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Posted to mapreduce-issues@hadoop.apache.org by "Hadoop QA (JIRA)" <ji...@apache.org> on 2013/07/17 12:17:01 UTC

[jira] [Commented] (MAPREDUCE-4502) Node-level aggregation with combining the result of maps

    [ https://issues.apache.org/jira/browse/MAPREDUCE-4502?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13710921#comment-13710921 ] 

Hadoop QA commented on MAPREDUCE-4502:
--------------------------------------

{color:red}-1 overall{color}.  Here are the results of testing the latest attachment 
  http://issues.apache.org/jira/secure/attachment/12592745/MAPREDUCE-4502.9.patch
  against trunk revision .

    {color:green}+1 @author{color}.  The patch does not contain any @author tags.

    {color:green}+1 tests included{color}.  The patch appears to include 10 new or modified test files.

    {color:red}-1 javac{color:red}.  The patch appears to cause the build to fail.

Console output: https://builds.apache.org/job/PreCommit-MAPREDUCE-Build/3858//console

This message is automatically generated.
                
> Node-level aggregation with combining the result of maps
> --------------------------------------------------------
>
>                 Key: MAPREDUCE-4502
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4502
>             Project: Hadoop Map/Reduce
>          Issue Type: Improvement
>          Components: applicationmaster, mrv2
>    Affects Versions: 3.0.0
>            Reporter: Tsuyoshi OZAWA
>            Assignee: Tsuyoshi OZAWA
>         Attachments: design_v2.pdf, design_v3.pdf, MAPREDUCE-4502.1.patch, MAPREDUCE-4502.2.patch, MAPREDUCE-4502.3.patch, MAPREDUCE-4502.4.patch, MAPREDUCE-4502.5.patch, MAPREDUCE-4502.6.patch, MAPREDUCE-4502.7.patch, MAPREDUCE-4502.8.patch, MAPREDUCE-4502.8.patch, MAPREDUCE-4502.9.patch, MAPREDUCE-4525-pof.diff, 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.

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