[
https://issues.apache.org/jira/browse/MAPREDUCE-4961?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Allen Wittenauer updated MAPREDUCE-4961:
----------------------------------------
Labels: BB2015-05-TBR (was: )
> 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
> Reporter: Jerry Chen
> Assignee: Jerry Chen
> Labels: BB2015-05-TBR
> Attachments: MAPREDUCE-4961.patch, MAPREDUCE-4961.patch
>
> 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 was sent by Atlassian JIRA
(v6.3.4#6332)
