Zitat von Andre Nathan <andre@xxxxxxxxxxxxxxx>:
Hello
We have a cyrus server that runs under heavy load, and a few days ago it
started to show a behaviour where its lmtpd processes take a long time
to deliver messages sent from postfix. Below is an example of a postfix
log message. with the email address removed:
Feb 28 17:14:11 mta13 postfix/lmtp[9633]: 63CBA700071C:
to=<user=domain.com@xxxxxxxxxxxxxxxxxxxxx>,
relay=box2.prv.f3.k8.com.br[10.8.5.49]:2003, conn_use=6, delay=1718,
delays=0.15/1118/0/600, dsn=4.4.2, status=deferred (conversation with
box2.prv.f3.k8.com.br[10.8.5.49] timed out while sending end of data --
message may be sent more than once)
The last field in the "delays" field shows that the time out occurred
after 600s trying to send the message to cyrus. Even when a timeout does
not occur, the time for the message to be sent is around 100-300s.
We have some other more lightly loaded servers in which the data is sent
to lmtpd very quickly, and at any given moment there are only a few
lmtpd's running. On the heavily loaded servers, there are always a few
thousand lmtpd processes.
???
A few thousand lmtpd would be *way* too much because they all use the
same I/O bottleneck (if you don't have partitions on different I/O
paths). For a single I/O path i would recommend not more than some 10
.. 20 concurrent lmtpd with the exception if you are having complex
sieve rules which adds to latency.
Regards
Andreas
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