-Re: Hadoop Map Reduce Problem - Reduce failing
Arun C Murthy 2013-04-11, 07:14
Moving to user@.
What version of Hadoop are you running?
On Apr 10, 2013, at 6:57 PM, Farrokh Shahriari wrote:
> 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?
Arun C. Murthy