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  1. Hadoop Map/Reduce
  2. MAPREDUCE-754

NPE in expiry thread when a TT is lost

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Details

    • Bug
    • Status: Closed
    • Minor
    • Resolution: Fixed
    • 0.20.1
    • 0.21.0
    • jobtracker
    • None
    • Reviewed
    • Hide
      Fixes the NPE in 'refreshNodes', ExpiryTracker thread and heartbeat. NPE occurred in the following cases
      - a blacklisted tracker is either decommissioned or expires.
      - a lost tracker gets blacklisted


      Show
      Fixes the NPE in 'refreshNodes', ExpiryTracker thread and heartbeat. NPE occurred in the following cases - a blacklisted tracker is either decommissioned or expires. - a lost tracker gets blacklisted

    Description

      NullPointerException is obtained in Tracker Expiry Thread. Below is the exception obtained in the JT logs 

      ERROR org.apache.hadoop.mapred.JobTracker: Tracker Expiry Thread got exception: java.lang.NullPointerException
        at org.apache.hadoop.mapred.JobTracker.updateTaskTrackerStatus(JobTracker.java:2971)
        at org.apache.hadoop.mapred.JobTracker.access$300(JobTracker.java:104)
        at org.apache.hadoop.mapred.JobTracker$ExpireTrackers.run(JobTracker.java:381)
        at java.lang.Thread.run(Thread.java:619)

      The steps to reproduce this issue are:

      • Blacklist a TT.
      • Restart it.
      • The above exception is obtained when the first instance of TT is marked as lost.

      However the above exception does not break any functionality.

      Attachments

        1. mapreduce-754-wip.patch
          13 kB
          Sreekanth Ramakrishnan
        2. mapreduce-754-v2.2-yahoo.patch
          22 kB
          Amar Kamat
        3. mapreduce-754-v2.2-branch-21.patch
          15 kB
          Amar Kamat
        4. mapreduce-754-v2.2.patch
          14 kB
          Amar Kamat
        5. mapreduce-754-v2.2.1-yahoo.patch
          10 kB
          Amar Kamat
        6. mapreduce-754-v1.2.patch
          14 kB
          Amar Kamat
        7. mapreduce-754-v1.1.patch
          10 kB
          Amar Kamat

        Issue Links

          is related to

          Bug - A problem which impairs or prevents the functions of the product. MAPREDUCE-1188 NPE in decommissioning blacklisted nodes

          • Major - Major loss of function.
          • Resolved

          Bug - A problem which impairs or prevents the functions of the product. MAPREDUCE-746 When a task tracker is killed, there is a Null Pointer exception thrown.

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          Activity

            People

              amar_kamat Amar Kamat
              rramya Ramya Sunil
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              Dates

                Created:
                Updated:
                Resolved: