Weighted random load balancing
Weighted random load balancing completely ignores performance. It therefore gives very accurate load balancing, but at a cost of potentially sending some users to a data center that is far from the optimal choice for performance. If precise load balancing is more important than any other consideration, weighted load balancing is a good choice.
Because the answers returned by weighted random load balancing are computed randomly, without regard to the identity of the requester, it is also a good choice if you need to balance traffic that is generated by only a small number of client nameservers.
Weighted random load balancing does not use nameserver demand estimates.