[rabbitmq-discuss] Resource alarms in 3.1 seems to block operations other than basic.publish

Mon May 13 19:04:53 BST 2013

On 13/05/13 18:53, Michael Klishin wrote:
> I don't set the watermark really low. Instead, I publish a lot of 2-16
> MB messages until the regular 40% watermark is hit
>
> The entire OS responsiveness is terrible.

Is the O/S paging perhaps? If this is your regular "desktop" machine, 
plus you are running rabbit and the clients on it, then I'd image by the 
time rabbit hits the regular 40% watermark the O/S may well have started 
paging quite heavily. And at that point *everything* gets a lot slower, 
and large processes, like rabbit at that time, will suffer particularly 
badly.

The 40% is a reasonable default for machines that don't run much besides 
rabbit and/or on which rabbit isn't put under heavy load. If those 
conditions aren't met then lowering the threshold is advisable.

Matthias.