[Serusers] question about relay

Hi, I am using SER as a an entry point for the requests from the network and every request from the network is being relayed to another ( clusterized ) SIP server ( not a SER ) with multiple IP addresses in DNS. The server is running on 4 machines, any number of which can be down at any moment of time. Suppose, the DNS name is "sip.myserver.com". The incoming requests from the network have SER as host:port of RURI.. I was trying to relay the request using t_relay_to_udp("sip.myserver.com", "5060"), but all requests would always go to the same IP. A question: Is there any way to make SER relay requests to those IPs in round-robin manner? Or can I force SER to make DNS requests before processing each request? Another problem related to this situation, if the SER relays all requests to the same IP, and the server represented by that IP goes down, I have 100% call failure. Is there any way to avoid that? thanks, Sergei