Decentralized Orchestration with Local Centralized Orchestration for Composite Web Services

During the execution period of composite Web services, the conventional centralized orchestration (CO) tends to incur various drawbacks such as unnecessary traffic, inappropriate dependencies, etc. Decentralized orchestration is advocated to solve these drawbacks but results in some other ones if the pure decentralized orchestration (PDO) is adopted such as high cost for component Web service proxy deployment, weak execution monitoring, etc. In this paper, by deriving the concept of affinity for component service relationship modeling and employing the novel service granule facility, we propose the decentralized orchestration with local centralized orchestration (DOLCO) to cope with the problems encountered by PDO. Experiments show that DOLCO can serve as the complement or alternative of decentralized orchestration.