[dns-operations] cache and subnet option

[Florian Weimer]

On 04/20/2017 09:34 AM, Randy Bush wrote:
>>> [ to my naïve eye, issuing a second query would seem to have, shall
>>>    we say, interesting scaling properties ]
>> It does and that is why it usually better to get the distribution
>> effect by placing resolvers near the edge of the network.
> 
> is that not the same increase in global query load, just eminating from
> more resolvers?

It's worse because those resolvers would have separate caches for 
infrastructure DNS records.  I don't think those are treated as 
subnet-dependent by a single, shared cache.

Thanks,
Florian