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  1. Hadoop Map/Reduce
  2. MAPREDUCE-5352

Optimize node local splits generated by CombineFileInputFormat

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Details

    • Improvement
    • Status: Closed
    • Major
    • Resolution: Fixed
    • 2.0.5-alpha
    • 2.1.0-beta
    • None
    • None
    • Reviewed

    Description

      CombineFileInputFormat currently walks through all available nodes and generates multiple (maxSplitsPerNode) splits on a single node before attempting to generate splits on subsequent nodes. This ends up reducing the possibility of generating splits for subsequent nodes - since these blocks will no longer be available for subsequent nodes. Allowing splits to go 1 block above the max-split-size makes this worse.
      Allocating a single split per node in one iteration, should help increase the distribution of splits across nodes - so the subsequent nodes will have more blocks to choose from.

      Attachments

        1. MAPREDUCE-5352.1.txt
          14 kB
          Siddharth Seth
        2. MAPREDUCE-5352.2.txt
          15 kB
          Siddharth Seth
        3. MAPREDUCE-5352.3.txt
          17 kB
          Siddharth Seth
        4. MAPREDUCE-5352.4.txt
          19 kB
          Siddharth Seth
        5. MAPREDUCE-5352.4.branch-2.1-beta.txt
          19 kB
          Siddharth Seth

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            sseth Siddharth Seth
            sseth Siddharth Seth
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              Updated:
              Resolved:

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