VoD集群中基于Zipf定律的负载均衡算法  

Algorithm for load balance in VoD clustering based on Zipf's Law

作　　者：李旸[1] 吴新亚[1] 

机构地区：[1]上海立信会计学院网络信息中心,上海201620

出　　处：《计算机工程与设计》2009年第12期2945-2947,共3页Computer Engineering and Design

摘　　要：VoD服务器集群负载均衡策略主要涉及文件备份与分发两方面。现有大部分算法只是孤立地考虑其中一个方面,针对这种不足,提出一种负载均衡优化模型,综合考虑了VoD系统文件的备份与分发。提出了基于Zipf-like分布定律的备份算法和最小负载优先分发算法,增大了点播文件的备份率和减小了集群负载不均衡度。利用VoD文件点播率服从Zipf-like分布的特点,将不同文件按照不同优先级分组,降低了算法执行的复杂度。最后仿真实验结果表明了其正确性。Replication and placement problem are two aspects concerned with VoD cluster system, while most of the algorithms only consider one of them. To resolve this problem, we formulate it as a combinatorial optimization problem with objectives of maximizing the number ofreplicas of each video and balancing the workload of the servers. An optimal replication algorithm-the Zipf-like distributed based replication and a placement algorithm-the smallest load first placement are presented. To reduce the complexity of the replication algorithm, an efficient algorithm that utilizes the Zipf-like video popularity distributions is presented to classify the popularities of the videos into intervals. A comprehensive performance evaluation of the algorithms demonstrates their effectiveness.

关 键 词：视频点播 集群 负载均衡 算法 Zipf定律 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]