You are viewing a plain text version of this content. The canonical link for it is here.
Posted to mapreduce-dev@hadoop.apache.org by "Jason Lowe (JIRA)" <ji...@apache.org> on 2013/05/22 22:12:22 UTC
[jira] [Created] (MAPREDUCE-5268) Improve history server startup
performance
Jason Lowe created MAPREDUCE-5268:
-------------------------------------
Summary: 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: 2.0.4-alpha, 0.23.7
Reporter: Jason Lowe
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