With the recent release of PHP 5.1.0 RC1, I have noticed a release of Zends Session Clustering that their marketing team had mentioned was due for a release (I assume this to have been delayed). Whilst I have been using standard file based session’s for an on going project, I hit an unusual stumbling block with a very expensive operation to create sessions in a clustered enviroment. Unfortunately I never did find the cause as to why session start caused such overhead, however this was ironed out. It will be interesting to see how Zends Session Clustering would work inline with this project.

Reading through some documentation i’m a little apprehensive as to Zends solution for Session Clustering.

In this module sessions “reside” on the server where they were first created. These sessions are subsequently delivered to other servers in the cluster, by having the alternate server request the session data from the original server. This means a fully distributed solution – delivering high performance, linearly scalable solution utilize existing hardware investment, while ensuring the ability to continue growing.

Zends Session Clustering utilizes a daemon to allow clustering of sessions, currently our in our enviroment sessions are persisted to one dedicated server, the master.

Zend Session Cluster