[Dovecot] too many open files and v1.2

[Michael Moritz]

Hi Timo

thanks for your reply. I understand you're basically saying "upgrade to v2" but maybe this could be of interest for you. After we lowered the  login_max_processes_count again the problem reappeared so I'm not sure whether that doesn't indicate a different problem.

Regards,

Michael

On Tuesday 18 October 2011 15:57:23 Timo Sirainen wrote:
> On Thu, 2011-10-06 at 12:42 +0100, Michael Moritz wrote:
> > Hi
> > 
> > I've found an older thread http://www.dovecot.org/list/dovecot/2010-March/047886.html which mentions that this is a bug in version 1. I'm on Debian squeeze (1:1.2.15-7) and got errors like these recently
> > 
> > Oct  5 11:29:29 mail dovecot: dovecot: pipe() failed: Too many open files
> > Oct  5 11:29:32 mail dovecot: dovecot: pipe() failed: Too many open files
> > Oct  5 11:29:32 mail dovecot: dovecot: Temporary failure in creating login processes, slowing down for now
> 
> These errors come from the dovecot master process. Each child process
> uses up a few fds for pipes.
> 
> > As a work around I've increased login_max_processes_count from 256 to 512 and it seems to have helped (as I suspected stale opened files).
> 
> That only makes it easier to reach, since now there can be more child
> processes eating up more fds.
> 
> > My colleague thinks it's hitting the kernel open file limit ulimit -n (currently at 1024) but I don't see how that could happen if the number of process is nowhere near that.
> 
> I don't remember how many fds each process takes in v1.x, probably
> between 1 and 3. So if you for a while had hundreds of imap or pop3
> processes, you could run into that limit.
> 
> v2.x doesn't use as many fds.
> 
>