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

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. Making 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.