I noticed from my experience that when you inject mail too fast on one qmail
instance, you can bring qmail to a seemingly halt, your concurrency can go
down from 200+ to just 5 or 6 after a few minuates, your mile may vary. I
suggest you to use multiple instances (N) and inject mail from 1 to N in
sequence. I found the result is incredible.
dp
-----Original Message-----
From: Ekker, Heinz [mailto:[EMAIL PROTECTED]]
Sent: Friday, December 10, 1999 7:55 AM
To: Qmail (E-Mail)
Subject: Performance?!
Hi!
When playing around with qmail I couldn't avoid noticing that I only reach a
poor performance. My tests run with some Perl-Scripts that send randomly
sized messages to random users via smtp. The message sizes average to ~100k.
When I first tested it, I used alias-expansion with the fastforward-package,
and to be honest, I was quite surprised to find that qmail could - on a
Pentium III 500 with 512 Megs RAM and a 19GB Level 1-RAID running RedHat,
2.2.13 with fd-patch - deliver only about 2 messages per second. The Queue
kept filling up, and half of the messages were not preprocessed. Only when I
let go of fastforward, I reached ~200 messages per minute and 17-18 MB of
throughput, which still seems very little. At least the preprocessing seemed
to work now. The CPU idles with 70, 80 %, there's plenty of RAM left. The
local concurrency never ever rises above 5.
I did my homework and dug through the archives of this mailing list, but the
only suggestions I found were (hopefully a joke) to take out the fsyncs
(which, BTW, didn't bring any increase) and people telling what good
performance they get with qmail(15, 20 messages per second? Still more? With
a lot less investment in hardware?).
Have you any suggestions for me on which type of hardware I should set up
qmail to reach similar results? We plan to move a medium site to qmail, and
I know there are severall still bigger ones running this mailserver.
Thanks in advance,
Heinz
