[rabbitmq-discuss] number of Erlang processes being used?

[Matthew Sackman]

On Fri, Sep 24, 2010 at 12:07:13PM +0100, Mario Menti wrote:
> Is there a way to see the number of lightweight Erlang processes
> currently in use by rabbitmq? We regularly run out of them, even
> with a higher-than-default number being specified (65535), and while
> I realise that there may be an underlying issue, it would still be
> very useful to monitor the usage.

No - there's no way of figuring this out other than the total number of
processes being used in the erlang VM. Thus if you're using other
applications within the same VM, you won't be able to separate them out.

length(erlang:processes()).
 will tell you the total number of processes running in the VM.

Btw, you're not helping yourselves by running such an old version - we
pushed the default limit up to 1e6 around 1.8. You shouldn't have many
concerns with raising your limit substantially further (though it will
mean the VM will take up a bit more memory which might be relevant if
you're running in an embedded environment). The absolute maximum is 16bn
but if you use that I think I found the base VM on its own takes up some
400MB after booting (just due to the various arrays and bookkeeping
needed for every process). Given your 24GB of RAM, I would think that
you're not in an embedded enviroment and such paltry amounts of memory
are not a concern!

Matthew