It is possible that 4 made it on the "extra" message in a buffer, but your client did not yet see it. If you have CLIENT_ACKNOWLEDGE you will then ack all messages on the session, to truly force ack of everything you can use AMQ's INDIVIDUAL_ACKNOWLEDGEMENT
> But I'll ask it anyway... > > Client(s) receiving from a topic messages 1, 2, 3 and 4. prefetch is set to > 1, client to ACK. Msgs 1,2 come in and are ACK'd. Msg 3 comes in but is not > ACK'd. Does msg 4 make it through or must 3 be either ACK'd or expired > first? > > I am expecting that the queue comes to a halt unless msg 3 is "dealt > with"... Something's just been noticed which causes me to ask to confirm > this... :-) > > James
