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  1. Hadoop Map/Reduce
  2. MAPREDUCE-6795

Update the document for JobConf#setNumReduceTasks

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

                Issue Links

                is related to

                Improvement - An improvement or enhancement to an existing feature or task. MAPREDUCE-6794 Remove unused properties from TTConfig.java

                • Major - Major loss of function.
                • Patch Available

                  Activity

                    People

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

                      • Created:
                        Updated:
                        Resolved: