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] [Commented] (MAPREDUCE-199) Locality hints for Reduce
Date Mon, 10 Sep 2012 13:20:09 GMT

    [ https://issues.apache.org/jira/browse/MAPREDUCE-199?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13451952#comment-13451952
] 

Arun C Murthy commented on MAPREDUCE-199:
-----------------------------------------

I'm not sure I see the value in user-specifying 'hints', the way to get this to work is to
'figure' where the map-outputs are (the AM knows it) and then try to pick the right hosts/racks.


                
> Locality hints for Reduce
> -------------------------
>
>                 Key: MAPREDUCE-199
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-199
>             Project: Hadoop Map/Reduce
>          Issue Type: New Feature
>          Components: applicationmaster, mrv2
>            Reporter: Benjamin Reed
>            Assignee: Harsh J
>         Attachments: MAPREDUCE-199.patch, MAPREDUCE-199.patch
>
>
> It would be nice if we could add method to OutputFormat that would allow a job to indicate
where a reducer for a given partition should should run. This is similar to the getSplits()
method on InputFormat. In our application the reducer is using other data in addition to the
map outputs during processing and data accesses could be made more efficient if the JobTracker
scheduled the reducers to run on specific hosts.

--
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