[Mailman-Developers] Mailman with sendmail = performance bottleneck

[J C Lawrence]

On Tue, 21 Nov 2000 18:04:07 -0600 
Bob Tanner <tanner@real-time.com> wrote:

> I have to say I am very disappointed at mailman's performance with
> sendmail.  Especially qrunner and how it works.

This is not a sendmail problem.  Questionably it is a Mailman
problem in that qrunner as currently architected is not terribly
scalable.

> I am running sendmail with 10 queues, but it looks like mailman
> only understands and utilizes 1 queue. It also looks like qrunner
> is single threaded AND multiple instances cannot be running at the
> same time.

True.

> This lends itself to a very slow delivery system.

Only if your MTA is configured to make it so.  Example: Delivering
100 messages (1K members with 10 RCPT_TOs per message) via qrunner
to Exim or Postfix takes just under 2 seconds here.  Admittedly this
is a fast machine.  Additionally the local MTA is configured to not
do name lookups on local deliveries, and, of course, I'm running a
cacheing name server locally.

> What sucks is qrunner just tries to deliver each message one at a
> time. If message 5 takes forever on the rcpt to: command (for
> example), no other messages deliveries are attempted because
> qrunner sits on message 5 until it times out.

Translation: You are doing name lookups on messages delivered via
SMTP from the localhost.  There's not much reason for this.  Turn it
off.

> Will mailman support multiple "qfiles" directories in the future?

Not for v2.0.  After, yes.  No designs are finalised.

-- 
J C Lawrence                                       claw@kanga.nu
---------(*)                        : http://www.kanga.nu/~claw/
--=| A man is as sane as he is dangerous to his environment |=--