[155616] in North American Network Operators' Group
Re: Return two locations or low TTL [was: DNS caches that support
daemon@ATHENA.MIT.EDU (Chris Adams)
Mon Aug 20 08:48:04 2012
Date: Mon, 20 Aug 2012 07:47:34 -0500
From: Chris Adams <cmadams@hiwaay.net>
To: NANOG list <nanog@nanog.org>
Mail-Followup-To: Chris Adams <cmadams@hiwaay.net>,
NANOG list <nanog@nanog.org>
In-Reply-To: <0953B8D9-ED04-48ED-ACB9-18EA4C9CB9AA@ianai.net>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Once upon a time, Patrick W. Gilmore <patrick@ianai.net> said:
> * How many applications are even aware multiple addresses were returned?
Most anything that supports IPv6 should handle this correctly, since
getaddrinfo() will return a list of addresses to try.
> * How do you guarantee sub-second failover when most apps will wait longer
> than one second to see if an address responds?
That's a bigger issue. Also, for web services, the application might
wait, but the end-user usually won't (if the site doesn't come up in a
second, they move on to the something else).
--
Chris Adams <cmadams@hiwaay.net>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.
