Re: [dnsop] DNS Anycast revisited

[Todd Vierling <tv () duh org>]

On Tue, 3 May 2005, Rodney Joffe wrote:

> > > If you check, I think you'll see that he actually said "ultradns's
> > > anycast for .ORG is completely coherent".
> >
> > And last time I checked -- on this list, mind you -- it certainly was not.
>
> If you want to be taken seriously, perhaps you might want to research the
> use of the term coherency in terms of DNS.

> Hint: It doesn't mean that one node responds and another doesn't.

<feedback loop="trollbait">
It certainly breaks coherency in my mind when one query host receives
SERVFAIL for a while, then nothing at all, but another query host is
receiving records that the first query host *should* have seen.
</feedback>

After all these years, I should know better than to feed back the bait.
Maybe it's just fun to do.  :)

That said, I'll credit you for catching my brain fart.  I read right past
'coherent' in vix's text and saw the phrase '"good" anycast' in relation to
the .ORG zone.  It was not technically a *coherency* flaw to which I
referred, but rather a fundamental *architecture* flaw.  (It's too bad that
the architectural flaw was never really discussed, or for that matter
subjected to a mea culpa and/or public postmortem.  But I suppose that is
the pride/ego component of running such a large zone -- even one intended
for the "public interest".)

I wrote and maintain a query host deterministic, but inter-site coherent,
anycasted DNS server for my $orkplace, so don't presume to tell me what you
think I know.  It only makes you look like a holier-than-thou ass [again].
Feel free to feed the trolls elsewhere, though, if you wish; it can be fun
to watch.

-- 
-- Todd Vierling <tv () duh org> <tv () pobox com> <todd () vierling name>