Hi everyone! I've been trying to tweak my cyrus system to improve performance. I have a few programs (smtp-sink that came with postfix) that I use to test my server. I used smtp-sink to send 100 messages to a random set of 20 different accounts (2,000 messages total; average time to send is about 60 sec). That part works great, or well enough at least. :) It takes about 2 seconds to send 100. Not as fast as a lot of the other system specs I have seen out there, but I'm using mysql for virtual users and a ton of expensive filtering lookups in my mta, so it takes that long to shove them into the queue manager. Anyway, I've noticed that postfix can only deliver so many messages at a time to lmtp. I'm using lmtp as the delivery method, going over a local tcp/ip transport (I was using lmtp:unix files previously, no significant difference in performance between the two). After all of the mail is injected into the postfix queue, it takes about 30 seconds to deliver all 2,000 into the correct mailboxes. Really not that bad imho, but I'm wondering if it could be better. :) My goal is to get cyrus to keep up with postfix, if that's possible.
I've tried all sorts of things, mostly blind guesses though. I switched from lmtp:unix to straight lmtp tcp/ip, that didn't make a difference at all. I also disabled "duplicatesuppression" in imapd.conf at the expense of losing sieve (cringe), but that didn't make a significant difference either. It took about 40 seconds to deliver 2000 messages with duplicatesuppression enabled, about 8-10 seconds longer than when duplicatesuppression was disabled. Also, a postfix related control, I have lmtp_destination/recipient_concurrency_limit set to 300. I have expanded this as high as 1000 but with not impact, which leads me to believe there must be something I can do with cyrus to get it to accept more mail at one time. As a side note, when I run my programs, it brings my dual xeon 2.4ghz processors to 80% utilization (2 gigs of ram and raid 0). :D Not important to the problem I don't think, but there ya go anyway, just if you are curious. Any ideas? Let me know if I left something out. Cyrus IMAP4 v2.1.16 postfix 2.0.16 mysql 4.x (allows 1000 concurrent connections) Thanks!
