[119163] in North American Network Operators' Group
Re: What DNS Is Not
daemon@ATHENA.MIT.EDU (bmanning@vacation.karoshi.com)
Sun Nov 8 19:48:45 2009
Date: Mon, 9 Nov 2009 00:46:48 +0000
From: bmanning@vacation.karoshi.com
To: David Andersen <dga@cs.cmu.edu>
In-Reply-To: <85B2BEB6-8E55-4CEF-B3AB-3BC19589B7EB@cs.cmu.edu>
Cc: bmanning@vacation.karoshi.com, NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Sun, Nov 08, 2009 at 07:42:18PM -0500, David Andersen wrote:
>
> On Nov 8, 2009, at 7:30 PM, bmanning@vacation.karoshi.com wrote:
>
> >On Sun, Nov 08, 2009 at 07:17:16PM -0500, David Andersen wrote:
> >>
> >>"Our trace-driven simulations yield two findings. First, reducing the
> >
> > -----------
> >> -Dave
> >>
> >
> > a simulation is driven from a mathmatical model, not real world
> > constructions.
>
> Hi, Bill -
>
> The paper is worth reading.
>
> "The paper also presents the results of trace-driven simulations that
> explore the effect of varying TTLs and varying degrees of cache
> sharing on DNS cache hit rates. "
>
> emphasis on *trace-driven*. Now, you can argue whether or not their
> traces are representative (whatever that means) -- they used client
> DNS and TCP connection traces from MIT and KAIST, so it definitely has
> a .edu bias, iff there is a bias in DNS traffic for universities vs.
> "the real world", but to the extent that their traces represent what
> other groups of users might see, their evaluation seems accurate.
>
> -Dave
I'm not debating the traces - I wonder about the simulation
model. (and yes, I've read the paper)
--bill
