Search and replication in unstructured peer-to-peer networks：（在非结构化对等网络有哪些信誉好的足球投注网站和复制）.pdfVIP

Search and Replication in Unstructured Peer-to-Peer Networks Qin Lv Pei Cao Edith Cohen Kai Li Scott Shenker Abstract Decentralized and unstructured peer-to-peer networks such as Gnutella are attractive for certain applications because they require no centralized directories and no prec ise control over network topologies and data place- ment. However, the flooding-based query algorithm used in Gnutella does not scale; each individual query gener- ates a large amount of traffic and, as it grows, the system quickly becomes overwhelmed with the query-induced load. This paper explores, through simulation, various alternatives to gnutella’s query algorithm, data replication method, and network topology. We propose a query algorithm based on multiple random walks that resolves queries almost as quickly as gnutella’s flooding method while reducing the network traffic by two orders of mag- nitude in many cases. We also present a distributed replication strategy that yields close-to-optimal performance. Finally, we find that among the various network topologies we consider, uniform random graphs yield the best performance. 1 Introduction The computer science community has become accustomed to the Internet’s continuing rapid growth, but even to such jaded observers the explosive increase in Peer-to-Peer (P2P) network usage has been astounding. Within a few months of Napster’s [12] introduction in 1999 the system had spread widely, and recent measurement data suggests that P2P applications are having a very significant and rapidly growing impact on Internet traffic [11, 15]. Therefore, it is important to study the performance and scalability of these P2P networks. Currently, there are several different architectures for P 2P networks: Centrali