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https://issues.apache.org/jira/browse/MAPREDUCE-3944?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13220378#comment-13220378
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Robert Joseph Evans commented on MAPREDUCE-3944:
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I agree with Tom on this. I would also like to be able to limit the total
number of entries that can be returned, but we have the issue with ordering
here like Sid said. I am going to try to set up a stress test for this so I
can try out several fixes to see what happens. There are really two different
goals to this JIRA. The most important one is that even if someone is hitting
the web service a lot, the history server should still be usable. The second
part is to optimize the web service calls so that they reduce the load on the
system. I think that the locking is the primary thing for fixing the first
part, and I will put in the filtering changes too. Once I have those working I
will do some profiling and see what else looks like hot spots.
> JobHistory web services are slower then the UI and can easly overload the JH
> ----------------------------------------------------------------------------
>
> Key: MAPREDUCE-3944
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-3944
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: mrv2
> Affects Versions: 0.23.1, 0.23.2
> Reporter: Robert Joseph Evans
> Assignee: Robert Joseph Evans
> Priority: Blocker
>
> When our first customer started using the Job History web services today the
> History Server ground to a halt. We found 250 Jetty threads stuck on the
> following stack trace.
> {noformat}
> java.lang.Thread.State: BLOCKED (on object monitor)
> at
> org.apache.hadoop.mapreduce.v2.hs.JobHistory.getJob(JobHistory.java:898)
> - waiting to lock <0x00002aaab364ba60> (a
> org.apache.hadoop.mapreduce.v2.hs.JobHistory)
> at
> org.apache.hadoop.mapreduce.v2.hs.webapp.HsWebServices.getJobs(HsWebServices.java:188)
> {noformat}
> HsWebServices.java:188 corresponds to the /mapreduce/jobs service.
> Looking at the code there are a number of optimizations that need to be done
> to improve its performance.
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