On prowebdeveloper.info, Marcel Esser has posted the first in a series of articles looking at functionality to reduce database load in applications, specifically those using secure client-side sessions.
Scaling web applications is easy. Generally, if a web application is designed to store all of its session information in a database, it can be easily scaled by adding more servers in a load-balanced setup. This is tried and true, and it works very well - until your database server runs out of capacity.
He lists the common ways most developers solve this problem (four of them) but notes that thay are more of a temporary solution rather than a long-term fix. Instead, he outlines what the requirements for a library to correctly handle the connections should be and explains how each of them would be implemented. He's been following this kind of mentality in the development of his own package - proWebComponents.