<div dir="ltr">Why don't you just subscribe to that queue with basic.consume, acks on, and a prefetch of 1<div><br></div><div>When you get a message, reject it and cancel your consumer (if your logic calls for it). </div>
<div><br></div><div>The message will be at the front of the queue.</div><div><br></div><div>Then spawn your 'consumer process'. The message (and any others) will be there waiting.</div><div><br></div><div>I use python pika async to do this sort of thing. Event driven, no polling.</div>
<div><br></div><div>If speed is important, use the tornado adapter; if you are feeling lucky, use the libev adapter (full disclosure: I wrote it)</div><div><br></div><div>-ml</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">
On Mon, Sep 9, 2013 at 7:20 PM, vitaly <span dir="ltr"><<a href="mailto:vitaly.krugl.numenta@gmail.com" target="_blank">vitaly.krugl.numenta@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><span style="border-spacing:0px;border-collapse:separate;font-size:medium;font-family:Calibri"><span style="font-family:Calibri,sans-serif;font-size:14px"><div>I need to be able to spawn a consumer process for a queue when that queue becomes non-empty. The trigger needs to happen in an event-driven way, without polling, and without removing any messages from that queue. Is this possible with AMQP/RabbitMQ and how? I am coding in Python.</div>
<div><br></div><div>Thank you,</div><div>Vitaly</div></span></span></div><br>_______________________________________________<br>
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