[rabbitmq-discuss] Exactly Once Delivery

[Matthew Sackman]

On Thu, Aug 05, 2010 at 10:28:17PM -0400, Mike Petrusis wrote:
> Can messages get duplicated while they are propagating in the broker?  If duplicates are produced in the broker they will have the same "republish count" and this method won't work.  

Well, a message that is sent to an exchange which then results in the
message going to several queues will obviously be duplicated. But
presumably in that case, your consumers consuming from the different
queues would be doing different tasks with the messages, hence the need
for the different queues in the first place.

That aside, no, within a queue, Rabbit does not arbitrarily duplicate
messages.

Matthew