hadoop-mapreduce-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Todd Lipcon (Resolved) (JIRA)" <j...@apache.org>
Subject [jira] [Resolved] (MAPREDUCE-2905) CapBasedLoadManager incorrectly allows assignment when assignMultiple is true (was: assignmultiple per job)
Date Tue, 22 Nov 2011 19:36:40 GMT

     [ https://issues.apache.org/jira/browse/MAPREDUCE-2905?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Todd Lipcon resolved MAPREDUCE-2905.
------------------------------------

       Resolution: Fixed
    Fix Version/s: 0.20.206.0
     Hadoop Flags: Reviewed

Committed to 0.20-security.
                
> CapBasedLoadManager incorrectly allows assignment when assignMultiple is true (was: assignmultiple
per job)
> -----------------------------------------------------------------------------------------------------------
>
>                 Key: MAPREDUCE-2905
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-2905
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>          Components: contrib/fair-share
>    Affects Versions: 0.20.2
>            Reporter: Jeff Bean
>            Assignee: Jeff Bean
>             Fix For: 0.20.206.0
>
>         Attachments: MR-2905.10-13-2011, MR-2905.patch, MR-2905.patch.2, mr-2905.txt,
mr-2905.txt, screenshot-1.jpg
>
>
> We encountered a situation where in the same cluster, large jobs benefit from mapred.fairscheduler.assignmultiple,
but small jobs with small numbers of mappers do not: the mappers all clump to fully occupy
just a few nodes, which causes those nodes to saturate and bottleneck. The desired behavior
is to spread the job across more nodes so that a relatively small job doesn't saturate any
node in the cluster.
> Testing has shown that setting mapred.fairscheduler.assignmultiple to false gives the
desired behavior for small jobs, but is unnecessary for large jobs. However, since this is
a cluster-wide setting, we can't properly tune.
> It'd be nice if jobs can set a param similar to mapred.fairscheduler.assignmultiple on
submission to better control the task distribution of a particular job.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message