[
https://issues.apache.org/jira/browse/HADOOP-4749?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12654333#action_12654333
]
Zheng Shao commented on HADOOP-4749:
------------------------------------
Thanks for the patch.
I think we can ignore the case that mapper is local, because load balance
problem would not be interesting in that case.
Several suggestions:
1. Please use a new variable instead of moving bytesTransferred to class member
level. There are other places that referenced bytesTransferred.
2. Make the patch into a single file (svn diff in the trunk directory);
3. Please click on "Submit patch" after "Attach file" is done;
> reducer should output input data size when shuffling is done
> ------------------------------------------------------------
>
> Key: HADOOP-4749
> URL: https://issues.apache.org/jira/browse/HADOOP-4749
> Project: Hadoop Core
> Issue Type: Improvement
> Components: mapred
> Reporter: Zheng Shao
> Attachments: ReduceTask.patch, Task.patch
>
>
> Sometimes we see a single slow reducer because of the load balancing problem.
> This information will be very useful to understand how imbalanced the load is.
> Should be easy to fix I guess, since reducer should have all information
> needed at the end of the shuffling phase.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
