[Mailman-Users] Big Lists

Dan Wilder dan at ssc.com
Tue Dec 18 05:33:23 CET 2001

On Mon, Dec 17, 2001 at 06:39:54PM -0800, J C Lawrence wrote:
> On Mon, 17 Dec 2001 18:01:56 -0800 
> Dan Wilder <dan at ssc.com> wrote:
> > 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.
> Without those changes in place (more exctly, using the Debian/Linux
> defaults) a Dual PII-333 on the end of a Tier 2 T3 has regularly
> sustained just under 1,400 deliveries (to target MX) per minute for
> me.  While I've not maintained that level for more than single digit
> minutes (not enough traffic) that sums to 80K messages per hour.
> I've been happy enough with those numbers for the box in question
> that I haven't looked further.

I began to see signs of thrashing some place between a couple
of thousand recipients, and 10,000.  There was what appeared to
be a phase transition of sorts, above which waits began to
predominate and I believe delivery rate may have even gone

I'm not getting anything like 1400 deliveries/minute (I don't
think).  I'll try measuring delivery rate during this week's 
large announce-lists posting, then next week set disable_dns_lookups
and see what change there may be. 

The DSL does get to be pretty much of a nuisance to run vi on
over an ssh connection, when the list mail is going out.

The local copy of BIND is something I'd neglected to mention.
We use split DNS, with internal copies of BIND claiming to
be definitive for our domain, forwarding queries with respect
to other domains outside.  The mailing list server does
auxilliary duty as second internal MX server, so there's a
copy of BIND running on it, as well as Postfix/Mailman.
It looks to itself first for all name resolution.

> And no, it doesn't even begin to saturate available b/w.
> > disable_dns_lookups = yes
> I do have this set.  I also have a local copy of BIND 9 listening on
> localhost only.
> > mailq
> FWVLIW I typically have between 1,500 and 2K messages in my queue on
> that machine (my hobby box), all for slow/down MXes.

Things look a lot like that for a while after an announce list
posting here, too.  I only try to measure delivery rate while
the list server is still running 150 smtp processes.

 Dan Wilder <dan at ssc.com>   Technical Manager & Editor
 SSC, Inc. P.O. Box 55549   Phone:  206-782-8808
 Seattle, WA  98155-0549    URL http://embedded.linuxjournal.com/

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