Agent-based Dis-graph Planning Algorithm for Web Service Composition

In agent-based planning for service composition, a single agent may not have access to all services required to fulfill a given goal. Cooperation among multiple agents, each of whom has a limited set of services, can increase the chance of generating a valid/effective composition. However, agents may be reluctant to reveal their services to other agents during cooperation due to the concerns to privacy, security, and difficulty of a heavy communication overhead. In this paper we present a distributed algorithm that allows agents to cooperate and form a composition in such a situation. This algorithm can be viewed as a distributed extension of the reputed centralized planning paradigm, i.e. graph planning + CSP. We adapt classical planning graph to distributed planning graph, represent the graph in distributed CSP (DisCSP) instead of CSP, and solve the DisCSP with distributed search algorithm. All agents have equal authority and no centralized coordinator is required in the whole process.