Enhancing Web Services Performance Using Adaptive Quality of Service Management

摘要

The variation of contexts in which a Web service could be used and the resulting variation in Quality of Service (QoS) requirements motivates further research to extend Web services management platforms with automatic and adaptive management mechanisms in order to achieve differentiated service offerings and to improve quality of service in terms of availability, response time and throughput. However, most Web services platforms are based on a best-effort model, which treats all requests uniformly, without service differentiation. This paper presents WS-DiffServ, a service differentiation middleware based on adaptive scheduling of service requests that prioritizes requests depending on their associated class of service and the current degree of service level conformance. The goal of the proposed approach is to increase conformance to negotiated service levels particularly in case of overloads such that the incurred penalties for violations are minimized. The paper first explores the typical requirements of a differential QoS support for Web services. We then present the design of WS-DiffServ. The effectiveness of the proposed approach is analyzed using supply chain management scenarios.