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  1. Hadoop Map/Reduce
  2. MAPREDUCE-1829

JobInProgress.findSpeculativeTask should use min() to find the candidate instead of sort()

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Details

    • Improvement
    • Status: Closed
    • Major
    • Resolution: Fixed
    • 0.22.0
    • 0.22.0
    • jobtracker
    • None
    • Reviewed
    • Improved performance of the method JobInProgress.findSpeculativeTask() which is in the critical heartbeat code path.

    Description

      findSpeculativeTask needs only one candidate to speculate so it does not need to sort the whole list. It may looks OK but someone can still submit big jobs with small slow task thresholds. In this case, this sorting becomes expensive.

      Attachments

        1. MAPREDUCE-1829.txt
          1 kB
          Scott Chen
        2. MAPREDUCE-1829-20100610.txt
          3 kB
          Vinod Kumar Vavilapalli

        Activity

          People

            schen Scott Chen
            schen Scott Chen
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            Dates

              Created:
              Updated:
              Resolved: