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  1. ZooKeeper
  2. ZOOKEEPER-27

Unique DB identifiers for servers and clients

    Details

    • Type: New Feature
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 3.6.0
    • Component/s: c client, java client, server
    • Labels:
      None
    • Hadoop Flags:
      Incompatible change

      Description

      Moved from SourceForge to Apache.
      http://sourceforge.net/tracker/index.php?func=detail&aid=1937075&group_id=209147&atid=1008547

      here is the text from sourceforge:

      There should be a persistent unique identifier for an instance of ZooKeeper. Currently, if you bring a cluster down without stopping clients and reinitialize the servers, the servers will start logging client zxid errors because the clients have seen a later transaction than the server has. In reality the clients should detect that they are now talking to a new instance of the database and close the session.

      A similar problem occurs when a server fails in a cluster of three machines, and the other two machines are reinitialized and restarted. If the failed machine starts up again, there is a chance that the old machine may get elected leader (since it will have the highest zxid) and overwrite new data.

      A unique random id should probably get generated when a new cluster comes up. (It is easy to detect since the zxid will be zero.) Leader Election and the Leader should validate that the peers have the same database id. Clients should also validate that they are talking to servers with the same database id during a session.

        Issue Links

          Activity

          Hide
          phunt Patrick Hunt added a comment -

          Reassigning to Andew & Flavio.

          Andrew also mentioned that ZOOKEEPER-38 patch has support for reading/writing the dbid.

          Show
          phunt Patrick Hunt added a comment - Reassigning to Andew & Flavio. Andrew also mentioned that ZOOKEEPER-38 patch has support for reading/writing the dbid.
          Hide
          mahadev Mahadev konar added a comment -

          the dbids have been added to servers as a prt of ZOOKEEPER-38. Closing for now. When we need to have zookeeper client id's, we can open a new jira.

          Show
          mahadev Mahadev konar added a comment - the dbids have been added to servers as a prt of ZOOKEEPER-38 . Closing for now. When we need to have zookeeper client id's, we can open a new jira.
          Hide
          phunt Patrick Hunt added a comment -

          3.0.0 has been released, closing issues.

          Show
          phunt Patrick Hunt added a comment - 3.0.0 has been released, closing issues.
          Hide
          breed Benjamin Reed added a comment -

          had the joy of running into this problem today. this issue was prematurely closed.

          Show
          breed Benjamin Reed added a comment - had the joy of running into this problem today. this issue was prematurely closed.

            People

            • Assignee:
              Unassigned
              Reporter:
              phunt Patrick Hunt
            • Votes:
              0 Vote for this issue
              Watchers:
              4 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved:

                Development