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Hudson commented on MAPREDUCE-5268: ----------------------------------- Integrated in Hadoop-trunk-Commit #3837 (See [https://builds.apache.org/job/Hadoop-trunk-Commit/3837/]) MAPREDUCE-5268. Improve history server startup performance. Contributed by Karthik Kambatla (Revision 1489012) Result = SUCCESS jlowe : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1489012 Files : * /hadoop/common/trunk/hadoop-mapreduce-project/CHANGES.txt * /hadoop/common/trunk/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/main/java/org/apache/hadoop/mapreduce/v2/hs/HistoryFileManager.java * /hadoop/common/trunk/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/test/java/org/apache/hadoop/mapreduce/v2/hs/TestJobIdHistoryFileInfoMap.java * /hadoop/common/trunk/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/test/java/org/apache/hadoop/mapreduce/v2/hs/TestJobListCache.java > Improve history server startup performance > ------------------------------------------ > > Key: MAPREDUCE-5268 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-5268 > Project: Hadoop Map/Reduce > Issue Type: Improvement > Components: jobhistoryserver > Affects Versions: 0.23.7, 2.0.4-alpha > Reporter: Jason Lowe > Assignee: Karthik Kambatla > Fix For: 2.1.0-beta, 0.23.9 > > Attachments: mr-5268.patch, mr-5268.patch, mr-5268.patch, > mr-5268.patch, mr-5268.patch, mr-5268-prelim.patch > > > The history server can easily take many minutes to startup when there are a > significant number of jobs to scan in the done directory. However the > scanning of files is not the bottleneck, rather it's the heavy use of > ConcurrentSkipListMap.size in HistoryFileManager. > ConcurrentSkipListMap.size is a very expensive operation, especially on maps > with many entries, as it has to scan every entry to compute the size. We > should avoid calling this method or at least minimize its use. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira