You are viewing a plain text version of this content. The canonical link for it is here.
Posted to mapreduce-issues@hadoop.apache.org by "Hudson (JIRA)" <ji...@apache.org> on 2011/04/07 17:42:19 UTC
[jira] [Commented] (MAPREDUCE-2167) Faster directory traversal for
raid node
[ https://issues.apache.org/jira/browse/MAPREDUCE-2167?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13016948#comment-13016948 ]
Hudson commented on MAPREDUCE-2167:
-----------------------------------
Integrated in Hadoop-Mapreduce-trunk #643 (See [https://hudson.apache.org/hudson/job/Hadoop-Mapreduce-trunk/643/])
> Faster directory traversal for raid node
> ----------------------------------------
>
> Key: MAPREDUCE-2167
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-2167
> Project: Hadoop Map/Reduce
> Issue Type: Improvement
> Components: contrib/raid
> Reporter: Ramkumar Vadali
> Assignee: Ramkumar Vadali
> Fix For: 0.22.0
>
> Attachments: MAPREDUCE-2167.2.patch, MAPREDUCE-2167.3.patch, MAPREDUCE-2167.4.patch, MAPREDUCE-2167.patch
>
>
> The RaidNode currently iterates over the directory structure to figure out which files to RAID. With millions of files, this can take a long time - especially if some files are already RAIDed and the RaidNode needs to look at parity files / parity file HARs to determine if the file needs to be RAIDed.
> The directory traversal is encapsulated inside the class DirectoryTraversal, which examines one file at a time, using the caller's thread.
> My proposal is to make this multi-threaded as follows:
> * use a pool of threads inside DirectoryTraversal
> * The caller's thread is used to retrieve directories, and each new directory is assigned to a thread in the pool. The worker thread examines all the files the directory.
> * If there sub-directories, those are added back as workitems to the pool.
> Comments?
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira