Re: Return two locations or low TTL [was: DNS caches that support partitioning ?]

["Patrick W. Gilmore" <patrick () ianai net>]

On Aug 20, 2012, at 10:07 , "Dobbins, Roland" <rdobbins () arbor net> wrote:
> On Aug 20, 2012, at 5:56 PM, Patrick W. Gilmore wrote:
>
> > My question above is asking Mark how you guarantee the user/application selects the A record closest to them and 
> > only use the other A record when the closer one is unavailable.
>
> I understand - my point was that folks using a GSLB-type solution would generally include availability probing in the 
> GSLB stack, so that a given instance won't be included in answers if it's locally unavailable

How does that allow for a long TTL?  If you set a 3600 second TTL when the DC is up, and the DC goes down 2 seconds 
later, what do you do?


> (obviously, the GSLB can't know about all path elements between the querying resolver and the desired server/service).

Says who? :)

-- 
TTFN,
patrick