High-performance centralized PHP session storage

Question

My application can store up to dozens or even low hundreds of KB of data in the session. I'm currently storing PHP sessions in MySQL blobs, and traffic volume is now putting session-related queries on the database around 25-75 per second. It's causing some problems.

Is there a centralized storage option for PHP sessions of this size that will perform well? I'd prefer to avoid sticky sessions at the load-balancer level if possible for other performance reasons. I can try to reduce the session size, but regardless I'm going to need this information on most requests, so I'm going to have to stash it somewhere.

Answer 1

Scache is ideal for that. You can probably split your session data to smaller parts, some might even be cacheable to all sessions and so on. Scache has api for all that.

There's nothing bad in big session data, it's bad only if you store it to $_SESSION.

Answer 2

memcached is always a favorite option.

The memcache PHP extension helpfully comes with a session handler that will store sessions with memcached.

Answer 3

Zend's own session cluster daemon:

http://www.zend.com/en/products/server-cluster-manager/high-availability