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From Arun C Murthy <...@hortonworks.com>
Subject Re: Hadoop Map Reduce Problem - Reduce failing
Date Thu, 11 Apr 2013 07:14:48 GMT
Moving to user@.

What version of Hadoop are you running?

On Apr 10, 2013, at 6:57 PM, Farrokh Shahriari wrote:

> Hello,
> 
> I've having a problem running my map/reduce job on my cluster. The map phase, completes
successfully, but the reduce phase fails with the following error message:
> 
> Error: java.lang.NullPointerException
> 	at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:768)
> 	at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.getMapCompletionEvents(ReduceTask.java:2835)
> 	at org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.run(ReduceTask.java:2756)
> 
> I've done a lot of searching, and I've found some solutions as to not having
> any underscores in my hosts names. I changed them all, but the problem still 
> 
> 
> hasn't resolved.
> Does anyone have any idea what the problem can be?
> 
> Thanks,
> Farrokh
> 

--
Arun C. Murthy
Hortonworks Inc.
http://hortonworks.com/



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