【作者】 胡睿；

【导师】 苏森；

【作者基本信息】 北京邮电大学 ， 计算机科学与技术， 2013， 硕士

【摘要】 随着互联网以及Web2.0的迅速发展,应用所处理的用户请求日益增长,给服务提供商的本地数据中心造成了巨大的压力。服务提供商为了应对日益增长的用户请求,需要不断地加大本地数据中心的硬件投入。然而,本地数据中心存在硬件购置的成本高、维护困难和资源利用率低等缺点。在这种情况下,云计算作为一种新兴的计算模式应运而生,并有高可靠性、高可扩展性以及按需收费等优点。越来越多的服务提供商为了降低成本和保证服务质量,选择租用基础架构(Infrastructure-as-a-Service, IaaS)提供商的计算资源构建资源环境。然而,IaaS提供商提供不同处理能力和不同计价模式的虚拟机,并按租赁时长进行收费。不同的虚拟机租赁方案会导致完全不同的租赁费用开销,这是服务提供商必须考虑的问题。另外,并行应用请求称为服务提供商所处理应用请求的重要组成部分,这类应用一般通过工作流进行抽象。因此,在处理工作流这类应用请求时,服务提供商面临的主要问题是：如何针对工作流这类应用的特点设计虚拟机调度策略,在保证服务等级协定(Service Level Agreement,SLA)的前提下,达到降低虚拟机的租赁费用开销的目标。本文针对此问题,建立云计算环境下的虚拟机资源调度模型,为服务提供商设计了一种并行应用请求调度算法。首先,本文提出了单工作流虚拟机调度算法,并在此基础上提出多工作流虚拟机资源调度算法。其次,我们基于CloudSim仿真平台开发虚拟机调度策略模块,用于对论文提出的算法进行仿真和性能评估。最后,基于真实的并行应用请求对算法进行测试,通过对测试结果的分析,验证了我们的算法能够在满足服务等级协定的前提下,有效降低租用虚拟机的费用开销。更多还原

【Abstract】 As the development of Internet and Web2.0, the amount of requests that the applications face has increased dramatically and put huge pressure on the local datacenters of service providers. Therefore, service providers need to increase the investment in hardware of their datacenters in order to meet the ever-increasing amount of requests. However, local datacenters have some disadvantages including high cost in hardware investment, difficulties in operation and low resource utilization etc. Under these circumstances, cloud computing emerged as a revolutionary computing paradigm. Cloud computing has some advantages including high reliability, high scalability and pay-as-you-go pricing model etc.In order to reduce the cost and guarantee the quality of their services, more and more of service providers choose to build computing environment based on the infrastructures provided by IaaS (Infrastructure-as-a-Service) providers. VMs (Virtual Machine) that IaaS providers provide differ in computing capacity and pricing model. Different strategies to rent VMs will result in different rental cost, which has become an important issue for service providers. Additionally, requests of parallel applications, which can be abstracted as workflows, are the integral part of requests that service providers deal with. While dealing with this kind of requests, service providers’problem is how to make VM scheduling strategy according to the application’s characteristics in order to achieve the goal of reducing rental cost and guarantee SLA (Service Level Agreement) at the same time.To solve this problem,this paper brings forward theVM scheduling model in cloud computing environment and designs an algorithm for service providers to schedule parallel requests. First, this paper designs single workflow scheduling algorithm and based on which designs multiple workflows scheduling algorithm. Second, we design and implement the VM scheduling module based on CloudSim, and use it to evaluate the performace of the algorithm. Finally, we use real-world parallel requests to test the algorithm and the results demonstrate that our algorithm can effectively reduce the rental cost of VMs as well as ensure the SLA of the services.更多还原