<div class="gmail_quote"><div class="gmail_quote"><div class="im">Hi Matthias, so just to re-iterate: we see this behavior only on one broker, other brokers with similar load don't exhibit the issue. We've never see that much i/o apart from when we hit the issues Matthew fixed for 2.4. Trying RabbitMQ 2.6 will take time as we have custom code and plugin we need to migrate. This issue only appears on production so there is no way for us to quickly try it.<div>
<br></div><div>Here is the CPU graph on the broker exhibiting the issue:</div></div><div><br><div>
<div><img src="cid:ii_133427722c75c7eb" alt="cpu_overview.png" title="cpu_overview.png"></div><div class="im"><div><br></div><div>And the load on a broker that does not:</div>
<div><br></div></div><div><img src="cid:ii_13342778042562ea" alt="cpu_overview2.png" title="cpu_overview2.png"><br></div><div class="im"><div><br></div><div>The spikes every minute is because we run rabbitmqctl list_queues every minute to monitor the queues. The spikes every 4 hours is due to a cleanup daemon that cleans up stale queues every 4 hours.</div>
<div> </div><div>--</div><div>Raphael.<div><div></div><div><br><br><div class="gmail_quote">On Wed, Oct 26, 2011 at 3:45 PM, Matthias Radestock <span dir="ltr"><<a href="mailto:matthias@rabbitmq.com" target="_blank">matthias@rabbitmq.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Raphael,<div><br>
<br>
On 25/10/11 17:23, Raphael Simon wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
All the messages are consumed pretty much immediately.<br>
</blockquote>
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That is irrelevant. Persistent messages sent to durable queues *always* get written to disk unless they can be sent to an auto-ack'ing consumer immediately.<br>
<br>
The next rabbit release contains an optimisation s.t. when messages get ack'ed before they have been written to disk then they won't be written to disk.<br>
<br>
The only thing slightly strange about what you have reported is the high write count. Any chance you could give RabbitMQ 2.6.1 a try?<br>
<br>
Regards,<br><font color="#888888">
<br>
Matthias.<br>
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