一种基于云存储的CDN视频副本部署策略  

A novel video replica placement strategy for storage cloud-based CDN

作　　者：姚士佳 朱明[1] 崔昊旻 

机构地区：[1]中国科学技术大学自动化系,安徽合肥230027

出　　处：《中国科学技术大学学报》2014年第7期554-562,共9页JUSTC

基　　金：中国科学院先导专项(XDA06030900);国家科技支撑计划(2012BAH73F01)资助

摘　　要：在线视频服务无法离开CDN(content delivery network)的支持.与传统CDN相比,使用云存储节点作为CDN的节点对视频内容进行分发可以节省大量运营费用.在线视频服务的内容文件要尽量预先部署到离用户较近的边缘节点上,以保证用户的QoS(quality of service).现有的GS(greedy site)内容预部署算法在有历史记录的前提下,有着较小的货币开销,且能满足QoS需求.然而,GS算法会导致云存储节点的负载均衡情况较差.为此,提出了一种称为GUCP(greedy user core preallocation)的部署算法,该算法利用k-means算法将负载过重节点上的用户分配到负载较轻的节点以平衡负载,解决GS算法在负载均衡方面存在的不足.实验表明,GUCP算法在系统使用费用、QoS性能方面与GS算法十分接近,在负载均衡性能上远远优于GS算法.Online video service needs the support of CDN （content delivery network） which can be costly . Using cloud storage nodes to deliver video content can help solve the problem .To guarantee the users＇QoS ,CDN should pre-deploy the content files of online video service to the edge nodes w hich are close to the users . The existing GS （greedy site） placement algorithm can satisfy the QoS requirements at a relatively smaller cost when the historical log is provided .However ,the GS algorithm will result in bad load balance among cloud storage nodes .A novel replica placement algorithm named GUCP （greedy user core preallocation） was proposed to solve this problem .The algorithm assigned users on overloaded nodes to lightly-loaded ones using the k-means algorithm , in order to balance the load . The numerical experimental results show that the cost and QoS performance of GUCP are very close to those of GS ,while its performance of load balance is much better than that of GS .

关 键 词：云存储 CDN 副本部署 负载均衡 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]