[MAPREDUCE-858] NPE in heartbeat if "mapred.job.tracker.history.completed.location" is not writable

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.20.1, 0.21.0
• Component/s: jobtracker
• Assignee: Unassigned
• Reporter: Ramya Sunil
• Created: 13/Aug/09 08:19
• Updated: 07/May/13 00:17
• Resolved: 07/May/13 00:17

Description

If "mapred.job.tracker.history.completed.location" has been configured to write to a location which is not writable by JT, NullPointerException is thrown in TT heartbeat. Below is the Exception obtained:

2009-08-13 07:56:02,815 INFO org.apache.hadoop.ipc.Server: IPC Server handler <handler> on <port>, call heartbeat(org.apache.hadoop.mapred.TaskTrackerStatus@1e7a6ae, false, false, true, 1775) from <ip>:<port>: error: java.io.IOException: java.lang.NullPointerException
java.io.IOException: java.lang.NullPointerException
        at org.apache.hadoop.mapred.JobHistory$JobHistoryFilesManager.moveToDone(JobHistory.java:215)
        at org.apache.hadoop.mapred.JobHistory$JobInfo.markCompleted(JobHistory.java:1071)
        at org.apache.hadoop.mapred.JobTracker.finalizeJob(JobTracker.java:2413)
        at org.apache.hadoop.mapred.JobInProgress.garbageCollect(JobInProgress.java:2729)
        at org.apache.hadoop.mapred.JobInProgress.jobComplete(JobInProgress.java:2327)
        at org.apache.hadoop.mapred.JobInProgress.completedTask(JobInProgress.java:2259)
        at org.apache.hadoop.mapred.JobInProgress.updateTaskStatus(JobInProgress.java:957)
        at org.apache.hadoop.mapred.JobTracker.updateTaskStatuses(JobTracker.java:3946)
        at org.apache.hadoop.mapred.JobTracker.processHeartbeat(JobTracker.java:3123)
        at org.apache.hadoop.mapred.JobTracker.heartbeat(JobTracker.java:2861)
        at sun.reflect.GeneratedMethodAccessor7.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:508)
        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:959)
        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:955)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:396)
        at org.apache.hadoop.ipc.Server$Handler.run(Server.java:953)

Instead of an NPE, it would be helpful if an useful error message is logged.