On Thu, 08 May 1997 19:30:38 -0400 Brad Knowles <[log in to unmask]> said:
>Your message dated: Thu, 08 May 1997 15:51:02 PDT
>
>> Now if only something could be done about the a.mx....
>
> You mean pointing MX RRs at CNAME RRs?
>
>(...)
>
> In the meanwhile, more and more sites are depending on pointing MXes
>at RRs, because that's the only way they can list a suitably small set
>of MXes for their domain (along the recommendations of
>draft-myers-mail-largesite-00.txt), while still making use of, and doing
>decent load balancing across, their entire set of MXes. In AOL's case,
>that's now almost sixty machines.
Well, of course you wouldn't have this problem to begin with if you
didn't need to have sixty machines to process your 5M daily SMTP
transactions. Have you seen Rob Kolstad's work on multi-million daily
deliveries on a simple Pentium with sendmail? Clearly you don't need
SIXTY machines when a handful of Pentiums can do it!
Sorry, I couldn't resist :-) But setting jokes aside, the front end
approach I was describing would allow you to cut down the number of
incoming mail servers to 3-4 larger boxes that don't fork() every time
there is a new connection and thus only burn a minority of their
resources on overhead, and your customers wouldn't be cut off from sites
that do not use CNAMEd MXes. Of course I do realize that your position on
this is probably that people whose mail software cannot handle MX to a
CNAME are out of luck and evil and need to upgrade, but what can I say,
like most little mainframe boys I get lost in the woods and cry for my
Mommy whenever my users have a problem that impacts their everyday
business and my boss orders me not to solve it for them because they are
not important. Ironically the MTA I am using does not handle CNAMEd MXes
and I lost mail when you made that change, however I was able to solve
the problem quickly by source-routing (!) AOL.COM through another MTA
that does handle this. So if my MTA had followed RFC1123 and ignored
source routes as you advise, I would have been totally out of luck and my
everyday business activity would have been impacted. And AOL's, to a
lesser extent, because they run one of the largest LISTSERV sites in the
world and guess what, from time to time they badly want to be able to get
e-mail from me in the middle of the night, except it wouldn't have worked
and I don't give my home phone number to customers, PERIOD (I've been
there before, thank you very much, in fact as a double safety I connect
my phone to a modem when I am not using it, this way people can't call me
even if someone were to inadvertently leak my number and it ended up as
the primary 24h LISTSERV contact in a major site's operations room). FYI,
LISTSERV.AOL.COM has a total membership of 1,379,405 (second only to
CNET).
Eric
|
