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  1. Hadoop Map/Reduce
  2. MAPREDUCE-6795

Update the document for JobConf#setNumReduceTasks

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    Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 2.8.0, 3.0.0-alpha2
    • Component/s: documentation
    • Labels:
      None
    • Hadoop Flags:
      Reviewed

      Description

      The following document is for MRv1. We should update the document for MapReduce on YARN.

      JobConf.java
         * <b id="NoOfReduces">How many reduces?</b>
   * 
   * <p>The right number of reduces seems to be <code>0.95</code> or 
   * <code>1.75</code> multiplied by (&lt;<i>no. of nodes</i>&gt; * 
   * <a href="{@docRoot}/../mapred-default.html#mapreduce.tasktracker.reduce.tasks.maximum">
   * mapreduce.tasktracker.reduce.tasks.maximum</a>).
   * </p>

        Attachments

        1. MAPREDUCE-6795.001.patch
          1 kB
          Yiqun Lin
        2. MAPREDUCE-6795.002.patch
          2 kB
          Yiqun Lin

          Issue Links

          is related to

          Sub-task - The sub-task of the issue MAPREDUCE-6794 Remove unused properties from TTConfig.java

          • Major - Major loss of function.
          • Resolved

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              People

              • Assignee:
                linyiqun Yiqun Lin
                Reporter:
                aajisaka Akira Ajisaka
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                Dates

                • Created:
                  Updated:
                  Resolved: