[Dovecot] [sfs: dovecot-auth file descriptor usage]

[Steven F Siirila]

I am re-posting this message from last Friday, as I have seen no replies.
It is critical that we address this problem, since until then we cannot
put more than a few hundred users on our server.

If Dovecot-auth TRULY needs to keep open a file descriptor for every single
login session, we will have to start looking at alternatives.

In short: Help!

----- Forwarded message from Steven F Siirila <sfs> -----

Date: Fri, 5 Jan 2007 13:55:38 -0600
From: Steven F Siirila <sfs>
To: dovecot at dovecot.org
Subject: dovecot-auth file descriptor usage
User-Agent: Mutt/1.4.2.1i

In dovecot-auth (rc15) we experienced problems when the file descriptors
reached 256 (due to a Solaris fdopen() call described previously).
The issue was that there was one file descriptor being used for every
imap-login and pop3-login process (in our environment of SSL-only that
means one for every active IMAP and POP connection).

Mods were made (and appear in rc16) to close out the descriptor in question
after using it during authentication (as I understand it).  However, I am
still seeing plenty of file descriptors left open in rc16 (one per session).
For example, on a Solaris 9 server with 9 IMAP connections open here is
an lsof excerpt of dovecot-auth:

dovecot-a 26071 root    7u  unix       105,136     0t79     3190 /devices/pseudo/tl at 0:ticots->/var/opt/dovecot/run/dovecot/login/default (0x3000d084250)
dovecot-a 26071 root    8u  unix       105,140     0t80     3190 /devices/pseudo/tl at 0:ticots->/var/opt/dovecot/run/dovecot/login/default (0x3c9c4227b68)
dovecot-a 26071 root    9u  unix       105,149     0t79     3190 /devices/pseudo/tl at 0:ticots->/var/opt/dovecot/run/dovecot/login/default (0x3cbaa7680b8)
dovecot-a 26071 root   10u  unix       105,266     0t79     3190 /devices/pseudo/tl at 0:ticots->/var/opt/dovecot/run/dovecot/login/default (0x3cbaa765d48)
dovecot-a 26071 root   11u  unix       105,160     0t79     3190 /devices/pseudo/tl at 0:ticots->/var/opt/dovecot/run/dovecot/login/default (0x3cbaa7667e0)
dovecot-a 26071 root   12u  unix       105,255     0t79     3190 /devices/pseudo/tl at 0:ticots->/var/opt/dovecot/run/dovecot/login/default (0x3cbaa769288)
dovecot-a 26071 root   13r  DOOR         265,0      0t0       50 /var/run (swap) (door to nscd[7752])
dovecot-a 26071 root   14u  unix       105,258     0t79     3190 /devices/pseudo/tl at 0:ticots->/var/opt/dovecot/run/dovecot/login/default (0x30002dc4008)
dovecot-a 26071 root   15u  unix       105,282     0t80     3190 /devices/pseudo/tl at 0:ticots->/var/opt/dovecot/run/dovecot/login/default (0x30003185738)
dovecot-a 26071 root   16u  unix       105,141     0t80     3190 /devices/pseudo/tl at 0:ticots->/var/opt/dovecot/run/dovecot/login/default (0x30003185ac8)

With the modification made, shouldn't these no longer accumulate?

-- 

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

----- End forwarded message -----

-- 

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