Testing, Piloting, and Going Live

Before you deploy Windows 2000 with IIS 5.0 on your Web server computers, it is very important that you test your proposed design in an environment that simulates real-world scenarios as closely as possible. Not only does this help you find problems with your servers and the Web applications that you plan to deploy on them, but also it protects your production servers from being randomized by unpredictable problems. It is best if you set up your tests in a controlled environment, such as a lab, and isolate the servers from extraneous loads. Concentrate the test servers on stressing your hardware setup and Web applications.

Testing plays a vital role in the success of your upgrade from IIS 4.0 to IIS 5.0. In your test environment, you could discover a number of types of problems that would be disastrous to encounter on your live site. These might include any number of issues that will affect your Web server's performance. You may discover that you need to add more RAM, or that the ASP application you were hoping to deploy along with your upgrade of IIS 5.0 has too many bugs to go on the Web. If you eliminate as many of these issues as possible during the testing stage, you will have a greater chance of a smooth upgrade.

One recommended course of action is to use a methodical upgrade from IIS 4.0 to IIS 5.0. This involves creating a set of tests for IIS 4.0, running them, and then performing the upgrades and running the exact same tests on IIS 5.0. Not only does this allow you to find any performance-related problems, but it also allows you to estimate the performance gains you will receive from upgrading. You can use tools like System Monitor and the Web Application Stress tool to monitor performance during tests and to generate test scenarios, respectively.

Once testing is complete, it is suggested that you set up an IIS 5.0 system. This means going live with your servers to a limited audience who will help you stress test your servers and applications in an environment more closely resembling real-world conditions than your test lab. Using your company's intranet could be an optimal environment to pilot your new deployment. During the pilot, you test your design in a controlled real-world environment in which users perform their normal business tasks using the new features. Remember to continue monitoring the performance of your servers throughout the pilot period. For details about designing your Test and Pilot deployments, see the "Deployment Planning Guide" at http://www.microsoft.com/WINDOWS2000/library/resources/reskit/dpg/default.asp.

While both testing and piloting are excellent practices, neither can completely reproduce the type of use and amount of load that your Web servers will experience. After all, testing and piloting occur in controlled environments where network latency is minimal, and the kind and amount of requests being generated are known. When your servers and applications go live, you expose them to the entire Internet and its users.

It is vital that you continue to monitor your servers after the deployment of IIS 5.0 onto the production computers is complete. As stated earlier in this appendix, this will allow you to establish baseline performance records that you can use to determine whether performance is going up or down. Don't forget to compare the baseline numbers to the new numbers any time you make a change to your production servers so that you can see what effects your change has had on performance. It is best if you only make one change at a time; otherwise, you will often not be able to tell which change produced which effect. If you make multiple changes, it is likely you won't be able to determine the effects of either. If performance does not improve as you expected, continue to analyze the data and make adjustments as indicated. Monitoring should continue on a regular basis, but tweaking performance settings will become less necessary over time.