A Study On Key Techniques Of Enterprise Application Integration Oriented Service Composition

With the development of web service technology, more and more enterprises wrap their own business application as web service to be deployed on the web, that makes the Internet evolve to be an open distributed computing environment gradually. In such an open network environment, how to achieve the cross-organizational and cross-enterprise application integration has become a research topic with broad needs in the fields of business, government, science and military. The technology of service composition which integrates the relatively simple web services into a more complex one with more powerful and complete business functions has become a trend of developing enterprise application integration.Taking the requirement of cross-organizational and cross-enterprise application integration in the open network environment as the background, the project team of the author develops an enterprise integration platform-which is based on the service composition and its key techniques. The developed enterprise integration platform has been put into practice in several companies and departments. In this paper, for the problems such as how to ensure the efficiency of the composite service, how to support the human task as well as how to analyze and diagnose the exceptions of the composite service to ensure its reliability faced in the practical project implementation process of the platform, several researches have been done in the facets of mechanism, algorithm and model theory, the corresponding solutions are given and the main works include:(1) For the problem of how to ensure the execution efficiency of the composite service, the hybrid composite service execution mechanism which is based on the centralized control-flow and data-flow schema as well as the centralized control-flow and decentralized data-flow schema is researched. This mechanism can ensure the efficiency of the composite service execution by the dynamic selection and switching between the execution schemas. Firstly, the hierarchical structure of the mechanism is given. Then, the hybrid execution oriented interaction protocol between the composite service execution engine and the service agent is established which can implement the flexibility switching between different execution schema. Next, the execution environment feature model is formed and based on this model the two-stage selection algorithm for execution schema is proposed, which includes the pre-selection and dynamic selection algorithms to achieve the self-adaptive selection of the execution schema in the context of different network states and business. Finally, the experiments verify the effectiveness of the proposed hybrid execution mechanism.(2) For the problem of human task support and its effectively scheduling problem in the execution of the composite service, the human task execution mechanism and its scheduling algorithm are researched. Firstly, the architecture of human task oriented human service container is given which can implement the flexible invocation of the human service resource from the composite service execution engine, and ensure the support of the human task in the service composition environment. Then, the performance evaluation model of the human service resource is formed which can be used to reflect the actual effect of the human service resource. Next, the objective function of the human task scheduling problem is presented and the two-stage human task scheduling algorithm to solve this problem is proposed which includes initial human task scheduling and delegation authority based re-scheduling algorithms. Finally, the experiments verify the effectiveness of the proposed two-stage human task scheduling algorithm.(3) For the problem of reliable execution oriented exception analysis and diagnosis of composite service, the exception diagnosis algorithm for composite service is researched. Firstly, the error propagation relation between services in the composite service is analyzed, and the framework of the exception diagnosis approach which is a combination of global and local diagnosis is presented. Then, for the global diagnosis of the composite service, the method for computing the error propagation degree is given which reflects the uncertain cause and effect relation between the service and the exception. Next, based on the computation of error propagation degree, the exception diagnosis model which is based on the error dependent matrix is formed, by diagnosis reasoning based on fuzzy logic, the most likely error source can be obtained. Finally, the experiments show the feasibility of the exception diagnosis algorithm.(4) In order to verify the practical effect of the proposed mechanism, model theory, the core algorithms and other key techniques, based on the established SOA based enterprise application integration platform, with the combination of the practical application cases, the specific implementations of the researched key techniques are pressed and their practical effect is evaluated. The practical results show that the hybrid execution mechanism of the composite service, human task execution mechanism and its scheduling algorithm as well as the exceptional diagnosis algorithm of the composite service can solve the problems of how to ensure the efficiency of the composite service, how to support the human task as well as how to analyze and diagnose the exceptions of the composite service to ensure its reliability faced in the practical process.