Design and Testing of Scalable Web-Based Systems with Performance Constraints

Modern Web sites provide multiple services that are deployed through complex infrastructures consisting of distributed components, processes and server nodes. The importance and the economic impact of consumer-oriented Web sites introduces significant requirements, mainly in terms of user perceived performance and scalability. This paper presents some methods for the design and testing of modern, dynamic Web sites and for the improvement of existing systems that must satisfy some performance constraints even in the case of unpredictable load variations. A case study describes the application of the proposed methods to a typical consumer-oriented Web site.