[
https://issues.apache.org/jira/browse/HADOOP-15548?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16528211#comment-16528211
]
Eric Payne commented on HADOOP-15548:
-------------------------------------
The precommit build failure is my fault. I should have waited for the precommit
build to run before I committed the branch-2 patch. Sorry about that.
I've committed it to trunk, branch-3.1, branch-3.0, branch-2, branch-2.9, and
branch-2.8
> Randomize local dirs
> --------------------
>
> Key: HADOOP-15548
> URL: https://issues.apache.org/jira/browse/HADOOP-15548
> Project: Hadoop Common
> Issue Type: Bug
> Reporter: Jim Brennan
> Assignee: Jim Brennan
> Priority: Minor
> Attachments: HADOOP-15548-branch-2.001.patch, HADOOP-15548.001.patch,
> HADOOP-15548.002.patch
>
>
> shuffle LOCAL_DIRS, LOG_DIRS and LOCAL_USER_DIRS when launching container.
> Some applications will process these in exactly the same way in every
> container (e.g. roundrobin) which can cause disks to get unnecessarily
> overloaded (e.g. one output file written to first entry specified in the
> environment variable).
> There are two paths for local dir allocation, depending on whether the size
> is unknown or known. The unknown path already uses a random algorithm. The
> known path initializes with a random starting point, and then goes
> round-robin after that. When selecting a dir, it increments the last used by
> one and then checks sequentially until it finds a dir that satisfies the
> request. Proposal is to increment by a random value of between 1 and
> num_dirs - 1, and then check sequentially from there. This should result in
> a more random selection in all cases.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
