Re: Postfix/Maildrop and too many connections issues

On Tuesday 21 June 2005 12:00 pm, Sven Willenberger wrote:
> We have a system set up whereby postfix and maildrop gather user
> info from a pg database (7.4.2 on FreeBSD 5.2.1) to do local mail
> acceptance and delivery. I have configured max connections at 512
> but I find that this is not enough and I get "connection limit
> exceeded for non-superusers" errors. I see upon ps ax that there
> are hundreds of idle connections (state I).

I have a vague recollection from the Postfix list that under some
circumstances Postfix does not explicitly close the connection to PG
so the back-end may stick around till the tcp connection times out.

In addition to ps, try "select * from pg_stat_activity()" and look at
connections via netstat (check from both ends) to hunt for clues.

I know that using old hardware and limiting Postfix to 200 connections
I've handled a constant rate of over 9 deliveries/second. Is your
mailserver load such that the need for 500+ simultaneous connections
passes the "sniff test"?

Cheers,
Steve