Research On The Evaluation Method Of Cloud Service Availability Based On Modified Vicsek Model

Cloud computing with prominent compute ability,superior performance,low cost and high availability has affected people's life.Service availability is an important property for evaluating cloud system that can reflect the current service state of cloud system.Service availability has been a focused problem which can directly affect the performance of cloud system and the experience of users.The existing models for service availability evaluation are complex on building,which are unsuitability for the complex cloud system.In addition,the methods of service availability evaluation are with single index and high complexity.However,the Vicsek model in swarm intelligence and emergence computation provides a significant solution for the study of complex systems.The Vicsek model and its modified models with low complexity and good convergence can provide theoretical foundation for service availability evaluation of cloud.Therefore,the paper focused on the cloud service availability evaluation based on modified Vicsek model.Firstly,on the issue of the existing models for service availability evaluation are complex on building,the paper proposed an ID-Vicsek model based on individual differences.The model introduced volume and physical power on the basis of WAR-Vicsek model,which is fit the reality and improved the convergence speed of the system.What's more,the paper applied the model in cloud service availability evaluation,and verified the correctness of the model by experiment.Secondly,in view of the problems of single index and high complexity of existing methods,the paper proposed an evaluation method of cloud service availability based on ID-Vicsek model.The method combined the emergence factors and metrics of the Vicsek model to evaluate cloud service availability from connectivity,Information on liquidity,diversity,Inhibition of deficiency and Good boundary of individual layer and group layer.On the basis of the experimental results of five respects,the paper combined Interval Valued Intuitionistic Fuzzy Sets gave a comprehensive evaluation for service availability evaluation.Finally,in view of the problems of imbalance service capability and nodes failure in the process of tasks execution,the paper proposed a mechanism on service capacity equilibrium and fault-tolerant based on ID-Vicsek model.The paper took use of the feature of mutual collaboration in ID-Vicsek model implement the balance of the cloud system on service capability by constantly adjusting the capability of nodes.Through the discovery of fault nodes and the tasks migration of fault nodes,the paper realized the fault tolerance of the system,which ensured cloud system continue to efficiently provide services.