| Service Oriented Architecture (SOA) is an emerging software engineering paradigm for developing distributed applications in the Internet era. In this paradigm, web services from different organizations are composed to realize business goals. To safeguard application consistency in such an environment, atomicity is a desirable property for a service composition, in the sense that the service composition could either terminate successfully or abort without any side effects. However, conventional database transactions are inapplicable in such an environment due to the long-running, distributed, autonomous and heterogeneous nature of web services. Instead, exception handling, a weak consistency approach, is often adopted to resolve application inconsistency based on the concept of atomicity sphere, a structured criterion for the atomicity property of service compositions.;In this thesis, we propose a process algebraic framework to study the atomicity property in a service composition using the exception handling approach. We discuss the following three research issues:;(1) The global analysis of atomicity sphere for a service composition. In a service composition, service providers usually provide only abstract public views of their services to service consumers. These public views expose only partial information of their services. Therefore, it is difficult to analyze the atomicity sphere of a service composition using existing work because full comprehensive information about the provided services is needed. To address this issue, we propose an approach to publishing the atomicity information of services in their public views. Service consumers could then use these public views to check the atomicity sphere in a service composition instead of using the services. (2) The local analysis of atomicity sphere in a service composition. In some situations, besides the details of their services, organizations may also not be willing to share information about their collaborators with the other collaborators in a service composition due to privacy concerns or business reasons. To check the atomicity sphere of a service composition in such scenarios, the global analysis approach is incompetent. To address this issue, we propose an alternative way to check the atomicity sphere of a service composition using a local analysis approach. (3) The detection and resolution of atomicity violations caused by implicit interactions in a service composition. Concurrent execution of services may lead to implicit interactions between services (i.e., resource sharing). Such implicit interactions may also cause atomicity violations at runtime even if a service composition satisfies the atomicity sphere. To address this issue, we propose an approach to identify only afflicted implicit interactions in a service composition, and suppress their threats to the atomicity property with extra behavior constraints.;We evaluate the framework of our proposal based on examples modeled after a couple of real life applications and the associated experimental results. |
