On Sun, Jul 23, 2000 at 10:06:57AM -0700, John White wrote:
> On Sat, Jul 22, 2000 at 12:45:57PM -0700, [EMAIL PROTECTED] wrote:
> > o DNS overhead is not counted
>
> I'm still not clear why this isn't counted. I mean, it -is-
> part of the traffic, is it not? Is it your contention that
> there's no difference in the dns traffic between the two
> methods?
Ok, you can beat every horse to death ;-)
Then you can't use (qmail) logfiles for calculation, but you have to use
IP traffic and count e.g. retransmits as well. With a congested line due to
opening 50 connections the packet loss and retransmits may well become
a significant factor as compared to a single session transfer.
Also DNS traffic is "relative". I run (caching) DNS servers on our
mailservers that use our "real" DNS servers as forwarders. On which point
of the system do you start counting the overhead? Also DNS is very hard to
calculate in this setup. A record that is now in the cache and is only a
host away may expire in 2 seconds and be retrieved from the "other end" of the
net and a record that is not in the cache now, will be 1 second later
and stay there for a resonable period of time.
(A german computer magazine tried to measure the quality of ISPs by
DNS response times. Very easy to fake ... Check what DNS lookups they
do a make sure that the records are in the cache of the DNS all the
time. If a competitor has to freshly get that record he'll loose.
After explaining the situation they dropped the tests ;-))
I am personally - though I love numbers and statistics - very sceptical
about the results that any non-complex test system will reveal as opposed
to a real life operating production mail system on this matter.
\Maex
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