbase.table.archive.directory</code></dt><dd><p>Per-table directory name under which to backup files for a
- table. Files are moved to the same directories as they would be under the
- table directory, but instead are just one level lower (under
- table/.archive/... rather than table/...). Currently only applies to HFiles.</p><p>Default: <code class="varname">.archive</code></p></dd><dt><a name="hbase.master.hfilecleaner.plugins"></a><code class="varname">hbase.master.hfilecleaner.plugins</code></dt><dd><p>A comma-separated list of HFileCleanerDelegate invoked by
+ </p><p>Default: <code class="varname">true</code></p></dd><dt><a name="hbase.master.hfilecleaner.plugins"></a><code class="varname">hbase.master.hfilecleaner.plugins</code></dt><dd><p>A comma-separated list of HFileCleanerDelegate invoked by
the HFileCleaner service. These HFiles cleaners are called in order,
so put the cleaner that prunes the most files in front. To
implement your own HFileCleanerDelegate, just put it in HBase's classpath