You are viewing a plain text version of this content. The canonical link for it is here.

Posted to mapreduce-dev@hadoop.apache.org by "Siddharth Seth (JIRA)" <ji...@apache.org> on 2013/06/25 06:48:20 UTC

[jira] [Created] (MAPREDUCE-5352) Optimize node local splits generated by CombineFileInputFormat

Siddharth Seth created MAPREDUCE-5352:
-----------------------------------------

             Summary: Optimize node local splits generated by CombineFileInputFormat 
                 Key: MAPREDUCE-5352
                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-5352
             Project: Hadoop Map/Reduce
          Issue Type: Improvement
    Affects Versions: 2.0.5-alpha
            Reporter: Siddharth Seth
            Assignee: Siddharth Seth


CombineFileInputFormat currently walks through all available nodes and generates multiple (maxSplitsPerNode) splits on a single node before attempting to generate splits on subsequent nodes. This ends up reducing the possibility of generating splits for subsequent nodes - since these blocks will no longer be available for subsequent nodes. Allowing splits to go 1 block above the max-split-size makes this worse.
Allocating a single split per node in one iteration, should help increase the distribution of splits across nodes - so the subsequent nodes will have more blocks to choose from.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira