A Service Workflow Composition Framework On P2P Architecture

Service composition, the construction of complex composite services from simple services on the Internet according to certain business process logics, is the key to support more powerful and more complete business functions. By dynamically composing existing services, we make it unnecessary to write complex individual services, and easy to adapt to the flexible and dynamic environment of e-commerce. This paper proposes a complete and well-structured framework for service composition. The framework,"service workflow composition framework on P2P architecture", is based on workflow technology and P2P network principle. According to layers of functions of service composition, the framework divides the whole process of service composition into eight phases: group creation and model distribution, service publication and searching, service interoperation, service call, monitoring, error addressing, composition optimization, each phase with corresponding interfaces and algorithms. A prototype is developed as a reference implementation, the details of which are discussed, and an example of which is given to support the framework. As conclusion, both advantages and deficiency of the framework are discussed, and future effort direction is proposed.The main innovations of the paper are as follows:1. P2P principle is imported to service composition, which means for services providers to initiatively claim their activities rather than to be assigned. Consequently, autonomy of service providers is provided;2. Basic rules of workflow composition are followed, but full-defined workflow model is replaced with core business logics while the details of which are transferred to participating nodes, which promotes flexibility and reusability of the model;3. Every related aspects of service composition are involved, each with corresponding solution and detailed algorithms.