Noel Jones wrote:
Mark Goodge wrote:
I'm hoping someone can help point me in the right direction for the
solution to this one. I'm in the process of adding a new server to an
existing mail cluster, but for some reason I'm getting really slow
throughput. The problem seems to be delays in the active queue -
here's a sample from qshape:
T 5 10 20 40 80 160 320 640 1280 1280+
TOTAL 253 0 0 0 0 252 1 0 0 0 0
example.com 18 0 0 0 0 18 0 0 0 0 0
example.net 16 0 0 0 0 16 0 0 0 0 0
I strongly suspect that your amavisd-new is the bottleneck.
Examine your logs and the output of the amavisd-nanny program.
Well, disabling the content filter does improve performance, but it
still isn't as good as it ought to be. So I still have a little bit of a
mystery.
Amavisd will log timing breakdowns at log_level 2 or higher; that can be
useful to see where it's spending its time. Slow DNS can cause
SpamAssassin to take longer than expected to process mail.
amavisd-nanny will show how many amavisd-new threads are available and
how many are being used - maybe you don't have enough configured or they
aren't all being used for some reason.
I believe there was a patch for qshape posted a while back that changes
it to show mail waiting for the content_filter, rather than the final
destination. Search the archives...
Ah, now that could be very useful. Thanks for the suggestion.
Or maybe just a boring old networking problem, such as a duplex mismatch
or flaky cable, that's dramatically slowing down transmission.
Trust me, we've already tried checking every possible bit of hardware in
the chain ;-)
Mark
--
http://mark.goodge.co.uk - my pointless blog
http://www.good-stuff.co.uk - my less pointless stuff
