针对网格集中式的资源发现方法存在单点失效、负载均衡差等问题,提出利用P2P技术进行网格资源发现方法.该方法通过改进Chord协议的后继节点函数和finger表,提出Echord(Enhanced Chord)协议,结合Echord协议特点,将网格中的虚拟组织构建成环状拓扑结构.网格资源被描述成基于XML的RDF形式,并按照一定的资源部署算法被均衡地发布在网格节点上.给出了如何应用Echord协议进行网格资源发现的算法.理论分析和仿真实验结果表明,相比于基于Chord的网格资源发现方法,该方法能改善系统的平均查找长度、消息传播性能、资源随机查找成功率.
Considering the failure of key node and poor load balance in the process of traditional grid resource discovery,this paper proposes an approach to the grid resource discovery by P2P technology.We presented an enhanced chord(Echord) protocol by modifying the chord's succeed function and finger table so as to improve the discovery efficiency of DHT-based Peer-to-Peer framework.According to the feature of the Echord,all grid nodes are organized into ring topology.The grid resources are described as the RDF form and the resource information are released to different grid nodes.We presented the resource discovery algorithm based on Echord protocol.Theoretical analysis and simulations indicate that the proposed approach can improve average query length,message broadcast performance and random query success ratio in the process of grid resource discovery.