Choosing the User Scenarios to Load Test
The first step in building a load test is to choose the scenarios to test – this is frequently harder than one might guess. When we ask customers which scenarios we should test first, a common answer is “test them all”. While this might yield the most accurate results, it is rarely practical for the allotted budget and schedule. There is great value in getting load test results sooner rather than later – so we recommend testing as early as possible and taking an iterative approach.
Start with the most common operations that users will perform on the site – typically the two to five most common activities. For many sites, this will get you close to satisfying our 5/95 rule – test the 5% of the scenarios which account for 95% of the traffic. Run your first test with these.
Meanwhile, continue identifying the key pages and navigation patterns that users will follow on the site. Add those to the test suite and continue to refine the mix as development and testing progress.
Do you have an extensive functional test suite? Have you been encouraged to use that as the basis for your load test? Next week I’ll explain why this is a bad idea.
Chris Merrill, Chief Engineer
When his dad brought home a Commodore PET computer, Chris was drawn into computers. 7 years later, after finishing his degree in Computer and Electrical Engineering at Purdue University, he found himself writing software for industrial control systems. His first foray into testing software resulted in an innovative control system for testing lubricants in automotive engines. The Internet grabbed his attention and he became one of the first Sun Certified Java Developers. His focus then locked on performance testing of websites. As Chief Engineer for Web Performance since 2001, Chris now spends his time turning real-world testing challenges into new features for the Load Tester product.