Hi Gary,
Thanks for the explanation. The order is:
consumer retrieves message
connection is lost and consumer re-establishes connection to new
master broker
consumer acks the message retrieved from the former broker
consumer retrieves the same message it just ack'ed.
I guess the question is ... is there a way for the new broker on
failover to recognize the consumers that have retrieved message but not
ack'ed messages and behave exactly as if they were retrieved from itself
(not redispatch unless the connection to the consumer is lost)? I
suppose that would require some heuristics to determine how long to wait
before those original consumers reconnect.
Thanks
Josh
On 02/24/2010 04:16 PM, Gary Tully wrote:
On failover, redispatch of unacked messages will occur and this is
unordered. There is no guarantee that the same consumer will get the
same messages after failover of a connection.
On the java client there is a message audit that will suppress
duplicates that may occur, I think the same is true for the CPP
client, but this will not be true for STOMP clients.
What is odd is that you say that messages that have been acked are
replayed. This should only occur if the ack did not actually get to
the broker.
If previously acked messages are getting replayed there is something
wrong.
On 24 February 2010 19:02, Josh Carlson <jcarl...@e-dialog.com
<mailto:jcarl...@e-dialog.com>> wrote:
When using a shared file system master/server activemq
configuration and client acknoledgements we run into a problem when
our clients fail over to a new server. The problem is that the new
server does not appear to have any knowledge of pending
messages that the old server had dispatched to clients.
Consequently all of these pending messages get dispatched a second
time even though the clients had acknowledged them.
I've filed this as a bug here:
https://issues.apache.org/activemq/browse/AMQ-2627
which contains a reproducer using activemq-cpp. I'm posting here
in the hopes that someone can confirm that they believe this
something that is suppose to be supported and/or if anyone knows
of any possible work arounds.
Any advice is appreciated.
--
http://blog.garytully.com
Open Source Integration
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