mailing list archives
Re: DNS caches that support partitioning ?
From: Michael Thomas <mike () mtcc com>
Date: Fri, 17 Aug 2012 13:41:04 -0700
On 08/17/2012 01:32 PM, valdis.kletnieks () vt edu wrote:
On Fri, 17 Aug 2012 15:32:11 -0400, Andrew Sullivan said:
On Fri, Aug 17, 2012 at 04:13:09PM -0000, John Levine wrote:
The application I have in mind is to see if it helps to keep DNSBL
traffic, which caches poorly, from pushing other stuff out of the
cache, but there are doubtless others.
If it's getting evicted from cache because other things are getting
used more often, why do you want to put your thumb on that scale? The
other queries are presumably benefitting just as much from the caching.
I think John's issue is that he's seeing those other queries *not* benefiting
from the caching because they get pushed out by DNSBL queries that will likely
not ever be used again. You don't want your cached entry for www.google.com
to get pushed out by a lookup for a dialup line somewhere in Africa.
If the dnsbl queries are not likely to be used again, why don't they
set their ttl way down?
In any case, DNSBL's use of DNS has always been a hack. If v6
causes the hack to blow up, they should create their own protocol
rather than ask how we can make the global DNS accommodate
their misuse of DNS.