[rabbitmq-discuss] does rabbit eat memory?

[Matthew Sackman]

If messages are being delivered to a consumer and no_ack/auto_ack is
false, then responsibility for that message remains with the broker
until the consumer:
i) acks the message
ii) closes the channel or connection (either politely or by crashing)
iii) nacks or in some way explicitly requeues the message

In the case of (i), at that point the broker can forget about the
message. In the other cases, the broker reinjects the message to the
rear of the queue, thus making the message available for delivery to
others.

Matthew