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
