You are viewing a plain text version of this content. The canonical link for it is here.
Posted to mapreduce-issues@hadoop.apache.org by "Jerry Chen (JIRA)" <ji...@apache.org> on 2013/01/26 03:57:14 UTC
[jira] [Assigned] (MAPREDUCE-4961) Map reduce running local should
also go through ShuffleConsumerPlugin for enabling different MergeManager
implementations
[ https://issues.apache.org/jira/browse/MAPREDUCE-4961?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jerry Chen reassigned MAPREDUCE-4961:
-------------------------------------
Assignee: Jerry Chen
> Map reduce running local should also go through ShuffleConsumerPlugin for enabling different MergeManager implementations
> -------------------------------------------------------------------------------------------------------------------------
>
> Key: MAPREDUCE-4961
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-4961
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Affects Versions: trunk
> Reporter: Jerry Chen
> Assignee: Jerry Chen
> Original Estimate: 72h
> Remaining Estimate: 72h
>
> MAPREDUCE-4049 provide the ability for pluggable Shuffle and MAPREDUCE-4080 extends Shuffle to be able to provide different MergeManager implementations.
> While using these pluggable features, I find that when a map reduce is running locally, a RawKeyValueIterator was returned directly from a static call of Merge.merge, which break the assumption that the Shuffle may provide different merge methods although there is no copy phase for this situation.
> The use case is when I am implementating a hash-based MergeManager, we don't need sort in map side, while when running the map reduce locally, the hash-based MergeManager will have no chance to be used as it goes directly to Merger.merge. This makes the pluggable Shuffle and MergeManager incomplete.
> So we need to move the code calling Merger.merge from Reduce Task to ShuffleConsumerPlugin implementation, so that the Suffle implementation can decide how to do the merge and return corresponding iterator.
--
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