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https://issues.apache.org/jira/browse/HADOOP-9?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12928463#action_12928463
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Paul Baclace commented on HADOOP-9:
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You're welcome, Owen! (I wrote the roulette selection patch.)
> mapred.local.dir temp dir. space allocation limited by smallest area
> ---------------------------------------------------------------------
>
> Key: HADOOP-9
> URL: https://issues.apache.org/jira/browse/HADOOP-9
> Project: Hadoop Common
> Issue Type: Bug
> Environment: all
> Reporter: Paul Baclace
> Assignee: Ari Rabkin
> Priority: Minor
> Fix For: 0.19.0
>
> Attachments: hadoop9.patch
>
>
> When mapred.local.dir is used to specify multiple temp dir. areas, space
> allocation limited by smallest area because the temp dir. selection algorithm
> is "round robin starting from a randomish point". When round robin is used
> with approximately constant sized chunks, the smallest area runs out of space
> first, and this is a fatal error.
> Workaround: only list local fs dirs in mapred.local.dir with similarly-sized
> available areas.
> I wrote a patch to JobConf (currenly being tested) which uses df to check
> available space (once a minute or less often) and then uses an efficient
> roulette selection to do allocation weighted by magnitude of available space.
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