I'm having a problem increasing the Postfix 2.5 smtpd process limit to 200. Here's what I have tried so far:
1)
/etc/postfix/main.cf:
default_process_limit = 200
2)
/etc/postfix/master.cf:
smtp inet n - - - 200 smtpd
3)
/etc/postfix/master.cf:
smtp inet n - - - - smtpd
-o default_process_limit=200
During heavy traffic or simulation (stress test), the number of smtpd processes reaches the default limit, whereupon the server stops accepting new connections:
$ ps -u postfix | wc -l
101
N.B. There are no other bottlenecks in this state (according to atop).
Error messages:
warning: process /usr/lib/postfix/smtpd pid 25834 exit status 1
warning: /usr/lib/postfix/smtpd: bad command startup -- throttling
setuid(105): Resource temporarily unavailable
/etc/security/limits.conf:
postfix soft nproc 200
postfix hard nproc 300
Could any of you give me a hint, please?
---------- Post updated 10-31-09 at 02:06 PM ---------- Previous update was 10-30-09 at 05:56 PM ----------
Well, evidently the directives in limits.conf are completely ignored in our distribution/setup.
As a temporary solution, I placed "ulimit -u 300" in the Postfix init script.
300 smtpd processes can now be spawned, even though the process limit in master is only 200 (!).