基于主动网络的内容分发网络研究

针对内容分发网络(CDN)中复制服务器的动态部署要求,基于主动网络技术设计了一种主动内容分发网络模型(ACDN).将主动节点部署于客户节点与Web服务器之间,并通过插件来提供主动节点的动态可编程能力,从而使网络能根据Web服务器、网络的运行状态或用户自定义的规则,动态、快速地部署复制服务器.结合遗传算法的单亲交叉算子和单亲变异算子,提出了复制服务器的位置优化算法.按请求频度确定兴趣度,以此保证复制服务器与Web服务器的内容一致性.仿真结果表明,ACDN能满足实际Web应用的响应时间的要求,同时为ACDN所设计的3种算法不仅能满足内容分发的性能要求,还能应用于传统的CDN网络.

Research of Content Distribution Network Based on Active Network

In order to deploy replica servers in CDN (content distribution network) dynamically,a novel active network based content distribution network(ACDN) was proposed,in which the active nodes are deployed between client nodes and Web servers and it provides active nodes with dynamic programmable ability by using plug-in technique so as to make network dynamically and rapidly deploy replica servers according to Web servers,network operation conditions or rules defined by users.Combining with the single parent mutation and crossover operator of genetic algorithm,a replica server placement optimization algorithm was provided.In addition,the interest measure is determined by the request frequency to maintain the content consistency between replica and web servers.Simulation results show that ACDN architecture can satisfy the requirement for time response in Web applications;and the three algorithms designed for ACDN can not only meet the performance requirements for the content distribution,but also be applied to traditional CDN.