ZooKeeper
  1. ZooKeeper
  2. ZOOKEEPER-335 zookeeper servers should commit the new leader txn to their logs.
  3. ZOOKEEPER-1082

modify leader election to correctly take into account current epoch

        Details

        • Type: Sub-task Sub-task
        • Status: Closed
        • Priority: Major Major
        • Resolution: Fixed
        • Affects Version/s: None
        • Fix Version/s: 3.4.0
        • Component/s: server
        • Labels:
          None
        • Release Note:
          Committed revision 1135382.

          Description

          when comparing zxids for leader election, the current epoch of the peer needs to be taken into account.

          1. Text File
            ZOOKEEPER-1082.patch
            20 kB
            Flavio Junqueira
          2. Text File
            ZOOKEEPER-1082.patch
            20 kB
            Flavio Junqueira

            Activity

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            Vishal Kher added a comment -

            Hi Ben,

            Can you please elaborate the situations where the epoch is not currectly accounted for?

            Thanks,
            -Vishal

            Show
            Vishal Kher added a comment - Hi Ben, Can you please elaborate the situations where the epoch is not currectly accounted for? Thanks, -Vishal
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            Flavio Junqueira added a comment -

            This is actually part of the changes that we are proposing to the Zab implementation, detailed in the wiki, and this particular sub-task is related to a change in leader election. The election needs to take into account not only the highest zxid, but also the epoch of the leader, which might not be the same as the epoch of the last zxid.

            Show
            Flavio Junqueira added a comment - This is actually part of the changes that we are proposing to the Zab implementation, detailed in the wiki, and this particular sub-task is related to a change in leader election. The election needs to take into account not only the highest zxid, but also the epoch of the leader, which might not be the same as the epoch of the last zxid.
            Hide
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            Flavio Junqueira added a comment -

            Preliminary patch. It is backward compatible, and tests pass for me. Also, FLELostMessageTest has notification messages hardcoded, which shows that it is backward compatible, but we probably want to implement a little more testing.

            Show
            Flavio Junqueira added a comment - Preliminary patch. It is backward compatible, and tests pass for me. Also, FLELostMessageTest has notification messages hardcoded, which shows that it is backward compatible, but we probably want to implement a little more testing.
            Hide
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            Flavio Junqueira added a comment -

            New version of the patch. I have cleaned up a bit and added an explicit FLEBackwardCompatibilityTest class. It is essentially a copy of FLELostMessageTest, but with a hardcoded messages that look like the current notifications in the trunk code.

            Also note that there are no modifications to LeaderElection, so LETest passing indicates that it is backward compatible with respect to that implementation of leader election.

            Show
            Flavio Junqueira added a comment - New version of the patch. I have cleaned up a bit and added an explicit FLEBackwardCompatibilityTest class. It is essentially a copy of FLELostMessageTest, but with a hardcoded messages that look like the current notifications in the trunk code. Also note that there are no modifications to LeaderElection, so LETest passing indicates that it is backward compatible with respect to that implementation of leader election.
            Hide
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            Hudson added a comment -

            Integrated in ZooKeeper-trunk #1215 (See https://builds.apache.org/job/ZooKeeper-trunk/1215/)

            Show
            Hudson added a comment - Integrated in ZooKeeper-trunk #1215 (See https://builds.apache.org/job/ZooKeeper-trunk/1215/ )

              People

              • Assignee:
                Flavio Junqueira
                Reporter:
                Benjamin Reed
              • Votes:
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                Watchers:
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                Dates

                • Created:
                  Updated:
                  Resolved:

                  Development