Scalability Rules: 50 Principles for Scaling Web Sites

10. Avoid or Distribute State

The state that we hate the most can’t be found on a map of the United States or any other country for that matter. The state we hate most is persistent state (and session information) held within the application of an Internet site. And why, you might ask, do we hate state so? Session and state destroy the ultimate value promised by multitenancy within Internet (SaaS, commerce, and so on) applications. If we must keep great amounts of data associated with a user’s interactions at any given time, then we can house fewer users on any given system at any given time. In the desktop world, we rarely needed to be concerned with this as we often had a lot of power and memory available for a single user at any given time. ...