Page #58 (Chapter 7 - Controlling Program Flow)

	Chapter 8 - Maintaining State in IIS Applications
	Visual Basic Developers Guide to ASP and IIS
	A. Russell Jones

Copyright 1999 SYBEX Inc.

---

	Chapter 8: Maintaining State in IIS Applications

	Overview

	Maintaining state means keeping track of all the information your application needs to know about a specific user, either during a single session or between multiple sessions. Examples of the kinds of information you may need to know are:

	•		What is the user's name?

	•		Has the user signed on?

	•		Has the user seen the previous page?

	•		Has the user properly filled out a form at some previous stage?

	•		Is the user waiting for a response from the application?

	Longer term, you might want to be able to answer more complex questions, such as:

	•		Has this user purchased any other product like <this> from us during the past year?

	•		Which pages in the application has this user never seen? How might you best route them there?

	In essence, maintaining state is the process of associating information with a specific user. This is the biggest single problem you're likely to have with your Web applications, and how you solve it depends, or should depend, on several factors:

	•		The number of users you expect to access your application simultaneously

	•		The size and speed of your server

	•		The efficiency of your pages

	•		The amount of information you need to store to maintain state for a single user

	In this chapter, I'll show you several options for maintaining state in WebClass applications and discuss the advantages and disadvantages of each.