[rabbitmq-discuss] Java client deadlock closing channel/connection

Thu Aug 23 12:54:08 BST 2012

Dharshan,

On 22/08/12 19:36, dharshanr wrote:
> My java client is hitting a deadlock closing a channel or a connection.
> I have also noticed that it hangs when deleting a queue as well. I have
> noticed this error when the server has a large number of connections.
> [...]
> Memory usage is 2.3GB where the high watermark is 1.5 GB.
> [...]
> Why is the memory usage above the watermark? From what I have read
> RabbitMQ moves the messages to disk and scales that way without using
> more memory.

Connections, channels and queues all take up memory. A single connection 
and channel with heartbeating takes up about 150kb. Idle & empty queues 
take up 10-20k each; 2-3 times that when active.

Furthermore, messages do always have an in-memory footprint of a couple 
hundred bytes even when paged to disk.

Regards,

Matthias.