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  1. Hadoop Map/Reduce
  2. MAPREDUCE-6795

Update the document for JobConf#setNumReduceTasks

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Details

    • Improvement
    • Status: Resolved
    • Major
    • Resolution: Fixed
    • None
    • 2.8.0, 3.0.0-alpha2
    • documentation
    • None
    • 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-6795.002.patch
          2 kB
          Yiqun Lin
        2. MAPREDUCE-6795.001.patch
          1 kB
          Yiqun Lin

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              linyiqun Yiqun Lin
              aajisaka Akira Ajisaka
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                Created:
                Updated:
                Resolved: