On Mon, Dec 17, 2001 at 05:22:37PM -0800, Bill Moseley wrote: > At 04:26 PM 12/17/01 -0800, J C Lawrence wrote: > >On Mon, 17 Dec 2001 15:32:39 -0800 > >Bill Moseley <[EMAIL PROTECTED]> wrote: > > > >> Someone posted a few days or so ago asking about list sizes. Was > >> there any response to that query? > > > >Yup, and its already in the FAQ. > > http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq01.015.htp > > Now, anyone available to fill in the blanks for qmail or Postfix tuning?
I'll try to start that ball rolling. As lists get larger, Postfix delivery with out-of-the box configuration really slows down. The bottlenecks I've found are queue length and number of SMTP processes, both of which default to values too small for large lists. I began noticing pretty severe rate limiting at about 10,000 deliveries on a list. To get the number of SMTP processes up, change "default_process_limit" in main.cf. default_process_limit = 150 gave results I could live with. There's an active message queue which also became a sticky wicket for us. Two limits which affect this, and the values I arrived at by experiment are: qmgr_message_active_limit = 40000 qmgr_message_recipient_limit = 40000 Default on both of these is 1000, as of the Postfix version I initially installed. The comments in the config file say: # The qmgr_message_active_limit parameter limits the number of # messages in the active queue. # The qmgr_message_recipient_limit parameter limits the number of # in-memory recipients. This parameter also limits the size of the # short-term, in-memory destination status cache. With these changes in place, a K6-350 with 128M RAM delivers messages averaging perhaps 3K over a medium-speed DSL, without entirely saturating the DSL, at load average below 2.0, without impinging on swap. It'll reach 20,000 recipients in a couple of hours. Another common recommendation with Postfix is to set disable_dns_lookups = yes a measure others have reported favorably on, but which I have not yet tried. After changing parameters in main.cf, run "postfix reload" then look at the process table to see if the postfix processes are running, and how many smtp processes are working at it. mailq gives a report of what's in process and is a great help in tuning. A crude index of what's out there is mailq | grep '^[A-Z0-9]' | wc -l and variations. -- ----------------------------------------------------------------- Dan Wilder <[EMAIL PROTECTED]> Technical Manager & Editor SSC, Inc. P.O. Box 55549 Phone: 206-782-8808 Seattle, WA 98155-0549 URL http://embedded.linuxjournal.com/ ----------------------------------------------------------------- ------------------------------------------------------ Mailman-Users maillist - [EMAIL PROTECTED] http://mail.python.org/mailman/listinfo/mailman-users