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Hudson commented on MAPREDUCE-3252: ----------------------------------- Integrated in Hadoop-Common-trunk-Commit #1148 (See [https://builds.apache.org/job/Hadoop-Common-trunk-Commit/1148/]) MAPREDUCE-3252. Fix map tasks to not rewrite data an extra time when map output fits in spill buffer. Contributed by Todd Lipcon. todd : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1188424 Files : * /hadoop/common/trunk/hadoop-mapreduce-project/CHANGES.txt * /hadoop/common/trunk/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/MapTask.java > MR2: Map tasks rewrite data once even if output fits in sort buffer > ------------------------------------------------------------------- > > Key: MAPREDUCE-3252 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-3252 > Project: Hadoop Map/Reduce > Issue Type: Bug > Components: mrv2, task > Affects Versions: 0.23.0 > Reporter: Todd Lipcon > Assignee: Todd Lipcon > Priority: Critical > Fix For: 0.23.0 > > Attachments: mr-3252.txt, mr-3252.txt > > > I found that, even if the output of a map task fits entirely in its sort > buffer, it was rewriting the output entirely rather than just renaming the > first spill into place. This is due to RawLocalFileSystem.rename() falling > back to a copy if renameTo() fails. The first rename attempt was failing > because no one has called mkdir for the output directory yet. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira