Composite Services Quality Credibility Evaluation In Cloud Computing Environment

At present,with the development of computer technology,the application of cloud computing is more and more widely.Because cloud computing has the characteristics of unlimited resources,the providers of cloud computing services are increasing and the types of services are becoming more and more perfect.A single service provider is generally concerned about a particular area of business,because of the limited functionality of a service,it can only meet a certain application.At present,the service needs to be multi-functional and have complex features,make use of the existing service the cloud computing environment.A number of existing single service according to the logic relation between the combination of new integrated services,can accelerate the speed and reduce the system development cost and meet the functional requirements of complex application system construction.The core of service composition in cloud computing environment is how to correctly evaluate the trust degree of composite services.Considering the safety problem of service composition of current trust research,basically to services provided by the QoS selection sub service based,less consider the difference between actual combination operation sub service,and rarely involve the service combination,so can not adapt to the cloud computing environment.In this paper,we design a model of trust degree of service composition based on the characteristics of multi-level services in cloud computing environment.Firstly,the trust evaluation mechanism is established,and the trust degree of the service quality is evaluated from two aspects of static and dynamic.Analysis of the QoS and the history of the evaluation records,and trust evaluation criteria to match,determine the static evaluation of its trust.The dynamic evaluation of the trust degree of sub service is obtained by processing the historical data of the existing service composition.Secondly,the trust evaluation mechanism of the composite service is established and the evaluation algorithm of the trust degree is designed.The algorithm is based on the trust degree of sub services.Taking into account the weight of service,service composition and constraint algorithm,we can ensure that the trust degree of the composite service has a high degree of credibility and improve the satisfaction of users.In this paper,the overall evaluation model is simulated,and the simulation results verify the feasibility of the algorithm and model.