<div dir="ltr">Hi, we were hoping to get some pointers in looking into this problem. We're running rabbitmq 2.7.1-1 in a xen VM on debian 6 squeeze.<div><br></div><div>We generally process about 20 messages/sec, with occasional transient spikes to 500.</div>
<div><br></div><div>We recently added a new queue and saw the disk utilization jump to 60-80% and the iowait to 40-60%. Read sectors/sec is around 0, and write sectors/sec is about 1k, which is unchanged from before adding this new queue.</div>
<div><br></div><div>The input and output on this new queue is only 1-10 per second. The messages in it are only 60-70 bytes. We currently have a backlog of about 100,000 messages in the queue, we maxed out at 250,000.</div>
<div><br></div><div>The individual consumers of this new queue don't fetch that many messages--the work they're associated with takes 1-30 seconds to perform. We're using STOMP as a message transport.<br></div>
<div><br></div><div>The problem is that every consumer we add to the queue seems to increase disk activity by about 10%, and by the time we have 8 consumers, the rabbitmq server is overloaded enough that other queues start falling behind in their deliveries. <br>
</div><div><br></div><div style>If we shut off all the consumers on the new queue, disk activity immediately falls to easily sustainable levels (near zero iowait).</div><div style><br></div><div style>Is there anything we can look at to get further information on the problem? Any pointers you have would be helpful. Thanks!<br>
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