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Siddharth Seth commented on MAPREDUCE-3902: ------------------------------------------- You're right. There's a lot of patches which will need to go in. Creating some of the sub-tasks that will be required before this can be considered for a merge back to trunk. I believe this will take several more weeks. MAPREDUCE-4502 doesn't necessarily need to be blocked on this - if that's something you're waiting to work on. > MR AM should reuse containers for map tasks, there-by allowing fine-grained > control on num-maps for users without need for CombineFileInputFormat etc. > ------------------------------------------------------------------------------------------------------------------------------------------------------ > > 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: Siddharth Seth > Attachments: MAPREDUCE-3902.2.patch, 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) : MAPREDUCE-4525 -- 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