由于服务是由彼此独立的提供商开发的,无法在开发阶段就预测到其潜在的所有交互可能,因此需要在实际协作时检查服务之间的兼容性,从而保障协作的正确性和一致性.提出了一种基于分布式协调模型的方法,以提高服务的可复用性和服务协作的灵活性.该方法通过失败等价(failure-equivalent)行为语义保持的投影规则,将协作流程转换为协作子流程,以实现分布式的成对兼容性检查,并提出基于适配的检查方法,检验服务是否可以通过适配机制满足兼容性的要求,同时给出了适配器自动生成的算法.适配机制的引入进一步降低了服务与协作环境的耦合关系,从而在保持服务组件自治特性的同时提高了服务协作的灵活性.
As services are developed by independent providers, it is impossible to predict all potential interactive possibility at development stage. In order to ensure the correct service collaboration, it is necessary to check the interaction compatibilities among participating services. This paper presents a top-down approach to improve the reusability of available services and the flexibility of service collaboration based on a decentralized mediation model. Through failure-equivalent projection, the collaboration process is transformed to decentralized processes, which facilitates a more efficient pair-wise compatibility cheek. A mediation-based method is proposed to check if the compatibilities can be achieved by using mediation mechanism. Algorithms of compatibility check and automatic mediator generation are also provided. This approach makes the coupling between available services and collaborative environment more looser, thus improving the flexibility of collaboration while preserving the autonomy of services.