Summary

Test scripts require a significant investment in planning and development. Good scripts exercise your web site as your users do, and allow you to accurately measure your application's performance. They also give you the basis for web site capacity planning. Conversely, bad scripts often generate inaccurate capacity data or, even worse , leave serious performance problems undetected until the web site enters production. Create scripts that test through the various layers within your application so you know which operations require the most time.

Script writing requires some planning. Write small, atomic scripts for easy insertion in a variety of scenarios. Use your knowledge of typical usage patterns to develop relevant test cases. Also, begin your testing with the most frequently visited areas of your web site, and add scripts to cover the less-traveled areas as time permits . Your scripts need lots of variation to simulate the breadth of requests the site receives and to avoid skewing the performance by using cached items. Finally, use the appropriate weighting to realistically reproduce the distribution of traffic on your web site.

Building test scripts and selecting a test tool need to be taken seriously. In the next chapter, we discuss test tool selection in detail.