[jboss-jira] [JBoss JIRA] (JGRP-1481) SEQUENCER can try forwarding to null coordinator
[
https://issues.jboss.org/browse/JGRP-1481?page=com.atlassian.jira.plugin....
]
Bela Ban commented on JGRP-1481:
--------------------------------
OK, I agree on the first part: setCoord() should not be called when coord_changed is
false. This was done because originally setCoord() also set the 'view' field, but
since this is not the case anymore, I removed setCoord().
I don't think that setting the coordinator *before* flush() will work: in flush(), we
wait until all in-flight sending threads have completed and only *then* set coord, or else
existing threads might forward their messages to the new coordinator *before* the old
messages have been sent. This would be incorrect.
BTW: what did you mean when you said "a group go wrong" ?
I committed my changes, please take a look.
SEQUENCER can try forwarding to null coordinator
------------------------------------------------
Key: JGRP-1481
URL: https://issues.jboss.org/browse/JGRP-1481
Project: JGroups
Issue Type: Bug
Affects Versions: 3.0.10
Reporter: David Hotham
Assignee: Bela Ban
Fix For: 3.1
I've just seen a group go wrong and I think that the first sign of trouble was this
line of trace:
{noformat}
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
{noformat}
... 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()
{noformat}
if(!coord_changed) {
setCoord(new_coord);
return;
}
{noformat}
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:
{noformat}
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
{noformat}
... and possibly the call to setCoord in flush() can then be removed?
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.jboss.org/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira