Research And Implementation Of Distributed Business Execution Mechanism With QoS Guaranteed

With the development and popularization of Internet technology, more and more Web Services available in the network, but the function of single service is too limited to meet the needs of users, so Service Composition is required to construct a new, complex, value-added business from multiple services. As a number of services from the service network can provide the same functionality, quality of service becomes an important factor for users to measure the property of services, and QoS guaranteed Service Composition has been the hotspot of current research. However, current service composition algorithms are mostly centralized, using the centralized composition engine to find the optimal business path from the service information, and most of current business execution systems are also centralized, using the centralized execution engine to execute entire business. Such methods have the shortages of centralized systems, such as bottleneck, failure of single point, and poor scalability.Against the shortages of centralized systems, the research of this paper is based on a distributed business execution platform Independently developed, which is based on service overlay network constructed with Chord network to organize service nodes, and implements functions of distributed business execution, distributed service registration and distributed service discovery.In order to guarantee the global quality of service and resolve the branch convergence problem for parallel process with the platform, this paper proposed a distributed service composition strategy. Taking into account the specific QoS attributes, the strategy contains two main steps, First, business is made available in the platform by routing forward to query service node information and deploy routing tables; then, by routing reverse, each node generates path tree or path map including current node and following nodes, and use depth-first traversal to obtain several optimal paths as a basis for the composition on the previous nodes; At last, the strategy can compose business paths with quality of service guaranteed and resolve the branch convergence problem.Finally, the distributed service composition strategy is applied in the platform, and experiments are done on the following aspects of the strategy: effectiveness, success rate of composition under different node failure and composition time. The results show that, the distributed business execution platform can provide QoS guaranteed paths to users, and the entire platform has strong scalability and robustness, without the problem of bottleneck and failure of single point.