基于信任的云服务系统多目标任务分配模型

Trust-Based Multi-Objectives Task Assignment Model in Cloud Service System

云计算等新兴信息技术推动了服务产业的转型升级,然而云服务在带来远程服务和按需使用等便捷的同时,也拓展了原有信息安全的边界,引发了新的安全问题.基于信任机制的安全管理给云安全问题提供了全新的思路.在云服务中引入信任机制,用以衡量多云环境下不同云服务资源的可信程度,建立了基于信任的业务流程驱动云服务选择和任务分配模型,梳理总结了6种典型的任务结构关于时间、成本和信任的函数关系式,在高效率和低成本基础上保障安全可信性;提出了一种改进SPGA2算法,引入了局部搜索策略,以提高混合云环境下可信的多目标任务分配问题解空间的搜索效率;并最终通过仿真实验,验证了模型可用性和算法优越性.

Cloud computing with other emerging information technologies promotes the transformation and upgrading of the service industry.The new mode of cloud service brings the convenience and agility by the remote service and on-demand use.Meanwhile,it also expands the existing information security boundary,trigging new security problems.Trust mechanism provides a good solution for the security problem of cloud service.This paper builds a service-oriented architecture of task assigning system in the cloud environment.It introduces the trust mechanism into cloud services by measuring the trust requirement of tasks and the trust degree of service resources.Considering the execution time,cost and trust as optimization objectives,we propose a business process driven multi-objective task assignment model in the cloud service system.Some typical structures：sequence,parallel,parallel-AND,parallel-OR,parallel-XOR,simple loop and combined loop are introduced to represent the functions of business process structures.The three objectives are set to keep security and trust of the system based on high efficiency and low cost.An improved strength Pareto genetic algorithm 2（SPGA2）with the local search strategy is proposed to improve the search efficiency of solution space in multi-objective task assignment problem.Finally,simulation experiments verify the availability of the model and the superiority of the algorithm.