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hbase-4898. book.xml (1 correction in no-reducer summary) 

troubleshooting.xml 1 addition for MapReduce related documentation.

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1208230 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Doug Meil 2011-11-30 03:08:14 +00:00
parent a0cce57e46
commit d11ddc0622
2 changed files with 10 additions and 3 deletions
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8
src/docbkx/book.xml
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@ -867,9 +867,11 @@ System.out.println("md5 digest as string length: " + sbDigest.length); // ret
<chapter xml:id="mapreduce">
<title>HBase and MapReduce</title>
<para>See <link xlink:href="http://hbase.org/apidocs/org/apache/hadoop/hbase/mapreduce/package-summary.html#package_description">HBase and MapReduce</link> up in javadocs.
<para>See <link xlink:href="http://hbase.org/apidocs/org/apache/hadoop/hbase/mapreduce/package-summary.html#package_description">
HBase and MapReduce</link> up in javadocs.
Start there. Below is some additional help.</para>
<para>For more information about MapReduce, see the <link xlink:href="http://hadoop.apache.org/common/docs/current/mapred_tutorial.html">Hadoop MapReduce Tutorial</link>.</para>
<para>For more information about MapReduce (i.e., the framework in general), see the
<link xlink:href="http://hadoop.apache.org/common/docs/current/mapred_tutorial.html">Hadoop MapReduce Tutorial</link>.</para>
<section xml:id="splitter">
<title>Map-Task Spitting</title>
<section xml:id="splitter.default">
@ -1117,7 +1119,7 @@ if (!b) {
<title>HBase MapReduce Summary Without Reducer</title>
<para>It is also possible to perform summaries without a reducer - if you use HBase as the reducer.
</para>
<para>There would need to exist an HTable target table for the job summary. The HTable method <code>incrementColumnValue</code>
<para>An HBase target table would need to exist for the job summary. The HTable method <code>incrementColumnValue</code>
would be used to atomically increment values. From a performance perspective, it might make sense to keep a Map
of values with their values to be incremeneted for each map-task, and make one update per key at during the <code>
cleanup</code> method of the mapper. However, your milage may vary depending on the number of rows to be processed and

5
src/docbkx/troubleshooting.xml
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@ -555,6 +555,11 @@ Caused by: java.io.FileNotFoundException: File _partition.lst does not exist.
</programlisting>
LocalJobRunner means the job is running locally, not on the cluster.
</para>
<para>See
<link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/mapreduce/package-summary.html#classpath">
http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/mapreduce/package-summary.html#classpath</link> for more
information on HBase MapReduce jobs and classpaths.
</para>
</section>
</section>