Research On Service Relationship-based Web Services Composition And Related Technology

With more and more applications provided in Web Services thechnology, it is critical to have a method to compose services using by available Web Service, which is dynamic and meets the user's personal needs. The object of Web Services Composition is to build the executive sequence of atomic web services, so we argue that descriptions of individual services do not capture the inter-relationships among services. The linear set of individual services without any structures can result in inefficiency in service discovery and identification. Supported by National Nature Found of "Mobile Intelligent Service Platform" and National Basic Research Priorities Program (973) of "The Framework of Authentic and Integrative Web Service", we begin with service relationship, analyze the relation ship from three views, and we research on the related critical questions referred to Web Service Composition. The main contributions are as follows:(1) Especially for information providing Web services, this paper analyses the services relationship from the view of service topic, and proposes an information service organization model - Topic Maps based Data Model for Web Service (TMDM4WS). TMDM4WS analyzes the web services relationship causing by information association, organizes the available web services by Topic Maps technology, and it presents the implementation by Top Maps based Service Organization Ontology (TMSRO) in OWL DL, which is a new type of application ontology. The model is analyzed in theory and the preliminary prototype shows that the about model can provide excellent service querying results, and it is feasible and effective in services discovery and composition.(2)This paper analyzes the services relationship form view of business logic. Business policy needs to be represented explicitly, to be understood by semantics, and to be applied automatically. This paper proposed a SWRL-based business policy model (SBPM) which does the rule reasoning based on semantics, and introduces the method that trasfers the rule to Service relationship dynamically. SBPM bridges the gap between business requirements and academic research. As a result, the 3rd part service providers can focus on the business goals to be achieved, and the composite service could be controlled by busienss logic.(3)This paper proposes an interactive and dynamic method - Service Relationship Ontology-Based Web Service Composition Method (SROCM). Based on the first two contributions, SROCM presents a method for building the Services Relationship Ontology (SRO) which reflects the services relationship from three views. When composing, SROCM mines the dynamic semantic of services to achieve the interests of users and gets recommend subsequence services using by SRO. The semi-automatically method could get an optimized service matchmaking results, adapt for variety of requirements of both customers and service providers flexibly, and ensure efficiency while composing service. The preliminary experiments show that about method can provide excellent subsequent service according to user's interests, and it is feasible and effective in dynamic service composition.(4)In interactive Web Service composition, the performance is decided by the atomic Web Service. We consider the Web Service and network elements as one system and a closed-queuing network model is proposed which has several characteristics such as finite-source, multi-class services and session-based requests. And then it is simplified to an M/G/1/K+Y/H PS queue model to just analyze the Gateway. Experiments are conducted on the real Parlay X system, and several metrics are evaluated to improve the system performance. Experimental results indicate that the queuing network model and simplified model captures the performance of gateway systems faithfully, and they can play an important role in system bottleneck identification, performance prediction and application configuration.