[
https://issues.apache.org/jira/browse/MAPREDUCE-1568?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12860130#action_12860130
]
Amareshwari Sriramadasu commented on MAPREDUCE-1568:
----------------------------------------------------
I propose we should remove the deletion call from getLocalCache() itself. There
should be a separate cleanup thread in TrackerDistributedCacheManager which
monitors the disk space and starts deleting whenever disk goes high or number
of subdirs increase.
I don't think starting a thread for each deletion (currently done in the patch)
is scalable, there could be race for deletion if two threads started by two
getLocalCache() calls starts deleteCache().
Thoughts?
> TrackerDistributedCacheManager should do deleteLocalPath asynchronously
> -----------------------------------------------------------------------
>
> Key: MAPREDUCE-1568
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-1568
> Project: Hadoop Map/Reduce
> Issue Type: Improvement
> Affects Versions: 0.22.0
> Reporter: Scott Chen
> Assignee: Scott Chen
> Fix For: 0.22.0
>
> Attachments: MAPREDUCE-1568.txt
>
>
> TrackerDistributedCacheManager.deleteCache() has been improved:
> MAPREDUCE-1302 makes TrackerDistributedCacheManager rename the caches in the
> main thread and then delete them in the background
> MAPREDUCE-1098 avoids global locking while do the renaming (renaming lots of
> directories can also takes a long time)
> But the deleteLocalCache is still in the main thread of TaskRunner.run(). So
> it will still slow down the task which triggers the deletion (originally this
> will blocks all tasks, but it is fixed by MAPREDUCE-1098). Other tasks do not
> wait for the deletion. The task which triggers the deletion should not wait
> for this either. TrackerDistributedCacheManager should do deleteLocalPath()
> asynchronously.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
