[ https://issues.apache.org/jira/browse/MAPREDUCE-2464?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Todd Lipcon resolved MAPREDUCE-2464. ------------------------------------ Resolution: Duplicate > NullPointerException is coming in the job tracker when job tracker resends > the previous heartbeat response. > ----------------------------------------------------------------------------------------------------------- > > Key: MAPREDUCE-2464 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-2464 > Project: Hadoop Map/Reduce > Issue Type: Bug > Components: jobtracker > Affects Versions: 0.23.0 > Reporter: Devaraj K > Assignee: Devaraj K > > Over the network, the heartbeat response sent by Job Tracker to Task Tracker > might get lost. When Task Tracker sends the old heart beat again to Job > Tracker then Job Tracker finds and ignores it saying duplicate and resends > the old heartbeat response which it is maintaining in a map. If the response > contains LaunchTaskAction for MapTask, then the NullPointerException is > throwing. > {code:xml} > 2011-05-02 16:01:53,148 INFO org.apache.hadoop.ipc.Server: IPC Server handler > 1 on 9001 caught: java.lang.NullPointerException > at org.apache.hadoop.mapred.MapTask.write(MapTask.java:140) > at > org.apache.hadoop.mapred.LaunchTaskAction.write(LaunchTaskAction.java:48) > at > org.apache.hadoop.mapred.HeartbeatResponse.write(HeartbeatResponse.java:91) > at > org.apache.hadoop.io.ObjectWritable.writeObject(ObjectWritable.java:163) > at org.apache.hadoop.io.ObjectWritable.write(ObjectWritable.java:74) > at org.apache.hadoop.ipc.Server.setupResponse(Server.java:1561) > at org.apache.hadoop.ipc.Server.access$2800(Server.java:96) > at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1433) > {code} -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira