Hadoop Common
  1. Hadoop Common
  2. HADOOP-8770

NN should not RPC to self to find trash defaults (causes deadlock)

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Blocker Blocker
    • Resolution: Fixed
    • Affects Version/s: 2.0.2-alpha
    • Fix Version/s: 2.0.2-alpha
    • Component/s: trash
    • Labels:
      None
    • Hadoop Flags:
      Reviewed

      Description

      When transitioning a SBN to active, I ran into the following situation:

      • the TrashPolicy first gets loaded by an IPC Server Handler thread. The initialize function then tries to make an RPC to the same node to find out the defaults.
      • This is happening inside the NN write lock (since it's part of the active initialization). Hence, all of the other handler threads are already blocked waiting to get the NN lock.
      • Since no handler threads are free, the RPC blocks forever and the NN never enters active state.

      We need to have a general policy that the NN should never make RPCs to itself for any reason, due to potential for deadlocks like this.

      1. hdfs-3876.txt
        11 kB
        Eli Collins
      2. hdfs-3876.txt
        11 kB
        Eli Collins
      3. hdfs-3876.txt
        10 kB
        Eli Collins
      4. hdfs-3876.txt
        3 kB
        Eli Collins

        Issue Links

          Activity

          No work has yet been logged on this issue.

            People

            • Assignee:
              Eli Collins
              Reporter:
              Todd Lipcon
            • Votes:
              0 Vote for this issue
              Watchers:
              8 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved:

                Development