[Dovecot] process_min_avail being ignored?

[Douglas Mortensen]

Today I found out we are having users w/ problems because:

Mar  3 09:57:33 jlgray dovecot: master: Warning: service(imap-login): process_limit reached, client connections are being dropped
Mar  3 09:58:42 jlgray dovecot: master: Warning: service(imap-login): process_limit reached, client connections are being dropped
Mar  3 10:02:51 jlgray dovecot: master: Warning: service(imap-login): process_limit reached, client connections are being dropped
Mar  3 10:04:29 jlgray dovecot: master: Warning: service(imap-login): process_limit reached, client connections are being dropped
Mar  3 10:05:41 jlgray dovecot: master: Warning: service(imap-login): process_limit reached, client connections are being dropped
Mar  3 10:06:58 jlgray dovecot: master: Warning: service(imap-login): process_limit reached, client connections are being dropped

So, based on the dovecot2 wiki, it would seem that the solution is to follow the recommendations at http://wiki2.dovecot.org/LoginProcess, and use them as a guide for our situation.

I have done so. But unless I misunderstand their purpose, I don't think they're working. Maybe I don't have them in the correct place?? I am expecting the imap-login process count to immediately jump up to 200 (based on my config below). But instead, they just slowly gradually increase. But even an hour after changing the config & restarting dovecot, I only have 78 login processes.

dovecot -n output is:

# 2.0.9: /usr/local/etc/dovecot/dovecot.conf
# OS: Linux 2.6.32-5-amd64 x86_64 Debian 6.0
auth_debug = yes
auth_mechanisms = plain login
disable_plaintext_auth = no
log_timestamp = "%Y-%m-%d %H:%M:%S "
mail_debug = yes
mail_location = maildir:~/
mail_privileged_group = mail
passdb {
  driver = pam
}
protocols = imap pop3
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
  user = root
}
ssl_cert = </etc/ssl/certs/jlgray.com.cer
ssl_key = </etc/ssl/private/jlgray.com.key
userdb {
  driver = passwd
}


This configuration was updated from a dovecot 1.x config, by following the instructions at: http://wiki2.dovecot.org/Upgrading/2.0
Namely: doveconf -n -c dovecot-1.conf > dovecot-2.conf
Then we renamed dovecot-2.conf to dovecot.conf

I'm pretty sure there were no problems with that part.

We are running dovecot 2.0.9 compiled from source.

OS is 64-bit Debian Squeeze (6.0), as shown by  'cat /proc/version':
Linux version 2.6.32-5-amd64 (Debian 2.6.32-30) (ben at decadent.org.uk) (gcc version 4.3.5 (Debian 4.3.5-4) ) #1 SMP Wed Jan 12 03:40:32 UTC 2011

I really appreciate anyone helping me figure out why

Thanks,
-
Doug Mortensen
Network Consultant
Impala Networks Inc
CCNA, MCSA, Security+, A+
Linux+, Network+, Server+
.
www.impalanetworks.com
P: (505) 327-7300
F: (505) 327-7545