Abstract: Dynamic consolidation of Virtual Machine (VM) is a promising solution to address the energy inefficiency of data centers. This paper focused on VM placement and its optimization. First, in order to improve the energy efficiency, a CPU utilization-based best fit decreasing algorithm was presented to complete the VM placement. However, due to the variability of workloads experienced by applications, the VM placement should be optimized continuously in an online manner. Therefore, a threshold-based active VM migration mechanism was proposed to solve the dynamic optimization. Extensive simulation results show the proposed algorithms can significantly reduce the energy consumption and the number of VM migrations, while keeping the metrics of Performance Degradation due to Migration (PDM) and Overload Time per Active Server (OTAS) in low level.

Key words: data center, dynamic placement, energy optimization, active migration

摘要： 虚拟机动态配置是解决数据中心能耗低效的有效方法。针对动态配置过程中的虚拟机部署及优化问题展开研究，提出一种新的面向系统能耗的虚拟机部署算法以及基于主动迁移的优化策略。为了降低系统能耗，新算法采用基于服务器利用率的最佳适配降序算法求解虚拟机部署方案；同时为了适应应用负载的动态变化，新算法启动主动迁移策略对部署方案进行优化，即通过启发式算法在当前部署的基础上搜索使系统能耗更低的优化方案，并根据新部署对虚拟机执行主动迁移。考虑到迁移会导致应用服务质量降级和额外能耗，新算法通过在优化策略中设置基于服务器利用率的启动门限，对虚拟机主动迁移频率进行控制。仿真实验表明，所提算法在系统能耗、虚拟机迁移频率、服务器状态切换频率以及服务质量等多项性能指标上均有显著提高

关键词: 数据中心, 动态部署, 能耗优化, 主动迁移