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  1. Pig
  2. PIG-5385

Skip calling extra gc() before spilling large bag when unnecessary

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    Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Trivial
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.18.0
    • Component/s: None
    • Labels:
      None
    • Hadoop Flags:
      Reviewed

      Description

      In order to determine when to start spilling bags, Pig uses MemoryNotification for both MEMORY_THRESHOLD_EXCEEDED and MEMORY_COLLECTION_THRESHOLD_EXCEEDED.
      https://docs.oracle.com/javase/8/docs/api/java/lang/management/MemoryNotificationInfo.html

      Since spilling a large bag is expensive, Pig explicitly call System.gc() when the expected size is huge. I think we can skip this step when notification is based on MEMORY_COLLECTION_THRESHOLD_EXCEEDED since this means jvm has called the gc already.

        Attachments

        1. pig-5385-v01.patch
          1 kB
          Koji Noguchi

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            • Assignee:
              knoguchi Koji Noguchi
              Reporter:
              knoguchi Koji Noguchi
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              Dates

              • Created:
                Updated:
                Resolved: