[ 
https://issues.apache.org/jira/browse/HADOOP-4620?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12653211#action_12653211
 ] 

Ravi Gummadi commented on HADOOP-4620:
--------------------------------------

The ideal behaviour could be to have the correct output in this case also(input 
is of 0 size for mapper/reducer and the task generates output).

Is it good enough that the mapper/reducer doesn't hang and finish execution in 
the case of 0 sized input(even though the output of the mapper/reducer is not 
available in intermediateFile/HDFS at the end of the task) ?

> Streaming mapper never completes if the mapper does not write to stdout
> -----------------------------------------------------------------------
>
>                 Key: HADOOP-4620
>                 URL: https://issues.apache.org/jira/browse/HADOOP-4620
>             Project: Hadoop Core
>          Issue Type: Bug
>          Components: mapred
>    Affects Versions: 0.17.2
>            Reporter: Runping Qi
>            Assignee: Ravi Gummadi
>
> A mapper of a streaming job has empty input data and thus it produces no 
> output.
> The task never completes.
> The following are the last two lines from the task log:
> 2008-11-07 21:59:48,254 INFO org.apache.hadoop.streaming.PipeMapRed: 
> PipeMapRed exec [/usr/bin/perl, xxx]
> 2008-11-07 21:59:48,330 INFO org.apache.hadoop.streaming.PipeMapRed: 
> mapRedFinished
>  

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to