The concept and practice of software load testing has been around for many years, but the advent and exponential growth of the Internet has created a situation that has taken the magnitude, complexity, and importance of load testing to a whole new level. In this paper we present the overview of a methodology for approaching the very challenging task of load testing Internet websites in a rigorous and systematic manner, in order to collect, realistic and reliable data about a website∆s capacity and scalability. In the first part of the paper, we introduce, define, and explain the key variables and metrics that are used to understand, analyze, and generate highly realistic load tests for Internet websites.
In the second part, we introduce and explain the concept of Website Usage Signature (WUS) and use it to describe the process for developing and validating load testing scripts and scenarios that accurately match the way a website is used and navigated by real users. In the final section, we address some of the practical problems and concerns associated with the actual execution of website load tests.
Alberto Savoia is founder and CTO of Velogic Inc., a professional services company that specializes in website load testing. In his 15-year career he has been consistently and passionately committed to improve the state of the art in software testing through the use of formal methods and automation, and has been granted several software patents, including 2 US patents in the area of test automation. Prior to Velogic, Mr. Savoia was founder and General Manager of SunTest, a business unit of Sun Microsystems that developed and marketed award-winning Java testing tools for API, GUI, and load testing.
Before SunTest, Mr. Savoia, was Director of Software Research at Sun Microsystems Laboratories where, among other projects, he started and led the ADL (Assertion Definition Language) project, a highly successful, 3-year, $4M, joint international research effort in automated test generation for object oriented systems.