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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">(this message is intended as a reply to <a href="https://groups.google.com/forum/#!searchin/rabbitmq-discuss/publisher$20ack$20order/rabbitmq-discuss/0O8Dick9xGA/7mGy8ebV1gUJ">
https://groups.google.com/forum/#!searchin/rabbitmq-discuss/publisher$20ack$20order/rabbitmq-discuss/0O8Dick9xGA/7mGy8ebV1gUJ</a> )<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Assuming that a few messages succeed in order, I sometimes see the ACKs like this (RabbitMQ 3.1.1):<o:p></o:p></p>
<p class="MsoNormal">ACK(5, true)<o:p></o:p></p>
<p class="MsoNormal">ACK(1, false) -- surely sent first by the broker, but lagged a bit longer on the wire<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">No problem here, I can handle that, though message 1 appears to be ACKed twice, and documentation says "After a channel is put into confirm mode, all subsequently published messages will be confirmed or nack'd once." which should probably
read as "at least once".<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Now the problem, which I haven't observed as it should be extremely rare but which still is possible:<o:p></o:p></p>
<p class="MsoNormal">ACK (5, true)<o:p></o:p></p>
<p class="MsoNormal">NACK (1, false) -- sent first by broker but received last.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Since the client may have already acted upon the ACK, there's a problem here. Or did I miss something?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Regards,<o:p></o:p></p>
<p class="MsoNormal">Tobias<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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