Re: [dnsop] DNS Anycast revisited (fwd)

["Paul G" <paul () rusko us>]

----- Original Message ----- 
From: "Dean Anderson" <dean () av8 com>
To: "Mark Boolootian" <booloo () ucsc edu>
Cc: <Nanog () merit edu>
Sent: Tuesday, May 03, 2005 6:33 PM
Subject: Re: [dnsop] DNS Anycast revisited (fwd)


> On Tue, 3 May 2005, Mark Boolootian wrote:
>
> > > Note the nonsense about anycast being "completely coherent".
> >
> > If you check, I think you'll see that he actually said "ultradns's
> > anycast for .ORG is completely coherent".
>
> There seems to be no possibility for anycast to be "completely coherent",
> so ultradns' anycast couldn't be "completely coherent" either.  But Vixie
> mentions it to respond to comments by others about Ultradns' particularly
> pervasive use of anycast.

it may not be possible to make every service *consistent*, but it is
perfectly possible to make it coherent (i'm talking about coherency of
copies of a shared resource). i'm curious to see how you can substantiate
this claim, since any backend which supports distributed transaction
semantics will give you this. i can't comment on the veracity of paul's
statement comme applique ultradns, since i'm not familiar with how they do
things, but that doesn't change the fact that you've just made a statement
which appears blatantly false to anyone with any distributed systems
experience.

-p

---
paul galynin