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  1. Hadoop Common
  2. HADOOP-137

Different TaskTrackers may get the same task tracker id, thus cause many problems.

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Critical
    • Resolution: Fixed
    • Affects Version/s: 0.2.0
    • Fix Version/s: 0.2.0
    • Component/s: None
    • Labels:
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      Description

      In the TaskTracker#Initialize method, the following line assigns task tracker name (id):

      this.taskTrackerName = "tracker_" + (Math.abs(r.nextInt()) % 100000);

      For a fair size cluster, it is possible that different task trackers to get the same id, causing name conflict.
      I encountered this problem with a cluster of 274 nodes. Once such conflict happens, a lot of strange things may happen.
      For example, a reducer task tried to copy from a machine (task tracker) a map output file that was actually produced
      on another machine.

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              • Assignee:
                omalley Owen O'Malley
                Reporter:
                runping Runping Qi
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                • Created:
                  Updated:
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