Dual-Chord:一种更加有效的分布式哈希表

Dual-Chord:a More Effective Distribute Hash Table

在基于分布式哈希表构造的对等网中,关键字的搜索效率一直是一个非常重要的指标.Chord提出在Chord环上构建结构化的分布式哈希表.Chord协议中查找的过程是单一的顺时针方向.Dual-Chord通过对路由表的扩展,使得系统的查找策略可以根据关键字在Chord环上位置离当前节点的远近来确定查找的方向,这样大大的提高了在对等网中的查找效率.同时,Dual-Chord综合考虑了网络延时对查找的影响.在设计中也根据节点间的网络延时来优化查找的性能.实验表明,在对等网中Dual-Chord协议定义的查找算法效率比Chord定义的查找算法要高.

In the DHT based peer-to-peer network environment, the efficiency of searching keywords is an import mark. The Chord protocol raised that building a structured hash table on Chord ring. In the searching processes, the direction of search is just clockwise. By extend the router table of Chord. The Dual-Chord protocol raised in this paper can achieve the bidirectional search by the distance between the keywords and the alternate node. So, this strategy make the search path be much shorter. As the same time, the network latency is also taken in as a parameter of network performance. In the design of Dual-Chord, the network latencies are used to help the algorithm to select an optimum path. The experiment result shows than the Dual-Chord is more effective than Chord in the searching process.