[rabbitmq-discuss] File Description Exhaustion with Transient Messages

Fri Mar 14 18:28:00 GMT 2014

On 14/03/14 18:01, Chris Larsen wrote:
> We had a 3.1.5 node exhaust the 65K FDs allocated to MQ

Did rabbit actually run out of file descriptors, i.e. did you see any 
corresponding errors in the logs or were unable to establish new 
connections?

> Lsof shows that there are of 50K handles consumed with references to the
> transient message store, e.g. “msg_store_transient/352.rdq”.

Do you have 50k .rdq files? If so then that 50k handle figure is plausible.

Rabbit will use as many file descriptors a it deems useful for best 
performance. But most of these are "soft" file handles; when more file 
descriptors are needed for, say, accepting connections, then rabbit will 
close some of these soft handles in order to free up handles.

So high file descriptor counts are nothing to worry about, but if you 
see rabbit actually running out of descriptors (as per my first question 
above) then that would indicate a bug somewhere.

Matthias.