Re: using zmailer for serious production

[Matti Aarnio <mea@nic.funet.fi>]

> Greetings,
> 
> 	I'm following the development of zmailer since the time
> Rayan was its author. The design is very amazing. As for now I
> work for a large internet provider in Holland and we relay/handle
> a couple hundreds of thousands emails a day. This is a very tough
> task for sendmail so I am really considering switching our major
> operations to zmailer. I looked into current version of it and it
> was quite a pleasant seen although neither properly documented nor
> commented still looks very promising and solid.

	The documentation will improve quite fast.
	Telecom Finland did hire a company specialized at technical
	documentation writing to do it, and first draft should be
	available for public review around  21st-23rd of July.
	(Before that I have had two iteration rounds.)

	I am working on all kinds of little problem people report
	to me to get the current version to stabilize -- right now
	I have done a few patches to the lattest public version
	(2.99.49p2), and should propably make them available as "p3"
	soon.

	At Telecom Finland we use ZMailer as the firewall frontend
	in between our internal mailers, and the Internet, and the
	traffic flows here are not that great -- on average 20-30k
	messages per day.

	At nic.funet.fi the daily traffic at the transport is between
	140-280k addresses (deliveries and attempts) per day. In there,
	for 28-30th of June, my quick oneliner egrep/awk/cut/whatnot
	throwaway script gave daily routing statistics as:

		msgs=3320 addrs=137991
		msgs=1135 addrs= 66862
		msgs=3146 addrs=158407

	This all while nic.funet.fi is doing its main job of feeding
	20-30 GB per day via anonymous FTP to customers.  The machine
	itself is oldish DEC 3000/900 uniprocessor (EV4) Alpha running
	at 275 MHz.

	This kind of recipient count/message ratio is abnormal, and is
	one of the reasons we see occasionally a bit slow delivery thru
	the system -- delays of 15-30 minutes in the router input queue.
	(My future main interest will be to get the router faster at its
	 script execution, and data manipulation.)

	During this month we should do a larger MTA bencmarking run
	with all kinds of systems (X.400, and non-X.400 ones).  Then
	I can perhaps tell how much ZMailer really can push, and
	compare it (at least) against sendmail 8.8.x.

>    I would like to
> hear some success stories/comments/opinions/advices regarding
> running zmailer in production environment. Needless to say our
> email operations is almost the most critical part in our business
> so should it fail a company like ours could be out of business in
> a couple of days. Sorry for being a bit noisy and thanks for your
> reactions in advance,

	Our (Telecom Finland) ISP service group is using sendmails
	at the mailbox delivery stage, because the original system
	was done with them, but that too might change.

	Occasionally some users have complained that ZMailer is "slow"
	to deliver their email -- like when it gets rapidly large
	number of messages, or when its queue is empty, and the router
	(or scheduler) is in their 20 second queue-recheck delay phase..
	Nevertheless, the router can churn happily 200k-800k messages
	per day per process, and the scheduler can push out even more.

	Sure you can have faster delivery with sendmail at light load,
	but try to saturate your system.  Sendmail kills it, just like
	Ethernet can't give full 10/100 Bps for multiple users, and
	FDDI can.  These are just fundamentally different technologies.

	... huh, I begin to sound like a marketroid ...
> 							alexis
> -- 
> 		Yesterday dont matter when its gone

/Matti Aarnio	<mea@nic.funet.fi>	(FUNET archive admin)
		<matti.aarnio@tele.fi>	(working at Telecom Finland)