[SR-Users] Registration replication

Hello, I'm currently working on a HA setup with geographically separated proxies. Each proxy is in a different data center with an MPLS link between them. The proxies access a locally connected PostgreSQL database that is replicated from a master in the primary data center. Note that the replicated dbs are read only. Everything works great for read only queries but registrations seem to pose a problem as they must use the primary db directly to deal with the writes. If I set userloc to db mode 2 the secondary proxies wipe out the entries in the database. If I use db mode 3 everything works great but all of the secondary proxies must use the primary database directly and a network link failure will cause a service disruption. Is there any way I can use separate read and write databases without p_userloc? Is there a better way to replicate registrations maintaining availability and scalability? And advice is appreciated. Thanks, Spencer Connected by DROID on Verizon Wireless