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  1. Hadoop Common
  2. HADOOP-6133

ReflectionUtils performance regression

    Details

    • Type: Improvement
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 0.20.0
    • Fix Version/s: 0.21.0
    • Component/s: conf
    • Labels:
      None
    • Hadoop Flags:
      Reviewed

      Description

      HADOOP-4187 introduced extra calls to Class.forName in ReflectionUtils.setConf. This caused a fairly large performance regression. Attached is a microbenchmark that shows the following timings (ms) for 100M constructions of new instances:

      Explicit construction (new Test): around ~1.6sec
      Using Test.class.newInstance: around ~2.6sec
      ReflectionUtils on 0.18.3: ~8.0sec
      ReflectionUtils on 0.20.0: ~200sec

      This illustrates the ~80x slowdown caused by HADOOP-4187.

        Attachments

        1. Test.java
          2 kB
          Todd Lipcon
        2. hadoop-6133-trunk.txt
          2 kB
          Todd Lipcon
        3. hadoop-6133-trunk.txt
          2 kB
          Todd Lipcon
        4. hadoop-6133-0.20.patch
          2 kB
          Todd Lipcon

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              • Assignee:
                tlipcon Todd Lipcon
                Reporter:
                tlipcon Todd Lipcon
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                • Created:
                  Updated:
                  Resolved: