Research Of Dynamic Replication Access-load-balancing Strategy On Heterogenerity Structured P2P Network

The peer-to-peer network (P2P) broke the traditional client/server mode. In P2P network, all nodes are in the equal state, which make each node can share files and transmit information freely. Due to its character of freedom, equal and inter-connect, people pay more attention to it. Structured P2P networks suppose all the files sharing the equal accessing frequency, but in real situation, all the people's demands to these files are different. In some emergency condition, the web will be flooded by people's request which makes it become the "hotspot". If the web isn't able to deal with these too hot accesses, it may be crashed. People will lose the confidence to P2P and turn to other choice because of the frequently packets-dropping. The heterogeneity of system also causes the imbalance of node's load. The node's character determines its ability to handle the access. In one word, how to make full use of the heterogeneity of system, deal with the imbalance of load, and eliminate the hotspot is one of the most important problems in the P2P network.Plenty of scholars home and abroad did a lot research on this problem, and some made good results. The popular methods are replication strategy and virtual node strategy. People prefer replication strategy. This paper first compares common load-balancing methods, then, according to the shortage, it put forward a dynamic replication strategy (DRS) based on the heterogeneous structured P2P networks. DRS could resolve the load-imbalance problem, it also take full advantage of the heterogeneity. Besides, DRS decides the number of replicas according to the node's utility and the frequency of the accessing. DRS also proposes the periodically replication managing strategy which aimed to reducing the cost of maintaining the coherence of all the replicas.In order to analyze the performance of DRS, this paper utilizes p2psim to simulate the strategy on Chord. The results show that it could balance the load to a great extent, and the number of dropping packets is also reduced. The utility of node is balanced as well.