[155604] in North American Network Operators' Group
Re: DNS caches that support partitioning ?
daemon@ATHENA.MIT.EDU (Chris Woodfield)
Sun Aug 19 16:01:24 2012
From: Chris Woodfield <rekoil@semihuman.com>
In-Reply-To: <76D701C9-00F6-4EC4-A618-2D6E53664AAB@ianai.net>
Date: Sun, 19 Aug 2012 13:00:49 -0700
To: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
What Patrick said. For large sites that offer services in multiple data =
centers on multiple IPs that can individually fail at any time, 300 =
seconds is actually a bit on the long end.
-C
On Aug 18, 2012, at 3:43 PM, Patrick W. Gilmore <patrick@ianai.net> =
wrote:
> On Aug 18, 2012, at 8:44, Jimmy Hess <mysidia@gmail.com> wrote:
>=20
>> And I say that, because some very popular RRs have insanely low TTLs.
>>=20
>> Case in point:
>> www.l.google.com. 300 IN A 74.125.227.148
>> www.l.google.com. 300 IN A 74.125.227.144
>> www.l.google.com. 300 IN A 74.125.227.146
>> www.l.google.com. 300 IN A 74.125.227.145
>> www.l.google.com. 300 IN A 74.125.227.147
>> www.l.google.com. 300 IN A 74.125.227.148
>=20
> Different people have different points of view.
>=20
> IMHO, if Google losses a datacenter and all users are stuck waiting =
for a long TTL to run out, that is Very Bad. In fact, I would call even =
2.5 minutes (average of 5 min TTL) Very Bad. I'm impressed they are =
comfortable with a 300 second TTL.
>=20
> You obviously feel differently. Feel free to set your TTL higher.
>=20
> --=20
> TTFN,
> patrick
>=20
>=20
