The Goal of This Book

This book gives you the tools and techniques for building high-performance Web applications with ASP.NET. In particular, it focuses on the often-neglected topics of performance monitoring and Web stress testing. Web applications are required to perform well under highly variable load levels. If you are lucky ”and live on a distant planet in a galaxy far, far away ”then your Web application will be overpowered for the actual load it experiences and the application performance will be outstanding from Day 1 on. But if you are like the rest of us, then your Web application will experience variable loads and frequent overexertion, and you will need to work through the painful process of tuning and optimizing the application to perform well under its target load.

To this end, we pay particular attention to the tools available to developers to quantify and monitor performance issues and to diagnose performance problems more quickly. As noted earlier, today's sophisticated Web users expect high performance and will quickly turn hostile to an application (and a developer!) that cannot provide the high performance they demand.

We also pay attention to design decisions, meaning the technology choices you make when you have several options from which to choose. For example, when you choose to use a DataSet over a DataReader for accessing data, you are making a specific design decision, whether you realize it or not. With the former, you are choosing an object that enables you to manipulate a disconnected DataSet. With the latter, you are choosing an object that provides a lightweight, read-only data stream. The implications of this design decision can be profound, both on performance and on the code's complexity.

A more complex scenario is how to persist application-level information so that it is available to multiple requests from multiple users. Do you use the standard Application object? Do you use the new cache object? What is the difference between them, and how do you choose the best technology for this scenario? In other words, what is the most appropriate design decision?

We spend the entire book reviewing these questions in one form or another. But at a high level, making a design decision is a two-step process. First, you have to be familiar with how to implement each of the options. Second, you have to understand the implications of choosing one option over another. Many books cover the first step well by showing you how to code with various objects and how to implement certain approaches. But few books provide an in-depth discussion on the implications of one approach over another. This book digs deep into ASP.NET technology. By understanding advanced features, you will realize new, more optimal ways to write your ASP.NET applications.

The bottom line is that you have to be happy with your design decisions because you will have to live with all of the implications, even those you have not yet considered .

This is the perfect lead-in to restating the goal of this book before moving on to the good stuff. Simply put, this book helps you build high-performance ASP.NET Web applications. The way this book gets you there is by the following:

• Educating you about the tools and techniques for programming high-performance ASP.NET applications

• Educating you about the tools and techniques available for you to monitor and optimize the performance of your ASP.NET application

• Providing you the in-depth information you need to better understand ASP.NET technology and thereby make optimal design decisions

Note

ASP.NET provides superior performance compared to classic ASP. Furthermore, the latest independent performance benchmark numbers show that ASP.NET performs significantly better than equivalent Java 2 Enterprise Edition (J2EE) applications written in Java. For more information on this benchmark study, see ".NET Wins New Benchmarks" on MSDN at http://msdn.microsoft.com/library/default.asp?url=/library/enus/dnbda/html/bdasamppet.asp .