hadoop-mapreduce-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Konstantin Boudnik (JIRA)" <j...@apache.org>
Subject [jira] [Reopened] (MAPREDUCE-5211) Reducer intermediate files can collide during merge
Date Thu, 30 May 2013 17:11:21 GMT

     [ https://issues.apache.org/jira/browse/MAPREDUCE-5211?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel

Konstantin Boudnik reopened MAPREDUCE-5211:

This needs to go into the next stabilization release of as well. Adding the label
to that effect and re-opening the ticket.
> Reducer intermediate files can collide during merge
> ---------------------------------------------------
>                 Key: MAPREDUCE-5211
>                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-5211
>             Project: Hadoop Map/Reduce
>          Issue Type: Bug
>          Components: mrv2
>    Affects Versions: 0.23.7
>            Reporter: Jason Lowe
>            Assignee: Jason Lowe
>            Priority: Blocker
>              Labels:
>             Fix For: 0.23.8
>         Attachments: MAPREDUCE-5211.branch-0.23.patch
> The OnDiskMerger.merge method constructs an output path that is not unique to a reduce
attempt, and as a result can result in a file collision with other reducers from the same
app that are running on the same node.  In addition the name of the output file is based on
MapOutput.toString which may not be unique in light of multi-pass merges on disk since the
mapId will be null and the basename ends up as "MapOutput(null, DISK)"

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

View raw message