On PHPMaster.com today there's a new tutorial showing you how to store your application's sessions in Redis, a key/value store known for its flexible nature and speed.
PHP's default handling of session data is probably sufficient for most applications, but sometimes a project will demand a different storage approach. Luckily, the session handling routines can be overridden either by a series of functions (in older versions of PHP) or a class with methods (in newer versions) which handle various aspects of session management. In this article we'll learn how to create a custom session handler which implements PHP's SessionHandlerInterface interface and stores the session data in a Redis database.
He talks some about the reasoning behind using something more than just the normal PHP session handling (including the flexibility it provides). He covers some of the basics of the session handling functionality and covers how the data itself is stored. Finally, he gets to the actual class - a Redis-specific handler that implements the SessionHandlerInterface interface.