面向IaaS的云计算系统可用性评估  

Cloud Computing System Availability Evaluation for IaaS

作　　者：李阿妮[1] 张晓[1,2] 赵晓南[1] 张伯阳[1] 柳春懿 LI A-ni ZHANG Xiao ZHAO Xiao-nan ZHANG Bo-yang LIU Chun-yi(Department of Computer Science, Northwestern Polytechnieal University, Xian 710129,China State Key Laboratory of High-end Server and Storage Technology,Jinan 250101 ,China)

机构地区：[1]西北工业大学计算机学院,西安710129 [2]高性能服务器和存储技术国家重点实验室,济南250101

出　　处：《计算机科学》2016年第10期33-39,共7页Computer Science

基　　金：国家863重大项目(2013AA01A215);国家自然科学基金面上项目(61472323);西北工业大学基础研究基金(3102015JSJ0009);高效能服务器和存储技术国家重点实验室开放基金项目(2014HSSA11)资助

摘　　要：随着云计算应用范围的扩展,人们对云计算在安全性、可靠性、可用性等方面的担忧与日俱增。云计算服务商承诺提供的服务满足服务水平协议,主要包括性能和可用性。但是,因可用性的内在复杂性而缺乏定量评估手段,对于云计算系统用户而言更是如此。为此,提出面向最终用户和面向云计算服务提供商的云计算系统可用性评估方法,这两种方法都采用可用性的定义建立模型,并且采用虚拟机的启动时间代替平均故障修复时间(Mean Time To Repair,MTTR)。第一种方法的平均失效前时间(Mean Time To Failure,MTTF)采用云计算服务提供商提供的参数;第二种方法通过统计得到虚拟机的MTTF,并计算云计算系统之上的集群可用性。由于难以对后者进行实验验证,因此只对第一种方法进行验证,通过实验测量公有云和私有云提供的虚拟机的启动时间,结合云计算服务提供商提供的MTTF,计算了两种不同云平台服务的可用性,该方法方便用户快速计算可用性,为用户选择不同的云服务提供建议,并且可以判断云计算服务提供商的承诺是否达到标准以及是否可以将一些关键行业应用服务迁移至云平台。With the expansion of the cloud computing application,people are getting worried about the security, reliabili- ty and availability of cloud computing. The cloud computing system promises to provide the services that meet the servi- ce level agreements which commonly include performance and availability. However, because of the inherent complexity of the availability, the evaluation of availability lacks quantitative calculation method, especially for the cloud computing system users. To solve these issues, we proposed an end-user oriented and a cloud computing service provider oriented cloud computing system availability evaluation method. These two methods adopt the definition of the availability to build model and take the boot time of the virtual machine as mean time to repair（MTTR）. The mean time to failure （MTTF） of the first method adopts the parameter which is provided by cloud computing service providers. The virtual machine~ s MTTF of the second method is statistically obtained, meanwhile, the cluster availability of the cloud compu- ting system is counted. Because it is difficult to carry out experimental verification for the latter, therefore, we only veri- fied the first method. We measured the boot time of the virtual machine in public clouds and private clouds, and com- bined the MTTF which is provided by cloud computing service provider. Finally, we calculated the availability of two different kinds of cloud computing services. This method facilitates users to calculate the availability quickly and pro- vides recommendations for users to choose different cloud services. In addition, users can judge whether the cloud com- puting provider＇s promise reaches the standard and whether some important industry application services can migrate to the cloud platform.

关 键 词：云计算 可用性 平均失效前时间 平均故障修复时间 定量计算 

分 类 号：TP301[自动化与计算机技术—计算机系统结构]