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  1. HBase
  2. HBASE-3587

Eliminate use of ReadWriteLock in RegionObserver coprocessor invocation

    Details

    • Type: Improvement
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.92.0
    • Component/s: Coprocessors
    • Labels:
      None

      Description

      Follow-up to a discussion on the dev list: http://search-hadoop.com/m/jOovV1uAJBP

      The CoprocessorHost ReentrantReadWriteLock is imposing some overhead on data read/write operations, even when no coprocessors are loaded. Currently execution of RegionCoprocessorHost pre/postXXX() methods are guarded by acquiring the coprocessor read lock. This is used to prevent coprocessor registration from modifying the coprocessor collection while upcall hooks are in progress.

      On further discussion, and looking at the locking in HRegion, it should be sufficient to just use a CopyOnWriteArrayList for the coprocessor collection. We can then remove the coprocessor lock and eliminate the associated overhead without having to special case the "no loaded coprocessors" condition.

        Attachments

        1. HBASE-3587.patch
          72 kB
          Gary Helmling

          Activity

            People

            • Assignee:
              ghelmling Gary Helmling
              Reporter:
              ghelmling Gary Helmling
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              Dates

              • Created:
                Updated:
                Resolved: