DNS-cache with custom gTLDs

[Drunkard Zhang]

I got 4 DNSs doing recursive resolution, which splited into 2 groups,
and a couple of dns caches. Each group of recursion DNS using their
own net link, which is different.

Here's problem: I want a dns-cache to use one group of recursion DNS
as their forwarders, and use another group as backup. ( I have to,
because 2 groups of recursion DNS get different results, and sometimes
one of them can't resolves, while another can. ) All solution I can
find out is "forward first" to one group, and use all 2 groups as
gTLDs, is this __safe__?

Is there any other solution I can hack?


Another problem: there's a lot of resolution on dns-cache querying
a.root-servers.net, is it safe that i hijack a.root-servers.net to my
own DNS? If it's safe, I can cut down queries to a.root-servers.net by
millions of times per hour.

Look forwarding to your kind responses :-)