[jira] [Commented] (MAPREDUCE-5932) Provide an option to use a dedicated reduce-side shuffle log

["Hadoop QA (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/MAPREDUCE-5932?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14192846#comment-14192846 ] 

Hadoop QA commented on MAPREDUCE-5932:
--------------------------------------

{color:red}-1 overall{color}.  Here are the results of testing the latest attachment 
  http://issues.apache.org/jira/secure/attachment/12651193/MAPREDUCE-5932.v02.patch
  against trunk revision 86ff28d.

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

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

    {color:green}+1 javac{color}.  The applied patch does not increase the total number of javac compiler warnings.

    {color:green}+1 javadoc{color}.  There were no new javadoc warning messages.

    {color:green}+1 eclipse:eclipse{color}.  The patch built with eclipse:eclipse.

    {color:green}+1 findbugs{color}.  The patch does not introduce any new Findbugs (version 2.0.3) warnings.

    {color:green}+1 release audit{color}.  The applied patch does not increase the total number of release audit warnings.

    {color:red}-1 core tests{color}.  The test build failed in hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common 

    {color:green}+1 contrib tests{color}.  The patch passed contrib unit tests.

Test results: https://builds.apache.org/job/PreCommit-MAPREDUCE-Build/4990//testReport/
Console output: https://builds.apache.org/job/PreCommit-MAPREDUCE-Build/4990//console

This message is automatically generated.

> Provide an option to use a dedicated reduce-side shuffle log
> ------------------------------------------------------------
>
>                 Key: MAPREDUCE-5932
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-5932
>             Project: Hadoop Map/Reduce
>          Issue Type: Improvement
>          Components: mrv2
>    Affects Versions: 2.4.0
>            Reporter: Gera Shegalov
>            Assignee: Gera Shegalov
>         Attachments: MAPREDUCE-5932.v01.patch, MAPREDUCE-5932.v02.patch
>
>
> For reducers in large jobs our users cannot easily spot portions of the log associated with problems with their code. An example reducer with INFO-level logging generates ~3500 lines / ~700KiB  lines per second. 95% of the log is the client-side of the shuffle {{org.apache.hadoop.mapreduce.task.reduce.*}}
> {code}
> $ wc syslog 
>     3642   48192  691013 syslog
> $ grep task.reduce syslog | wc 
>     3424   46534  659038
> $ grep task.reduce.ShuffleScheduler syslog | wc 
>     1521   17745  251458
> $ grep task.reduce.Fetcher syslog | wc 
>     1045   15340  223683
> $ grep task.reduce.InMemoryMapOutput syslog | wc 
>      400    4800   72060
> $ grep task.reduce.MergeManagerImpl syslog | wc 
>      432    8200  106555
> {code}
> Byte percentage breakdown:
> {code}
> Shuffle total:           95%
> ShuffleScheduler:        36%
> Fetcher:                 32%
> InMemoryMapOutput:       10%
> MergeManagerImpl:        15%
> {code}
> While this is information is actually often useful for devops debugging shuffle performance issues, the job users are often lost. 
> We propose to have a dedicated syslog.shuffle file.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)