Which technology is an application of MSDP, and provides load balancing and redundancy between the RPs?

With Anycast RP you place the same IP address on multiple routers (usually configured on loopback), and advertise that address as the RP address for the PIM domain via BSR, AutoRP, etc. MSDP allows the two routers acting as Anycast RPs to tell each other about all multicast sources to avoid a disjoint multicast domain.