Research Of The Adaptive Maintenance Method Based On The Creditability Of Composite Services

As the web services are in the dynamic network environment, so they are not absolutely identified, Given the impact of network's openness, platform's heterogeneity, communication asynchronous and component's autonomy, it's very easy to occur service failure problem. When some atom service failure in a composite services, it needs perceive the failed service timely and look for new service to replace it, thus ensuring the execution of composite services. This requires to selecting a substitute service that won't have the failure problem, and a service whether prone to failure can reflect by the service creditability (Including reliability/credibility and executing efficiency and other related Qos attributes). In order to choose a service that not prone to failure in the process of composition services maintenance to maintain the composition services can execute and have long-term effectiveness. This paper will do research on dynamic adaptive maintenance of the composite services maintenance based on the service creditability. The main work is as below:In order to realize the adaptive maintenance of composite services based on service creditability. The paper defines clearly the service creditability that it is measure show the degree the Web service prone to failure at first. As simple service reliability or credibility cannot complete measure and describe the failure tendency, so the paper adopts service reliability, credibility and processing efficiency together to describe service creditability and calculate creditability using the approach of the superposition of the above uncertain factor to get the objective service creditability value, and provide proof for choosing replacement service. Also, it can avoid service"failed again"phenomena in the process of replacement.Next, this paper designs a service creditability adaptive maintenance structure based on feedback control idea and service creditability,to realize service monitor, predict and found function, and provide requisite Web service message for the maintenance of the composite service,and support the dynamic maintenance of composite services. After that, take the dynamic maintenance of composite services based on service creditability as a MDP. Under the MDP construct, we design the service replacement algorithm and adaptive maintenance algorithm, to realize the feedback controller's function, and finally realize the maintenance of composite services. The algorithm can effective lower the service response time and the system maintenance frequency.Finally, through the simulation experiments, proved the feasibility and effectiveness of the method in this paper.