optimal dns RR's for 30 servers ?

[elia Mazzawi]

when i said 900 i mean't we didn't want to add more than 900 RR's in
our dns server. as a practical limit.

i was distracted from this task and we ended up making our RR's like
this for now.

A1 B1 D1
A2 B2 D2
A3 B3 D3
C1 B4 D4
C2 B5 D5
C3 B6 D6
C4 B7 D7
C5 B8 D8
B9 B10 D9
B11 B12 D10

the kind of set up we were hoping to achieve was,
for example now if one server here is out now we stop using the RR, so
2 perfectly good servers are idle and all servers get 10%(3/30) more
load.
i wanted a setup where if one server is out, all other servers share
the 1/30 more traffic and the dead server and all the RR's its in are
taken out.
intuitively i think this set up would have 900 RR's.