A CPNets-based design and analysis framework for service oriented distributed systems

by 1973- Yi, Xiaochuan

Currently, more and more distributed systems are built based on the service oriented architecture (SOA), which can be implemented using Web service technologies. The benefits of SOA include better interoperability, scalability, maintainability and reuse. Service composition techniques allow creating new services by integrating existing services programmatically. They are instrumental in realizing the full potential of SOA. A typical service is often stateful: it offers multiple operations, and invoking these operations must be properly choreographed to achieve the desired result. The choreography rules can be captured and specified by a behavioral interface, also called service conversation protocol. A conversation protocol is important for a stateful service to be utilized properly. Incorporation of stateful services into a service composition poses interesting challenges, such as how to extend the current service description scheme to allow specification of conversation protocols, and how to utilize the service description correctly and efficiently. In this dissertation, we present a design and analysis framework for service oriented distributed systems. The cornerstone of the framework is a unified service specification model based on Colored Petri nets. The service specification model is suitable for both service compositions and conversation protocols, and thus it supports incorporating partners exhibiting complex protocols. It also enables formal analysis of compositions: (1) verification of the correctness; (2) automatic derivation of the conversation protocol for the newly-created composite service. The framework consists of a modeling and analysis toolkit supporting the composition model, a translator between one of the standard composition languages and the model, a novel technique to derive conversation protocol automatically from composition, and a visual composition designer that integrates design and analysis components. The framework supports service composition involving partner services with complex conversation protocols.