Hi Forrest. Would you mind attaching an svn patch to fix this issue? Also, I will move this bug to the MAPREDUCE project, since it is MR-specific.

-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12481568/MAPREDUCE-2487.patch
against trunk revision 1132529.

+1 @author. The patch does not contain any @author tags.

+1 tests included. The patch appears to include 3 new or modified tests.

+1 javadoc. The javadoc tool did not generate any warning messages.

+1 javac. The applied patch does not increase the total number of javac compiler warnings.

-1 findbugs. The patch appears to introduce 1 new Findbugs (version 1.3.9) warnings.

+1 release audit. The applied patch does not increase the total number of release audit warnings.

-1 core tests. The patch failed these core unit tests:
org.apache.hadoop.cli.TestMRCLI
org.apache.hadoop.fs.TestFileSystem

+1 contrib tests. The patch passed contrib unit tests.

+1 system test framework. The patch passed system test framework compile.

Test results: https://builds.apache.org/hudson/job/PreCommit-MAPREDUCE-Build/350//testReport/
Findbugs warnings: https://builds.apache.org/hudson/job/PreCommit-MAPREDUCE-Build/350//artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Console output: https://builds.apache.org/hudson/job/PreCommit-MAPREDUCE-Build/350//console

This message is automatically generated.

Committed to 22 and trunk. Thanks Devaraj and Forrest.

Integrated in Hadoop-Mapreduce-trunk-Commit #716 (See https://builds.apache.org/hudson/job/Hadoop-Mapreduce-trunk-Commit/716/)
MAPREDUCE-2487. ChainReducer uses MAPPER_BY_VALUE instead of REDUCER_BY_VALUE. Contributed by Devaraj K.

todd : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1132719
Files :

• /hadoop/mapreduce/trunk/src/java/org/apache/hadoop/mapred/lib/Chain.java
• /hadoop/mapreduce/trunk/CHANGES.txt
• /hadoop/mapreduce/trunk/src/test/mapred/org/apache/hadoop/mapred/lib/TestChain.java

Integrated in Hadoop-Mapreduce-22-branch #58 (See https://builds.apache.org/job/Hadoop-Mapreduce-22-branch/58/)
MAPREDUCE-2487. Amend previous commit with the new test case (forgot to svn add)
MAPREDUCE-2487. ChainReducer uses MAPPER_BY_VALUE instead of REDUCER_BY_VALUE. Contributed by Devaraj K.

todd : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1132721
Files :

• /hadoop/mapreduce/branches/branch-0.22/src/test/mapred/org/apache/hadoop/mapred/lib/TestChain.java

todd : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1132720
Files :

• /hadoop/mapreduce/branches/branch-0.22/CHANGES.txt
• /hadoop/mapreduce/branches/branch-0.22/src/java/org/apache/hadoop/mapred/lib/Chain.java

Integrated in Hadoop-Mapreduce-trunk #722 (See https://builds.apache.org/job/Hadoop-Mapreduce-trunk/722/)