On 1/29/2010 1:37 AM, Stan Hoeppner wrote:
Stan Hoeppner put forth on 1/29/2010 12:27 AM:
Based on purely visual non-scientific observation (top), it seems my smtpd
processes on my MX hang around much longer in (Debian) 2.5.5 than they did in
(Debian) 2.3.8. In 2.3.8 Master seemed to build them and tear them down very
quickly after the transaction was complete. An smtpd process' lifespan was
usually 10 seconds or less on my 2.3.8. In 2.5.5 smtpd's seem to hang around
for up to 30 secs to a minute.
Local shows very speedy delivery. Is this "long" smtpd process lifespan normal
for 2.5.5 or did I do something screwy/wrong in my config?
relay=local, delay=2.2, delays=2.2/0/0/0.01, dsn=2.0.0, status=sent
relay=local, delay=0.32, delays=0.29/0.02/0/0, dsn=2.0.0, status=sent
relay=local, delay=0.77, delays=0.75/0.03/0/0, dsn=2.0.0, status=sent
relay=local, delay=0.26, delays=0.25/0/0/0.01, dsn=2.0.0, status=sent
relay=local, delay=0.64, delays=0.62/0.03/0/0, dsn=2.0.0, status=sent
relay=local, delay=0.26, delays=0.25/0/0/0, dsn=2.0.0, status=sent
I think I found it:
max_idle = x
The default is 100 on my system. I changed it to 10 and that seems to have had
an effect.
Did this setting exist in 2.3.8? I didn't see a version note next to max_idle
in my 2.5.5 man smtpd. If so, was the default something insanely low like 1, or
0? Like I said, smtpd's seemed to come and go in a hurry on 2.3.8.
Nitpick: you talk about smtpd, then show log snips from smtp.
But no matter, they both honor max_idle and will behave in a
similar manner.
The max_idle default has been 100s pretty much forever. The
idea is that an idle postfix process will be reused to do more
work rather than starting a new process every time. This
makes postfix *far* more efficient than one process per job.
Although the 100s default is somewhat arbitrary, I have
trouble imagining a situation where a shorter max_idle makes
sense. On a very lightly loaded system where processes are
seldom reused, a shorter max_idle might not hurt anything, but
it won't help anything either.
-- Noel Jones
