In 2008, Paul M. Jones announced the release of an SQL adapter that allows Solar users to connect to master/slave database installations. My first reaction was: Great! This will inspire other FOSS developers to create similar components. And guess what, it did. I wrote my own ReplicationAdapter. It's not great, but it's flexible enough to support the most commonly used replication scenarios:
He gives examples of how it can be used for single-master replication, multi-master replication and how the adapter can be used to create a distributed caching system for database connections. A brief Zend Framework-based example is also included.