Backend Activity Profile

Backend Activity Profile

A backend activity profile is used to identify user activity and performance bottlenecks at the database tier of an existing Web application. This information can be useful to ensure your performance test is accurate.

Identifying a Web Application s User Activity

Existing databases contain concrete information concerning what your users are doing with your Web application. Examples of this type of information for a typical e-commerce application include how many baskets are being created, how many orders are processed, how many logins occur, how many searches are taking place, and so on. This information can be gathered using simple queries to extract the data from your existing database. This data can assist you in creating user scenarios, user scenarios ratios, or other marketing information that can help you make decisions from the business side. For example, you can compare the number of baskets created to the number of checkouts to find the abandoned basket rate. This information can be important to designing your stress test to execute in the correct ratio. If you find that 50 percent of the baskets created turn into actual orders processed, you can mimic this ratio when executing your performance test.

Identifying a Web Application s Backend Performance Bottlenecks

If you are performance testing an existing Web application you can identify current performance bottlenecks by interrogating the database server for queries that take a long time to process, cause deadlocks, and result in high server resource utilization. This data collection process occurs during the planning phase of the performance testing methodology, and involves capturing SQL trace data using SQL Profiler, and Performance Monitor logs that are comprised of Windows and SQL Server objects in a typical Web application. In other words, the timeframe for the captured SQL trace should be when application performance goes from acceptable to poor performance. The captured information will give you a clearer picture of where the bottleneck is occurring. Chapter 8 walks you through the process of determining the source of the SQL performance issue. These possible causes include: blocking, locks, deadlocks, problematic queries, or stored procedures with long execution times.