[Mailman-Developers] Re: To VERP or not to VERP?

[Norbert Bollow]

Chuq Von Rospach <chuqui@plaidworks.com> wrote (in two different
messages):

> >  Currently I send it about
> > 10000 messages that it breaks up one by one using. I don't know about 
> > memory
> > or disk issues there, but 130 000 * 10k = 1.3 Gbytes on disk:
> 
> It's a problem. network and disk are (IMHO) the two big performance 
> issues in delivering e-mail (at least the two under your control. The 
> third is the speed at which receiving machines will accept messages, but 
> you can't buy everyone in the universe faster e-mail servers...)
> 
> the amount of disk it takes isn't an issue (within reason) -- remember, 
> it's going to start sending right away, so message will be gone out of 
> the queue. You don't queue it all up and then start delivery.

I think it is certainly an issue - the disk partition with the
mailqueue must be big enough that even if there are network
problems at the time when all your digests are mailed out, all
the digests can be stored without problem.

This is not a problem with the qmail trick which I've explained
at http://mailman.cis.to/qmail-verh/ because there only one copy
of the message is stored in the mailqueue, which is then
customized by means of pattern substitutions on-the-fly when
qmail talks SMTP with the receiving mailservers.

But if Mailman customizes messages and passes one message per
recipient to the MTA, then you had better make sure that you
have a big enough mailqueue partition.

> that I'm calling the "army of smurfs" design. I'm going to be buying 
> lots of small/fast/cheap boxes, and not going to try to try to keep 
> making that single monolithic machine do incrementally more.

Ezmlm-idx has some really neat features for that, which I'd love
to see implemented in Mailman.

Greetings, Norbert.

-- 
Norbert Bollow, Weidlistr.18, CH-8624 Gruet (near Zurich, Switzerland)
Tel +41 1 972 20 59     Fax +41 1 972 20 69      nb@freedevelopers.net