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https://issues.apache.org/jira/browse/MAPREDUCE-2187?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13045475#comment-13045475
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Anupam Seth commented on MAPREDUCE-2187:
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As commented by Luke in MAPREDUCE-2177, the combiner code path doesn't report
progress at some configured interval, so it can timeout when map output is
large. A proposed fix is in CombineOutputCollector#collect to report progress a
la Merger#writeFile.
> map tasks timeout during sorting
> --------------------------------
>
> Key: MAPREDUCE-2187
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-2187
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Affects Versions: 0.20.2
> Reporter: Gianmarco De Francisci Morales
>
> During the execution of a large job, the map tasks timeout:
> {code}
> INFO mapred.JobClient: Task Id : attempt_201010290414_60974_m_000057_1,
> Status : FAILED
> Task attempt_201010290414_60974_m_000057_1 failed to report status for 609
> seconds. Killing!
> {code}
> The bug is in the fact that the mapper has already finished, and, according
> to the logs, the timeout occurs during the merge sort phase.
> The intermediate data generated by the map task is quite large. So I think
> this is the problem.
> The logs show that the merge-sort was running for 10 minutes when the task
> was killed.
> I think the mapred.Merger should call Reporter.progress() somewhere.
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