基于动态阈值的VOD虚拟机集群预调度算法

Dynamic Threshold-based Pre-scheduling for VOD Cluster in Virtual Environment

如何构建支持大规模并发用户的视频点播(VOD,Video-on-Demand)服务是当前的热点研究问题。虚拟机集群因具有多实例、可封装和按需资源分配等特性,将成为构建大规模VOD服务的支撑技术。但是,现有虚拟机集群调度方法还难以应对VOD服务中点播行为的随机性与虚拟机调度的滞后性。为此,我们提出一种基于动态阈值的VOD虚拟机集群预调度算法,通过预测虚拟内存资源利用率最高时刻的用户链接数,动态地更改调度阈值,完成虚拟机集群的预调度。实验验证该算法可降低VOD服务中的时延抖动,并提高系统资源利用率。

It becomes a research focus to build a large-scale concurrent user access behavior. For Video-on-Demand （VOD） service which supports its feature of multi-instance, packageable and high-performance, the virtual machine cluster will be a supporting technology to build large-scale VOD service. However, the existing virtual machine cluster scheduling method still have difficulty in dealing with the problem of random end-user behavior and hysteresis quality of virtual machine scheduling. A dynamic threshold-based pre-scheduling algorithm for VOD cluster in virtual environment was proposed. By predicting the VOD application workload when the bottleneck resource utilization ratio reaches the peal the value of scheduling threshold was dynamically modified and then the virtual machine cluster was scheduled. The experiment results indicate that the dynamicthreshold-basedper-scheduling algorithm can not only effectively reduce jitter incidence for VOD application, but also can improve the operating resource utilization ratio.