[Dovecot] Problem with process_limit

[Jack Bates]

On 10/1/2012 4:15 AM, FABIO FERRARI wrote:
> Hello,
>
> i have a problem with the process_limit configuration.
>
> Occasionally, it happens that the dovecot.log shows this line:
> master: Warning: service(imap): process_limit reached, client connections
> are being dropped
>
> So I checked, the process number, with the command:
> ps auxwww | grep imap | grep -v login | wc -l
> and it shows 1024.
>
> Then, i edited the file /etc/dovecot/conf.d/10-master.conf and set the line
> process_limit = 1500
>
> I checked if the dovecot had accepted the change with the command
> doveconf -n | grep process_limit
> and it shows
> process_limit = 1500
>
> But it is dropping the connections when they reach 1024 anyway, the
> configuration parameter is totally ignored.
>
> Can anyone help? Am I editing the right parameter?
>
> thanks in advance
>
> Fabio Ferrari
>
> P.S. The version of the dovecot is dovecot-2.0.1-1_118.el5 on Red Hat
> Enterprise Linux Server release 5.8 (Tikanga).

Don't forget to change the operating system limit as well. I added these 
lines to my /etc/sysconfig/dovecot on rhel6. I compiled dovecot myself, 
but I package similar to the system version.

ulimit -n 4096
ulimit -u 5120

This increases the filehandles allowed by dovecot to 4096 and increases 
the number of processes per user to 5120. This is a proxy server, so I 
needed to support much larger numbers. than a silly 1024.

Jack