[rabbitmq-discuss] abnormally large memory use in "binaries"

Tue Oct 22 17:27:29 BST 2013

On 22 Oct 2013, at 20:20, Brian Hammond <brianin3d at yahoo.com> wrote:

> My understanding of pre-fetch was the consumer asks for that number of messages and then has to send an acknowledge before more messages are sent to it. If we have memory issues when there are almost no messages then our pre-fetch values seems an unlikely cause.

This is correct but note that basic.qos is set for a channel, not a consumer.

> If we set prefetch really low, I could see us having a lot of messages in the queue. Setting it high or unlimited should actually be better for the server.

RabbitMQ does not remove messages until they are acknowledged. Not using manual acknowledgements
may ease the pressure on the server, of course, if it's an option for your system.

MK