*BSD News Article 85363


Return to BSD News archive

Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.Hawaii.Edu!pith.uoregon.edu!hunter.premier.net!www.nntp.primenet.com!nntp.primenet.com!su-news-hub1.bbnplanet.com!news.bbnplanet.com!cam-news-hub1.bbnplanet.com!news.mathworks.com!uunet!in2.uu.net!194.217.216.129!oaktree.co.uk!jon
From: jon@oaktree.co.uk (Jon Ribbens)
Newsgroups: comp.mail.sendmail,comp.mail.smail,comp.unix.bsd.freebsd.misc
Subject: Re: Sendmail vs. Smail...
Date: 23 Dec 1996 01:19:06 GMT
Organization: Oaktree Internet Solutions Ltd.
Lines: 33
Message-ID: <slrn5brnga.4fs.jon@black.oaktree.co.uk>
References: <57tf61$gq7@raven.eva.net> <598tvm$t0h@ezekiel.eunet.ie> <1996Dec1821.08.45.5092@koobera.math.uic.edu> <59bjh9$fl1@ezekiel.eunet.ie> <1996Dec2000.07.45.5990@koobera.math.uic.edu>
NNTP-Posting-Host: black.oaktree.co.uk
X-Newsreader: slrn (0.9.0.0 (BETA) UNIX)
Xref: euryale.cc.adfa.oz.au comp.mail.sendmail:35442 comp.mail.smail:2752 comp.unix.bsd.freebsd.misc:32866

D. J. Bernstein <djb@koobera.math.uic.edu> wrote:
> > considerably more IP traffic
> 
> False. Measurements have shown at three separate sites that switching
> from sendmail to qmail _reduces_ traffic.

But that's not what he said, is it? This discussion is about
grouping RCPTs versus not grouping them, and changing from
sendmail to qmail will change much more than just that.

I *think* your argument is that because you have to wait
for a reply after the 'RCPT TO' command, lots of them
cause the mail to be very slow if there is a large RTT,
whereas if you use many SMTP transactions at once then
the long RTT waits are in parallel rather than in serial?

Presumably you would therefore agree that RCPT grouping
is much preferable if ESMTP pipelining is available?

And you would also agree that, in the absence of pipelining,
a dynamic system which tried to guess how many RCPTs
should be grouped in a single transaction before the
grouping becomes detrimental would be better than either
never grouping or always grouping?

Cheers


Jon
____
\  //    Jon Ribbens    // 10MB virtual-hosted // www.oaktree.co.uk
 \// jon@oaktree.co.uk // web space for 49UKP //