一种面向动态异构网络的容错非对称DHT方法

A Fault-Tolerant Asymmetric DHT Method Towards Dynamic and Heterogeneous Network

设计具有更优的“度-直径”折衷关系,并能更好地适应动态、异构的Internet环境的DHT方法是结构化P2P技术研究的重点.提出一种容错、非对称的DHT方法:A-DHT.A-DHT根据接入延迟、带宽和用户行为把节点分成胖节点和瘦节点两类,并以Hyper-de Bruijn图为基础构建非对称的网络拓扑.A-DHT充分利用胖节点的消息转发能力实现了更优的、“平均度-直径”折中.同时,A-DHT又利用瘦节的冗余边得到了比各种基于字母表的DHT方法更好的容错性.介绍了A-DHT的静态拓扑结构、路由算法以及基于A-DHT构建P2P网络的若干算法.理论分析和实验证明,A-DHT在低网络负载条件下能够有效降低路径长度和延迟,在高网络负载条件下能够有效避免胖节点的过载,同时具有较好的容错特性.

Designing DHT （distributed Hash tables） method with optimized ＂degree-diameter＂ tradeoff and fitting dynamic heterogeneous Internet better is focus of structured P2P. A novel DHT method called A- DHT is presented. Nodes of A-DHT network have asymmetric degrees, which mean powerful nodes have larger degree for their higher access bandwidth, lower access delay and more stable user behavior. A-DHT builds its asymmetric topology based on hyper-deBruijn graph. Mak!ng use of power of fat nodes, A-DHT achieves better average degree-diameter tradeoff with controllable congestion. A-DHT also gets better fault tolerance performance than DHT methods based on alphabets by using edges of lean nodes. Static topology, routing algorithm of A-DHT and P2P network building method based on A-DHT are described. Theoretical analysis and simulation results indicate that A-DHT can reduce path length and latency at low network load, avoid overload of fat node at high network load, and achieve better fault tolerance at both two situations.