On Tue, Jan 02, 2007 at 11:23:10AM -0600, Steven F Siirila
wrote:> We are running Dovecot 1.0-rc15 on Solaris 10 and are starting to ramp up
> our user count and ran into a file descriptor limit:
>
> Jan 1 19:38:54 <hostname> dovecot: IMAP(username): Newly created
index file is corrupted: /home/username/.imap/foldername/dovecot.index.tmp
> Jan 1 19:38:54 <hostname> dovecot: IMAP(username): file
mail-index.c: line 1806 (mail_index_move_to_memory): assertion failed:
(index->fd == -1)
> Jan 1 19:38:54 <hostname> dovecot: pipe() failed: Too many open
files
> Jan 1 19:38:54 <hostname> dovecot: Temporary failure in creating
login processes, slowing down for now
>
> We got around this by calling "ulimit -n 512" and restarting
Dovecot.
We have since set this limit to "unlimited".
> This got us further (upwards of 300 concurrent users), but we are now
> running into what appears to be a full listen queue (connections are
> not rejected, but rather slow in being established).
This turned out to be a result of using the default value for
login_max_processes_count (128). We now have this set to 4096
in anticipation of our moving thousands more users to the server.
We've also bumped login_processes_count from 3 to 32.
> What I would like to know is if anyone else out there runs with large
numbers
> of concurrent IMAP sessions via Dovecot and has run into problems.
> If so, did you have to up your fd limit w/ulimit? Any other issues?
Is anyone else out there running with thousands of concurrent sessions?
On our older (existing) UW IMAP servers we have seen upwards of 3000
concurrent sessions.
--
Steven F. Siirila Office: Lind Hall, Room 130B
Internet Services E-mail: sfs at umn.edu
Office of Information Technology Voice: (612) 626-0244
University of Minnesota Fax: (612) 626-7593