[ https://issues.apache.org/jira/browse/MAPREDUCE-4502?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13455842#comment-13455842 ]
Tsuyoshi OZAWA commented on MAPREDUCE-4502: ------------------------------------------- s/Do you have some result to/Do you have any results about the benchmark?/ > Multi-level aggregation with combining the result of maps per node/rack > ----------------------------------------------------------------------- > > Key: MAPREDUCE-4502 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-4502 > Project: Hadoop Map/Reduce > Issue Type: Improvement > Components: applicationmaster, mrv2 > Reporter: Tsuyoshi OZAWA > Assignee: Tsuyoshi OZAWA > Attachments: speculative_draft.pdf > > > The shuffle costs is expensive in Hadoop in spite of the existence of > combiner, because the scope of combining is limited within only one MapTask. > To solve this problem, it's a good way to aggregate the result of maps per > node/rack by launch combiner. > This JIRA is to implement the multi-level aggregation infrastructure, > including combining per container(MAPREDUCE-3902 is related), coordinating > containers by application master without breaking fault tolerance of jobs. -- 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