You are viewing a plain text version of this content. The canonical link for it is here.
Posted to common-commits@hadoop.apache.org by dd...@apache.org on 2008/06/17 12:46:43 UTC
svn commit: r668612 [3/3] - in /hadoop/core/trunk: ./ docs/
src/docs/src/documentation/content/xdocs/
Modified: hadoop/core/trunk/src/docs/src/documentation/content/xdocs/cluster_setup.xml
URL: http://svn.apache.org/viewvc/hadoop/core/trunk/src/docs/src/documentation/content/xdocs/cluster_setup.xml?rev=668612&r1=668611&r2=668612&view=diff
==============================================================================
--- hadoop/core/trunk/src/docs/src/documentation/content/xdocs/cluster_setup.xml (original)
+++ hadoop/core/trunk/src/docs/src/documentation/content/xdocs/cluster_setup.xml Tue Jun 17 03:46:42 2008
@@ -118,6 +118,25 @@
<code>JAVA_HOME</code> so that it is correctly defined on each
remote node.</p>
+ <p>Administrators can configure individual daemons using the
+ configuration options <code>HADOOP_*_OPTS</code>. Various options
+ available are shown below in the table. </p>
+ <table>
+ <tr><th>Daemon</th><th>Configure Options</th></tr>
+ <tr><td>NameNode</td><td>HADOOP_NAMENODE_OPTS</td></tr>
+ <tr><td>DataNode</td><td>HADOOP_DATANODE_OPTS</td></tr>
+ <tr><td>SecondaryNamenode</td>
+ <td>HADOOP_SECONDARYNAMENODE_OPTS</td></tr>
+ <tr><td>JobTracker</td><td>HADOOP_JOBTRACKER_OPTS</td></tr>
+ <tr><td>TaskTracker</td><td>HADOOP_TASKTRACKER_OPTS</td></tr>
+ </table>
+
+ <p> For example, To configure Namenode to use parallelGC, the
+ following statement should be added in <code>hadoop-env.sh</code> :
+ <br/><code>
+ export HADOOP_NAMENODE_OPTS="-XX:+UseParallelGC ${HADOOP_NAMENODE_OPTS}"
+ </code><br/></p>
+
<p>Other useful configuration parameters that you can customize
include:</p>
<ul>
@@ -128,7 +147,9 @@
</li>
<li>
<code>HADOOP_HEAPSIZE</code> - The maximum amount of heapsize
- to use, in MB e.g. <code>2000MB</code>.
+ to use, in MB e.g. <code>1000MB</code>. This is used to
+ configure the heap size for the hadoop daemon. By default,
+ the value is <code>1000MB</code>.
</li>
</ul>
</section>
@@ -335,7 +356,7 @@
<tr>
<td>mapred.child.java.opts</td>
<td>-Xmx1024M</td>
- <td></td>
+ <td>Larger heap-size for child jvms of maps/reduces.</td>
</tr>
</table>
</li>
Modified: hadoop/core/trunk/src/docs/src/documentation/content/xdocs/mapred_tutorial.xml
URL: http://svn.apache.org/viewvc/hadoop/core/trunk/src/docs/src/documentation/content/xdocs/mapred_tutorial.xml?rev=668612&r1=668611&r2=668612&view=diff
==============================================================================
--- hadoop/core/trunk/src/docs/src/documentation/content/xdocs/mapred_tutorial.xml (original)
+++ hadoop/core/trunk/src/docs/src/documentation/content/xdocs/mapred_tutorial.xml Tue Jun 17 03:46:42 2008
@@ -1066,7 +1066,17 @@
</p>
<p>Users/admins can also specify the maximum virtual memory
- of the launched child-task using <code>mapred.child.ulimit</code>.</p>
+ of the launched child-task using <code>mapred.child.ulimit</code>.
+ The value for <code>mapred.child.ulimit</code> should be specified
+ in kilo bytes (KB). And also the value must be greater than
+ or equal to the -Xmx passed to JavaVM, else the VM might not start.
+ </p>
+
+ <p>Note: <code>mapred.child.java.opts</code> are used only for
+ configuring the launched child tasks from task tracker. Configuring
+ the memory options for daemons is documented in
+ <a href="cluster_setup.html#Configuring+the+Environment+of+the+Hadoop+Daemons">
+ cluster_setup.html </a></p>
<p>The task tracker has local directory,
<code> ${mapred.local.dir}/taskTracker/</code> to create localized