Re: P5EE Sessions

Gunther Birznieks writes:
> One thing I would disagree with on Rob's thing below is that a session is 
> just a is just a web browser instance associated with a set of data. 
> Sessions can be more than just passed over a single browser. You can always 
> have a session that is shared amongst many users to cache data that you 
> would like to eventually expire when the user load goes down for example.
>
> A session, is, well... a session. :) How you manage those sessions (user 
> cookie, form variable, or across a larger set of users as cache is up to 
> your session manager code IMHO...:)

I think we should differentiate between data caching and sessions.
A data cache is an associative memory, which is probably content
addressed.  Sessions is an associative memory, which is user/browser
addressed.  The former does not need to be garbage collected, but
sessions do.  The system can run without a cache, but from the way
sessions have been described (esp. your eloquent description of tomcat
cache problems :), they need to exist for the system to function.
Caches for performance reasons are critical to large-scale
applications.  Sessions for programming convenience reasons are often
detrimental to large-scale systems.

Rob