[rabbitmq-discuss] RabbitMQ QUEUE MESSAGES

Wed Jul 24 11:36:02 BST 2013

On 24/07/13 11:01, rabbit15 wrote:
> The number of current published messages is from last 5 seconds and the
> graph was taken from last hour, so there is approximately value on the
> graph. The value of publishing was from 0 to 50k (as you have seen) in the
> second part.

Are you saying the publishing rate fluctuates between 0 and 50kHz? Any 
idea why that is?

> I have also the question about:
> "The complexity of delivering messages to
> consumers and of processing an acknowledgement is
> O(log(number_of_unacknowledged_messages))."
>
> In my system there is a lot of free memory so why it slows down ?

The above has nothing to do with memory but the computational complexity 
of working with the data structures involved. i.e. pending acks are 
recorded in a gb-tree, which has O(log(N)) insert/removal complexity.

> <http://rabbitmq.1065348.n5.nabble.com/file/n28335/Nabble2.png>

That graph is somewhat less conclusive than the previous one; it shows 
fluctuation rather than a sudden drop.

Can you

(a) reduce your tests to the minimum setup that reproduces the issue? 
You seem to have a lot of connections, channels and queues that don't do 
very much; I suspect it's safe to remove those. And...

(b) post the code & instructions for us to reproduce the problem?

Regards,

Matthias.