On Wed, 21 Feb 2007, Chris Wakelin wrote:
Date: Wed, 21 Feb 2007 17:40:31 +0000 From: Chris Wakelin c.d.wakelin@reading.ac.uk To: Steven F Siirila sfs@tc.umn.edu Cc: dovecot@dovecot.org Subject: Re: [Dovecot] Solaris/SSLonly/Lots of Users
Steven F Siirila wrote:
Anyone running Dovecot on Solaris, requiring only SSL connections, and servicing thousands of simultaneous users? Our past attempts to do so have failed due to dovecot-auth using up all 256 of its file descriptors. I say 256 since we are limited to that by the 32-bit libraries. We are looking at either compiling Dovecot in 64-bit and letting dovecot-auth file descriptors accumulate (not ideal), or providing Timo with access to one of our test servers so he can debug the problem. However, I would like to hear of anyone in the same boat first. Thanks!
You don't need it to be 64-bit, just change the ulimit/plimit parameters on the processes (try "man plimit"). You can change the default by editing /etc/system
e.g.
set rlim_fd_cur=2048 set rlim_fd_max=2048
to set the limit to 2048. We run "plimit -n 4096" on the dovecot master process shortly after it starts and typically have 1200 or so concurrent IMAP processes. Also look at "login_process_per_connection = no" in the Dovecot configuration; this will mean the number of imap-login processes is much reduced at the loss of a bit of security.
In my case (Solaris 10), I have the following set in my /etc/system. This may be overkill/wrong:
- double file descriptor limits for dovecot set rlim_fd_cur = 65536 set rlim_fd_max = 131072
But things work.
Jeff Earickson Colby College