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
