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https://issues.apache.org/jira/browse/MAPREDUCE-1342?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12796269#action_12796269
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Konstantin Boudnik commented on MAPREDUCE-1342:
-----------------------------------------------

I wonder if 
[JSure|http://wiki.apache.org/hadoop/HowToUseConcurrencyAnalysisTools] was able 
to find the issue? M.b. Chris wants to comment on this?

> Potential JT deadlock in faulty TT tracking
> -------------------------------------------
>
>                 Key: MAPREDUCE-1342
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-1342
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>          Components: jobtracker
>    Affects Versions: 0.22.0
>            Reporter: Todd Lipcon
>         Attachments: cycle0.png, mapreduce-1342-1.patch, 
> mapreduce-1342-2.patch
>
>
> JT$FaultyTrackersInfo.incrementFaults first locks potentiallyFaultyTrackers, 
> and then calls blackListTracker, which calls removeHostCapacity, which locks 
> JT.taskTrackers
> On the other hand, JT.blacklistedTaskTrackers() locks taskTrackers, then 
> calls faultyTrackers.isBlacklisted() which goes on to lock 
> potentiallyFaultyTrackers.
> I haven't produced such a deadlock, but the lock ordering here is inverted 
> and therefore could deadlock.
> Not sure if this goes back to 0.21 or just in trunk.

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