Try running
"select count(1) from table;"
Thanks & Regards
~guru
On 09/28/2010 08:07 PM, vaibhav negi wrote:
Hi,
I am using hadoop version 0.20.2
While running query "select count(*) from table;" on Hive,i am getting
this error
FAILED: Execution Error, return code 2 from
org.apache.hadoop.hive.ql.exec.MapRedTask
Error in task tracker logs says :-
Error: java.lang.NullPointerException
at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:768)
at
org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.getMapCompletionEvents(ReduceTask.java:2683)
at
org.apache.hadoop.mapred.ReduceTask$ReduceCopier$GetMapEventsThread.run(ReduceTask.java:2605)
On debugging i found that ReduceTask.java:2683 line is using host
which is coming null
ReduceTask.java:2683 ---
List loc = mapLocations.get(host);
One user in Hadoop Forum says HADOOP-4744 should be included in
hadoop. Is this patch required for hadoop 0.20.2 ?
How to add patch?
Is this an issue with /etc/hosts file?
Please help
Regards
Vaibhav Negi
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