Uploaded image for project: 'Hadoop HDFS'
  1. Hadoop HDFS
  2. HDFS-1623 High Availability Framework for HDFS NN
  3. HDFS-2693

Synchronization issues around state transition

    XMLWordPrintableJSON

    Details

    • Type: Sub-task
    • Status: Resolved
    • Priority: Critical
    • Resolution: Fixed
    • Affects Version/s: HA branch (HDFS-1623)
    • Fix Version/s: HA branch (HDFS-1623)
    • Component/s: ha, namenode
    • Labels:
      None

      Description

      Currently when the NN changes state, it does so without synchronization. In particular, the state transition function does:
      (1) leave old state
      (2) change state variable
      (3) enter new state

      This means that the NN is marked as "active" before it has actually transitioned to active mode and opened its edit logs. This gives a window where write transactions can come in and the checkOperation allows them, but then they fail because the edit log is not yet opened.

        Attachments

        1. hdfs-2693.txt
          63 kB
          Todd Lipcon
        2. hdfs-2693.txt
          63 kB
          Todd Lipcon
        3. hdfs-2693.txt
          58 kB
          Todd Lipcon
        4. hdfs-2693.txt
          58 kB
          Todd Lipcon
        5. hdfs-2693.txt
          52 kB
          Todd Lipcon

          Issue Links

            Activity

              People

              • Assignee:
                tlipcon Todd Lipcon
                Reporter:
                tlipcon Todd Lipcon
              • Votes:
                0 Vote for this issue
                Watchers:
                6 Start watching this issue

                Dates

                • Created:
                  Updated:
                  Resolved: