Hadoop Map/Reduce
  1. Hadoop Map/Reduce
  2. MAPREDUCE-1089

Fair Scheduler preemption triggers NPE when tasks are scheduled but not running

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: 0.21.0
    • Fix Version/s: 0.21.0
    • Component/s: contrib/fair-share
    • Labels:
      None
    • Hadoop Flags:
      Reviewed

      Description

      We see exceptions like this when preemption runs when a task has been scheduled on a TT but has not yet started running.

      2009-10-09 14:30:53,989 INFO org.apache.hadoop.mapred.FairScheduler: Should preempt 2 MAP tasks for job_200910091420_0006: tasksDueToMinShare = 2, tasksDueToFairShare = 0
      2009-10-09 14:30:54,036 ERROR org.apache.hadoop.mapred.FairScheduler: Exception in fair scheduler UpdateThread
      java.lang.NullPointerException
      at org.apache.hadoop.mapred.FairScheduler$2.compare(FairScheduler.java:1015)
      at org.apache.hadoop.mapred.FairScheduler$2.compare(FairScheduler.java:1013)
      at java.util.Arrays.mergeSort(Arrays.java:1270)
      at java.util.Arrays.sort(Arrays.java:1210)
      at java.util.Collections.sort(Collections.java:159)
      at org.apache.hadoop.mapred.FairScheduler.preemptTasks(FairScheduler.java:1013)
      at org.apache.hadoop.mapred.FairScheduler.preemptTasksIfNecessary(FairScheduler.java:911)
      at org.apache.hadoop.mapred.FairScheduler$UpdateThread.run(FairScheduler.java:286)

        Activity

          People

          • Assignee:
            Todd Lipcon
            Reporter:
            Todd Lipcon
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            Dates

            • Created:
              Updated:
              Resolved:

              Development