Fwd: GeoIP and maintaining high availability

[Dave Knight]

Sending again, this time from an account actually subscribed to the list, doh :)

> From: Dave Knight <dave.knight at icann.org>
> Date: July 9, 2010 4:39:38 PM EDT
> To: Tomasz Chmielewski <mangoo at wpkg.org>
> Cc: "bind-users at lists.isc.org" <bind-users at lists.isc.org>
> Subject: Re: GeoIP and maintaining high availability
> 
> On 2010-07-09, at 4:30 PM, Dave Knight wrote:
> 
>> Hi Tomasz,
>> 
>> On 2010-07-09, at 10:26 AM, Tomasz Chmielewski wrote:
>> 
>>> Hi,
>>> 
>>> I'm about to set up bind with GeoIP patches.
>>> 
>>> What I'm not sure, is how do you guys handle high availability?
>>> 
>>> Suppose I have zones for Americas and Europe, and a destination server in Europe dies - how do you handle it so that new (i.e. web) requests hit American servers only?
>>> 
>>> Set TTL to low values (i.e. 10 minutes max) and reconfigure the zones if European servers are down? Something else?
>>> 
>>> I assume typical hosting, without access to sophisticated network settings, like BGP.
>> 
>> I think that you're confusing two issues. 
> 
> On second read of your post I see that it's me that's confusing issues :)
> 
> You'll use GeoIP to direct European users to a European web server, and Americans to an American one, etc. If one, or the other is down you want to direct all users to the one that is up. 
> 
> A low TTL on the specific RRSet, ie
> 
> www.example.com.	600	A	192.0.2.1
> 
> combined with a script running on the nameserver which checks that the target web server is up and talking sense, and modifies that RRSet if it is not... 
> 
> sounds like what you want.
> 
> Sorry for the noise.
> 
> dave