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Jay Finger commented on MAPREDUCE-3902: --------------------------------------- I haven't read the patch, forgive me if the answer is already there. Is there a cap on the amount of re-use? For example, if the container has been in use for more than 1 minute then do not re-use it. Or to rephrase, what prevents a cluster with a few large jobs from having hogged containers? > MR AM should reuse containers for map tasks > ------------------------------------------- > > Key: MAPREDUCE-3902 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-3902 > Project: Hadoop Map/Reduce > Issue Type: Improvement > Components: applicationmaster, mrv2 > Reporter: Arun C Murthy > Assignee: Arun C Murthy > Attachments: MAPREDUCE-3902.patch > > > The MR AM is now in a great position to reuse containers across (map) tasks. > This is something similar to JVM re-use we had in 0.20.x, but in a > significantly better manner: > # Consider data-locality when re-using containers > # Consider the new shuffle - ensure that reduces fetch output of the whole > container at once (i.e. all maps) -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira