关键词: 无结构P2P,覆盖网络，系统吞吐量，搜索成功率，可用带宽

Abstract: The intrinsic value of P2P system is to improve the utility ratio of system resources and the system throughput,as well as to satisfy more data requests. In many unstructured P2P systems,the peers with high popularity weight in the overlay arc assigned with more connections, so as to receive more messages and hit more requests and finally to improve the search success rate. Due to the lack consideration of bandwidth, the peers with high weight are apt to be overloaded and the available services decrease. Therefore, the high success rate alone doesn't mean the high throughput and service availability. An optimization solution of overlay network was proposed in this paper to improve the throughput and the number of access customers, in which the connections are adaptively adjusted according to the available bandwidth and the popularity weight. Our simulations show that our method can improve the system throughput as high as 22% with low cost.

Key words: Unstructured P2P, Overlay network, Throughput, Success rate, Available bandwidth