对等网络系统面临的最大的问题就是负载均衡.针对P2P网络中负载均衡的问题,提出了两种基于动态副本策略的负载均衡技术:周期性副本策略和基于需求的副本策略.在周期性副本策略里,每个超级节点周期性地把文件的副本发送给请求该文件频率最高的远程超级节点.在基于需求的副本策略里,当一个超级节点发现其对某个文件的访问频率过高时,就向拥有该文件的超级节点发送文件请求,以获得该文件副本.本文分析了这两种技术的平均访问代价和副本负载代价.一系列的模拟实验证实了这两种技术的可行性及其带来的好处.
Load balancing is a critical issue for the efficient operation of peer-to-peer (P2P). First,this paper gives two load balancing techniques which are based upon dynamic replication policy:Periodic Replication Policy (PRP) and Demand-based Replication Policy (DRP). In the first one,each super peer periodically sends a file's replica to remote super peer which has the most frequency of accessing the file. In the second one,when a super peer finds a file has been requested at a high frequency through itself,it will request the super peer who has the file to send it a replica. Besides ,this paper analyzes the average access cost and the replication overhead cost of these two techniques respectively. Finally,a set of experiments prove the feasibility and benefit of the proposed techniques.