[
https://issues.apache.org/jira/browse/HBASE-11562?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14070302#comment-14070302
]
Nick Dimiduk commented on HBASE-11562:
--------------------------------------
This sounds like a useful detail. Make it the default behavior? In practice,
shouldn't a well balanced table have fairly random region -> RegionServer
distribution? You see logically adjacent regions piling up on the same RS?
> CopyTable should provide an option to shuffle the mapper tasks
> --------------------------------------------------------------
>
> Key: HBASE-11562
> URL: https://issues.apache.org/jira/browse/HBASE-11562
> Project: HBase
> Issue Type: Bug
> Components: mapreduce
> Affects Versions: 0.99.0, 0.94.20, 0.98.4
> Reporter: Jean-Marc Spaggiari
> Assignee: Jean-Marc Spaggiari
> Attachments: HBASE-11562-v0-trunk.patch, HBASE-11562-v1-trunk.patch
>
>
> When doing a copy table from a table with a lot of regions to a table to way
> less regions, on a cluster with limited number of mappers, since map tasks
> are ordered by key, tasks will first run for the few first regions and will
> hotspot a single region server on the destination side.
> To avoid this, we should submit the map tasks in a random order.
> This JIRA is to add this option to CopyTable and TableInputFormat
--
This message was sent by Atlassian JIRA
(v6.2#6252)
