Patrick Chemla:
> >> But the CPU of the box is idle more than 80%. It is clear that it is not a
> >> matter of CPU, nor memory, nor disk. Something in the number of
> >> processes/users/simultaneous tasks is blocking.
Indeed, the symptom of blocking is in the third field of
the Postfix "delays" logging.
The format of the "delays=a/b/c/d" logging is as follows:
o a = time from message arrival to last active queue entry
o b = time from last active queue entry to connection setup
o c = time in connection setup, including DNS, EHLO and TLS
o d = time in message transmission
In your case, it takes a minute or more to set up the connection
including DNS lookup and EHLO handshake. That is holding up your mail.
- Check if the qmail servers are responsive (telnet hostname 25).
- Check if your Postfix needs a /var/spool/postfix/etc/resolv.conf
file, and if that file is consistent with /etc/resolv.conf. If
Postfix needs /var/spool/postfix/etc/resolv.conf and the file
is missong or contains a bogus server that will add time to
your deliveries.
- If they aren't, increase the concurrency on the qmail side.
Wietse
