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<P CLASS="3339c1b0-7c42-495c-aca1-418120db7fdc"><div class=WordSection1><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I have a few questions – and I’d be very grateful if someone could point me in the right direction as to where to read more about the answers.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> 1)<span style='font-size:7.0pt'> </span>Headers exchanges <o:p></o:p></p><p style='margin-left:72.0pt'>a.<span style='font-size:7.0pt'> </span>I can see headers exchanges mentioned on <a href="http://www.rabbitmq.com/tutorials/amqp-concepts.html" target="_blank">http://www.rabbitmq.com/tutorials/amqp-concepts.html</a> but I can’t find any reference to it in the .NET client (for instance, it’s missing from the ExchangeType class) – even though the prototypes for ExchangeDeclare and QueueBind would seem to allow for a headers exchange to be handled. Is this just something that is ‘on the list’?<o:p></o:p></p><p style='margin-left:72.0pt'>b.<span style='font-size:7.0pt'> </span>I can’t find any documentation on exactly how header matching works. I can see it mentioned in section 3.1.3.4 of the AMQP 0.9.1 spec, but I can’t see any examples. For instance, if I wanted to match on messages where the ‘type’ header was ‘action’, the ‘sub-type’ header contained any value and the ‘source’ header was ‘distribution’ – would that be possible?<o:p></o:p></p><p>2)<span style='font-size:7.0pt'> </span>TxSelect, TxCommit and TxRollback<o:p></o:p></p><p style='margin-left:72.0pt'>a.<span style='font-size:7.0pt'> </span>I can’t really find any good examples of the usage or implications of transactions. My use case is that I want to receive a message, then generate 100 messages which either all get routed to their queue or not (basically an atomic publish) before acking the message that I receive. This is, in part, to allow for message durability to be handled in the broker (as per the ‘Not on message persistence’ that is about two-thirds of the way down <a href="http://www.rabbitmq.com/tutorials/tutorial-two-python.html" target="_blank">http://www.rabbitmq.com/tutorials/tutorial-two-python.html</a>). I wanted to know how TxCommit would react if the broker commit failed, and for this I had to re-compile the source because the documentation doesn’t say anything about it. As far as I can see a failed commit throws an UnexpectedMessageException. Is that right?<o:p></o:p></p><p style='margin-left:72.0pt'>b.<span style='font-size:7.0pt'> </span>While researching this, I found a recent commit which has the comment ‘<span style='color:black'>don't use tx in examples. The less it's mentioned the better.’. Why is that?</span><o:p></o:p></p><p style='margin-left:72.0pt'>c.<span style='font-size:7.0pt'> </span><span style='color:black'>In that commit, a message was changed to mention BasicQos instead of TxCommit – is that really the intention? Is there anywhere I can read more about that as the API documentation doesn’t give much away…</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Thanks very much!<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Matt<o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p></div></P>
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