Sites across Multiple servers

[eluser]brianw1975[/eluser]
I wouldn't worry about db replication to begin with; especially if you are using the caching... I'd worry about setting up a load balancer first.

You'd basically have 1 DB server and 2 Apache servers with a load balancer that will direct traffic accordingly.

The load balancer can also keep tabs on the DB server and direct traffic to a "Site down for maintenance" page in case the DB has crashed or whatever. I've not set up a load balancer myself, my last employer had one in place when i started there; but the idea is pretty straight forward (and should be able to be set up on the primary web server.