NYCPHP Meetup

[Daniel Krook]

> The question is:  how much data should I feel free 
> to store in a session?  As much as I want?  Or not?

The instinct here is always to minimize what you are storing in the 
session on the server (in addition to what you're sending back and forth 
to the client in the form of cookies as Hans mentioned), so that you don't 
overload the file system.  I saw some example a few months back about 
about the space required by an application that had 20k of session data on 
the file system x number of users x 20 minute time out which brought the 
space needed to 2GB for a modest amount of users.

To determine how much you can store in the session, I found this passage 
to be the best test (even though it's a WebSphere doc it applies to web 
apps in general):

ftp://ftp.software.ibm.com/software/dw/wes/pdf/0207_garratt.pdf (p. 25)

"The best solution I have found to this problem is load testing the 
application in an
environment that is as close as possible to the anticipated production 
environment. Once
functional correctness has been verified, load testing provides the best 
opportunity to
discover latent bugs in the system. These bugs range from inadequate disk 
space for logs
(or inordinately large amounts of trace) to session persistence problems 
related to
improper session-related coding techniques (a very common source of 
problems). Load
testing in general will quickly flush these problems out."





Daniel Krook, Advisory IT Specialist 
Application Development, Production Services - Tools, ibm.com

Personal: http://info.krook.org/
BluePages: http://w3.ibm.com/bluepages?searchcnum=9A9796897