Anybody stepping up from a single MySQL server to any kind of cluster made of MySQL servers (MySQL Cluster, MySQL Replication, home-grown sharding and 3rd party) has to load balance connections. Different approaches are compared to the free and open source PECL mysqlnd_ms PHP mysql plugin: application based, proxy based and driver based. It turns out that a driver based solution makes a very good system architecture. Its fault tolerant, it scales well, it requires no or little application changes and its a natural fit for PHP deployments. And, of course, it works with all PHP MySQL applications running on PHP 5.3 or newer using any of the three PHP MySQL APIs (mysql, mysqli, PDO_MySQL). Check it out.... in the slides and download PECL mysqlnd_ms for a test drive. Even if you don't go for PECL mysqlnd_ms this presentation is helpful as it gives hints on choosing an architecture.