Workload Generators for Web-Based Systems: Characteristics, Current Status, and Challenges

The growth and evolution of the World Wide Web (WWW) has been rapid over the last ten years and this has been caused mainly by factors such as the social Web and mobile technology. This growth, which presupposes the satisfaction of millions of users accessing Web applications with an adequate quality of service, requires continuous changes in the infrastructure to improve user experience or to handle new demands. Therefore, studies of Web-based systems aimed at comparing different hardware infrastructures, detecting system bottlenecks, provisioning hardware resources, making capacity planning tests, or software testability, are a matter of huge interest. However, the new trends in the WWW have brought new types of user demands and interactions that produce complex workload patterns. These patterns must be exhaustively studied and considered when designing helpful workload generators able to produce representative traces of the current reality. This survey is aimed at providing a useful guide for researchers of the Web, social networking, and other Internet related issues, regarding the main points and concerns about workload generation for Web-based systems. This paper reviews the predominant characteristics and attributes that define Web workloads, including the special cases of other types of Web applications (e.g., blogs, online social network platforms, and video-sharing services). It also identifies the main challenges for the next generation of Web workload generators, and explores current approaches and solutions suggested in recent works.