[rabbitmq-discuss] Ready, Unacked and Total messages of Queues

[Michael Klishin]

On 16 April 2014 at 07:41:47, Juno Chan (juno at algorithmictradinggroup.com) wrote:
> > In addition, when I set the prefetch count to 1, there should 
> be only 1 message delivered to the queue, why in my testing code, 
> there are still unack message#>1 ?

prefetch works per channel. If you use multiple channels or connections,
there can (and will) be multiple messages unacknowledged at a time.

> if the prefetch count is 1, unack message should always be in (0,1), 
> and ready message #will be increasing. will the increasing of 
> ready message count harming the performance on publisher (i.e. 
> cannot publish anything, or causing publishing application/machine 
> got stuck)? Though ready message # theoretically does not harm 
> rabbitMQ if not much diskI/O

This question was largely answered earlier. If a memory or available disk space
alarm is triggered, publishing connections will be blocked:

http://rabbitmq.com/memory.html
-- 
MK 

Software Engineer, Pivotal/RabbitMQ