Hadoop Map/Reduce
  1. Hadoop Map/Reduce
  2. MAPREDUCE-1397

NullPointerException observed during task failures

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Minor Minor
    • Resolution: Fixed
    • Affects Version/s: 0.20.1
    • Fix Version/s: 0.21.0
    • Component/s: tasktracker
    • Labels:
      None
    • Hadoop Flags:
      Reviewed
    • Release Note:
      Fixed a race condition involving JvmRunner.kill() and KillTaskAction, which was leading to an NullPointerException causing a transient inconsistent state in JvmManager and failure of tasks.

      Description

      In an environment where many jobs are killed simultaneously, NPEs are observed in the TT/JT logs when a task fails. The situation is aggravated when the taskcontroller.cfg is not configured properly. Below is the exception obtained:

      INFO org.apache.hadoop.mapred.TaskInProgress: Error from <attempt_ID>:
      java.lang.Throwable: Child Error
              at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:529)
      Caused by: java.lang.NullPointerException
              at org.apache.hadoop.mapred.JvmManager$JvmManagerForType.getDetails(JvmManager.java:329)
              at org.apache.hadoop.mapred.JvmManager$JvmManagerForType.reapJvm(JvmManager.java:315)
              at org.apache.hadoop.mapred.JvmManager$JvmManagerForType.access$000(JvmManager.java:146)
              at org.apache.hadoop.mapred.JvmManager.launchJvm(JvmManager.java:109)
              at org.apache.hadoop.mapred.TaskRunner.run(TaskRunner.java:502)
      
       
      1. ASF.LICENSE.NOT.GRANTED--patch-1397-2.txt
        11 kB
        Amareshwari Sriramadasu
      2. patch-1397.txt
        10 kB
        Amareshwari Sriramadasu
      3. patch-1397-1.txt
        11 kB
        Amareshwari Sriramadasu
      4. patch-1397-3.txt
        13 kB
        Amareshwari Sriramadasu
      5. patch-1397-ydist.txt
        13 kB
        Amareshwari Sriramadasu

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            • Assignee:
              Amareshwari Sriramadasu
              Reporter:
              Ramya Sunil
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              Dates

              • Created:
                Updated:
                Resolved:

                Development