[Dovecot] slow dict lookups?

[Anand Kumria]

Hi,

I am beginning to see many entries like:

Sep 10 21:32:06 mail1 dovecot: imap(user1 at example1.com): Warning:
read(/var/run/dovecot/dict): dict lookup took 20 seconds
Sep 10 21:32:11 mail1 dovecot: imap(user2 at example2.com): Warning:
read(/var/run/dovecot/dict): dict lookup took 25 seconds
Sep 10 21:32:16 mail1 dovecot: imap(user3 at example3.com): Warning:
read(/var/run/dovecot/dict): dict lookup took 30 seconds
Sep 10 21:32:21 mail1 dovecot: imap(user3 at example3.com): Error:
read(/var/run/dovecot/dict) failed: Timeout after 30 seconds
Sep 10 21:32:21 mail1 dovecot: imap(user1 at example1.com): Warning:
read(/var/run/dovecot/dict): dict lookup took 25 seconds
Sep 10 21:32:21 mail1 dovecot: imap(user4 at example2.com): Warning:
read(/var/run/dovecot/dict): dict lookup took 24 seconds
Sep 10 21:32:26 mail1 dovecot: imap(user5 at example2.com): Warning:
read(/var/run/dovecot/dict): dict lookup took 29 seconds

What is the best way to look into making dict lookups faster?

In my case the dict is use for user / domain quotas and is looked up via
Postgres (on another host). Is there further logging I can enable to see
where the problem is?

Thanks,
Anand