大规模分布式VoD副本建立策略研究

The Research on Replication Strategy in Large-Scale Distributed VOD

提出了一种基于随机图搜索的副本建立策略,研究了服务获取跳转数和副本复制数对系统流量最小化的影响.发现在网络规模足够大的时候,VoD副本数和点播率服从平方根复制规律,能最大化节约系统的带宽资源.其他情况下,副本数和点播率服从线性比例复制能取得理想的结果.模拟实验和分析证明:该项研究能有效提高分布式网络中资源搜索的命中率,降低整个网络的开销,使网络中的各个节点达到负载平衡.

A logarithmic relation between the hop distance to minimization of network bandwidth used and the number of replicas is established, when the search network has a random graph topology. For sufficiently large topology, the bandwidth is minimized when the number of replicas is square-root with respect to the file request rate. Otherwise, proportional distribution is the optimal strategy. It can increase the hit rate in the resource searching efficiently in distributed network, decrease the cost of the whole network, and balance the load of every node in the network through simulation experiments and the analysis of its data.