hadoop-mapreduce-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Arun C Murthy (JIRA)" <j...@apache.org>
Subject [jira] [Closed] (MAPREDUCE-4301) Dedupe some strings in MRAM for memory savings
Date Thu, 11 Oct 2012 17:50:36 GMT

     [ https://issues.apache.org/jira/browse/MAPREDUCE-4301?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Arun C Murthy closed MAPREDUCE-4301.
------------------------------------

    
> Dedupe some strings in MRAM for memory savings
> ----------------------------------------------
>
>                 Key: MAPREDUCE-4301
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4301
>             Project: Hadoop Map/Reduce
>          Issue Type: Improvement
>          Components: applicationmaster
>    Affects Versions: 0.23.3, 2.0.0-alpha
>            Reporter: Robert Joseph Evans
>            Assignee: Robert Joseph Evans
>             Fix For: 0.23.3, 2.0.2-alpha
>
>         Attachments: MR-4301.txt
>
>
> Recently an OutOfMemoryError caused one of our jobs to become a zombie (MAPREDUCE-4300).
 It was a rather large job with 78000+ map tasks and only 750MB of heap configured.  I took
a heap dump to see if there were any obvious memory leaks, and I could not find any, but yourkit
and some digging found some potential memory optimizations that we could do.
> In this particular case we could save about 20MB if SplitMetaInfoReader.readSplitMetaInfo
only computed the JobSplitFile once instead of for each split. (a 2 line change)
> I will look into some others and see if there are more savings I can come up with.

--
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

Mime
View raw message