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  1. JGroups
  2. JGRP-1481

SEQUENCER can try forwarding to null coordinator

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    Details

    • Type: Bug
    • Status: Resolved (View Workflow)
    • Priority: Major
    • Resolution: Done
    • Affects Version/s: 3.0.10
    • Fix Version/s: 3.1
    • Labels:
      None

      Description

      I've just seen a group go wrong and I think that the first sign of trouble was this line of trace:

      2012-06-15 08:55:54.690 [ForkJoinPool-1-worker-0] TRACE org.jgroups.protocols.SEQUENCER - [CFS-A-four]: forwarding CFS-A-four::1 to coord null
      

      ... showing a member trying to forward to a null coordinator.

      This comes shortly after a new view was installed so SEQUENCER should have seen the VIEW_CHANGE. I think that the suspect code is in handleViewChange()

              if(!coord_changed) {
                  setCoord(new_coord);
                  return;
              }
      

      Surely the intention isn't to call setCoord only if the coodinator hasn't changed?

      I see that setCoord will get called in due course by the flusher. But perhaps it would be safer to do something like:

              if(!coord_changed) {
                  return;
              }
      
              stopFlusher();
              setCoord(new_coord);
              startFlusher(new_coord); // needs to be done in the background, to prevent blocking if down() would block
      

      ... and possibly the call to setCoord in flush() can then be removed?

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            Assignee:
            belaban Bela Ban
            Reporter:
            dimbleby David Hotham (Inactive)
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              Created:
              Updated:
              Resolved: