Static fields vs Session variables

Question

So far I\'ve been using Session to pass some variables from one page to another. For instance user role. When a user logs in to the web application the role id of the user i

Answer 1

No, using static variables for this is not the way to go:

• If your AppDomain is recycled, all your static variables will be "reset"
• Static variables don't scale horizontally - if you load-balance your application, a user who hits one server then a different one won't see the data store in the static variables in the first server
• Most importantly, static variables will be shared by all access to that server... it won't be on a per-user basis at all... whereas from your description, you wouldn't want user X to see user Y's information.

Fundamentally, you have two choices for propagating information around your application:

• Keep it client-side, so each request gives the information from the previous steps. (This can become unwieldy with large amounts of information, but can be useful for simple cases.)
• Keep it server-side, ideally in some persistent way (such as a database) with the client providing a session identifier.

If you can use load-balancing to keep all users going to the same server, and if you don't mind sessions being lost when the AppDomain is recycled¹ or a server going down, you can keep it in memory, keyed by session ID... but be careful.

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¹ There may be mechanisms in ASP.NET to survive this, propagating session information from one AppDomain to another - I'm not sure