From 2bc0e1ed3a59cfeaeffdc979829b4ea9a527384b Mon Sep 17 00:00:00 2001 From: Michael Stack Date: Mon, 17 May 2010 21:07:48 +0000 Subject: [PATCH] HBASE-2382 Don't rely on fs.getDefaultReplication() to roll HLogs; committed the overview.html changes only git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@945364 13f79535-47bb-0310-9956-ffa450edef68 --- CHANGES.txt | 4 ++++ core/src/main/javadoc/overview.html | 31 +++++++++++++++++++++++------ 2 files changed, 29 insertions(+), 6 deletions(-) diff --git a/CHANGES.txt b/CHANGES.txt index 23f298bd799..795ef7d4370 100644 --- a/CHANGES.txt +++ b/CHANGES.txt @@ -320,6 +320,10 @@ Release 0.21.0 - Unreleased the merge of old 0.20 into TRUNK task) -- part 1. HBASE-2474 Bug in HBASE-2248 - mixed version reads (not allowed by spec) HBASE-2509 NPEs in various places, HRegion.get, HRS.close + HBASE-2344 InfoServer and hence HBase Master doesn't fully start if you + have HADOOP-6151 patch (Kannan Muthukkaruppan via Stack) + HBASE-2382 Don't rely on fs.getDefaultReplication() to roll HLogs + (Nicolas Spiegelberg via Stack) IMPROVEMENTS HBASE-1760 Cleanup TODOs in HTable diff --git a/core/src/main/javadoc/overview.html b/core/src/main/javadoc/overview.html index 45251d90080..230f98758ed 100644 --- a/core/src/main/javadoc/overview.html +++ b/core/src/main/javadoc/overview.html @@ -150,14 +150,23 @@ requirements and instructions for how to set up a DFS.

Pseudo-distributed mode

A pseudo-distributed mode is simply a distributed mode run on a single host. -Once you have confirmed your DFS setup, configuring HBase for use on one host requires modification of +Use this configuration testing and prototyping on hbase. Do not use this configuration +for production nor for evaluating HBase performance. +

+

Once you have confirmed your DFS setup, configuring HBase for use on one host requires modification of ${HBASE_HOME}/conf/hbase-site.xml, which needs to be pointed at the running Hadoop DFS instance. Use hbase-site.xml to override the properties defined in ${HBASE_HOME}/conf/hbase-default.xml (hbase-default.xml itself -should never be modified). At a minimum the hbase.rootdir property should be redefined -in hbase-site.xml to point HBase at the Hadoop filesystem to use. For example, adding the property -below to your hbase-site.xml says that HBase should use the /hbase directory in the -HDFS whose namenode is at port 9000 on your local machine:

+should never be modified) and for HDFS client configurations. +At a minimum, the hbase.rootdir, +which points HBase at the Hadoop filesystem to use, +and the dfs.replication, an hdfs client-side +configuration stipulating how many replicas to keep up, +should be redefined in hbase-site.xml. For example, +adding the properties below to your hbase-site.xml says that HBase +should use the /hbase +directory in the HDFS whose namenode is at port 9000 on your local machine, and that +it should run with one replica only (recommended for pseudo-distributed mode):

 <configuration>
@@ -168,6 +177,12 @@ HDFS whose namenode is at port 9000 on your local machine:

     <description>The directory shared by region servers.
     </description>
   </property>
+  <property>
+    <name>dfs.replication</name>
+    <value>1</value>
+    <description>The replication count for HLog & HFile storage. Should not be greater than HDFS datanode count.
+    </description>
+  </property>
   ...
 </configuration>
@@ -203,7 +218,11 @@ configurations must be made in addition to those described in the

In fully-distributed mode, you probably want to change your hbase.rootdir -from localhost to the name of the node running the HDFS NameNode. In addition +from localhost to the name of the node running the HDFS NameNode and you should set +the dfs.replication to be the number of datanodes you have in your cluster or 3, which +ever is the smaller. +

+

In addition to hbase-site.xml changes, a fully-distributed mode requires that you modify ${HBASE_HOME}/conf/regionservers. The regionserver file lists all hosts running HRegionServers, one host per line