Active composition of web services based on quality of service

Web services are modular, self-describing, self-contained, platform-independent software components that can be published by service providers over the Internet. Web service composition (WSC) is the task of combining a chain of connected single services together to create a more complex and value-added composite service. For those web services providing the same functionality, quality of service (QoS) has been mostly applied to represent their nonfunctional properties and differentiate them for service composition, these approaches do not guarantee finding a solution satisfying the global QoS constraints for a composition task, even if there exists one under a different workflow. In this paper, we propose and validate DoWSS, a doubly weighted algorithm for service traffic shaping. We show via simulation that DoWSS possesses several advantages: It eliminates the approximation issues, prevents starvation, and contains the rapid credit consumption issue in existing credit-based approaches.