I'm obviously using the wrong search terms, the answer must be somewhere out there, so please throw some URLs at me.
I'm about to create a cluster with 2 virtual servers in the cloud, namely at Rackspace.
One for the frontend (Apache+PHP), one for the backend (presumably PostgreSQL).
Apart from pointing the database host to the another IP instead of localhost, and opening up the , is there anything else I'm supposed to learn or prepare to fully utilize this architecture?