scatter wdsci, to by instances in various parts of the world... about syncing, then who will think? And DNS who would the shaman, if you fall something? don't forget that they only work as a round-robin.
2 servers in the M9 and M9-ENEA, heartbeat, smart gateway, which will respond and transmit the IP address to the second server if the first one falls. Value — 9-15K+rent/colo server+traffic.