1) What is an acceptable size range of objects that should be attached to a session? If I attach an object that can be 5k, and I have 10k valid sessions at any given time, that's 50MB of memory which seems acceptable to me. Is that a valid way to approach the issue, or are there other significant concerns?

2) This is probably a dumb question, but if I attach an object to a session with a 2 week lifetime, can I access the attribute as though it were in memory for the whole duration of the session?

3) Is there any reason NOT to always persist session information to a DB?