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  1. ZooKeeper
  2. ZOOKEEPER-876

Unnecessary snapshot transfers between new leader and followers

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Details

    • Bug
    • Status: Resolved
    • Minor
    • Resolution: Fixed
    • 3.4.0
    • 3.5.0
    • None
    • None

    Description

      When starting a new leadership, unnecessary snapshot transfers happen between new leader and followers. This is so because of multiple small bugs.

      1) the comparison of zxids is done based on a new proposal, instead of the last logged zxid. (LearnerHandler.java ~ 297)
      2) if follower is one zxid behind, the check of the interval of committed logs excludes the follower. (LearnerHandler.java ~ 277)
      3) the bug reported in ZOOKEEPER-874 (commitLogs are empty after recover).

      Attachments

        1. second_case.patch
          5 kB
          Diogo
        2. second_case.txt
          31 kB
          Diogo
        3. TEST-org.apache.zookeeper.test.FollowerResyncConcurrencyTest.txt
          652 kB
          Flavio Paiva Junqueira
        4. ZOOKEEPER-876.patch
          9 kB
          Diogo

        Issue Links

          depends upon

          Bug - A problem which impairs or prevents the functions of the product. ZOOKEEPER-874 FileTxnSnapLog.restore does not call listener

          • Trivial - Cosmetic problem like misspelt words or misaligned text.
          • Closed
          Is contained by

          Improvement - An improvement or enhancement to an existing feature or task. ZOOKEEPER-1413 Use on-disk transaction log for learner sync up

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          Activity

            People

              dioog Diogo
              dioog Diogo
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              Dates

                Created:
                Updated:
                Resolved: