ASP.NET Session Scope: where can it be accessed from?

Question

This seems trivial, but I've never had to worry about it before and my Google skills are failing me. How far-reaching is the in-process session bucket for ASP.NET/IIS6, in the sense that you can call Session["whatever"] and get the same value back? Obviously it can't stretch across different servers or application pools (I think). What about different web sites in the same application pool? Can those two see each other's session variables for a user? What about two different virtual directories each with their own web.config?

Thanks!

Answer 1

Obviously it can't stretch across different servers

Sure you can. This MSDN Article has more details.

Answer 2

It can stretch across servers in a farm if the asp.net session is stored in the database.

Perimeter of session is strictly within the one app domain for security reasons

Answer 3

This sounds like you would be better off storing a database value than storing it in a In-Proc session[""]. If you have a state server then the session can be accessed across all machines that use the same state server. In-Proc is just what it says. It's stored In the Process of that single computer.

Answer 4

If you wanted to share Session across applications with a SQL Server backend, there's an article on how to do that.

Answer 5

AFAIK the in-process session has an AppDomain scope, so no, two web applications running in the same pool cannot share an in-process session. Actually the name "in-AppDomain" would be more appropriate.