Using Dynamic Asynchronous Aggregate Search for Quality Guarantees of Multiple Web Services Compositions

With the increasing impact and popularity of Web service technologies in today’s World Wide Web, composition of Web services has received much interest to support enterprise-to-enterprise application integrations. As for service providers and their partners, the Quality of service (QoS) offered by a composite Web service is important. The QoS guarantee for composite services has been investigated in a number of works. However, those works consider only an individual composition or take the viewpoint of a single provider. In this paper, we focus on the problem of QoS guarantees for multiple inter-related compositions and consider the global viewpoints of all providers engaged in the compositions. The contributions of this paper are two folds. We first formalize the problem of QoS guarantees for multi-compositions and show that it can be modelled as a Distributed Constraint Satisfaction Problem (DisCSP). We also take into account the dynamic nature of the Web service environment of which compositions may be formed or dissolved any time. Secondly, we present a dynamic DisCSP algorithm to solve the problem and discuss our initial experiment to show the feasibility of our approach for multiple Web service compositions with QoS guarantees.