[rabbitmq-discuss] Queue has inaccessible messages?

[David King]

I have a moderate-traffic queue on rabbit 1.8.1 that for some reason doesn't ever get smaller than 1.3k (as reported by rabbitmqctl list_queues).  http://i.imgur.com/m6Zva.png

> ri at queue01:~$ rabbitmqctl list_queues name messages_ready messages_unacknowledged messages memory | grep indextank_changes
> indextank_changes       10      1342    1352    91015008

The queue has two consumers that have been killed/restarted (several times), so it's not a matter of them being stuck in a consumer. It's not an issue of not being able to process them fast enough, because if I shut off the consumers to let the queue grow a bit then turn them back on, messages are processed down to that point near-instantly (that's the giant spike in the aforelinked graph).

Any idea why these messages can't be retrieved?