基于预算机制的非结构化P2P网络搜索算法  

Search algorithm based on budget mechanism for unstructured P2P network

作　　者：吴开贵[1] 曾家国[1] 吴长泽[1] 陈明[1] 

机构地区：[1]重庆大学计算机学院,重庆400044

出　　处：《计算机应用》2010年第5期1166-1170,共5页journal of Computer Applications

基　　金：国家自然科学基金资助项目(90818028);国家科技支撑计划项目(2008BAH37B04)

摘　　要：目前非结构化对等网络(P2P)搜索算法均采用生存时间(TTL)机制控制搜索算法的搜索深度,有效地控制了搜索消息在网络上的传播,对于盲目搜索算法控制效果较好。但是TTL机制由于存在着在相同的搜索半径内所搜索的节点数目差异巨大、各个搜索分支只能搜索同一深度等缺陷,搜索效果不稳定且不能较好支持目前主流的基于兴趣域等导向性搜索算法。针对这一问题,提出采用预算机制取代TTL机制,通过使用预算值取代传统的TTL值来控制搜索的深度和搜索节点数目,能保证搜索节点数目较固定且能实现不同搜索分支采用不同搜索深度,从而更好地支撑导向性搜索算法。实验表明,基于预算机制的非结构化P2P网络搜索算法的搜索节点数目稳定,导向性好,算法搜索效率较高。Most existing search algorithms for unstructured Peer-to-Peer （P2P） network use the Time To Live （TTL） mechanism to control the search depth of the search algorithm,which is effective in the control of the search message transmitted in the network and the blind search algorithm.However,there is a huge difference in the number of nodes searched by TTL-based algorithm even with the same search radius.And each search branch of the TTL-based algorithm can only search the same depth of the network,thus resulting in the unstable search efficiency,which can not be a good support for main current interest-domain oriented search algorithms.To solve this problem,the budget mechanism was used to replace the TTL mechanism,and the budget value was used to replace the traditional TTL value to control the depth of search and number of search nodes,which would ensure more stable number of search nodes and achieve different search branches using different search depth,give a better support for oriented search algorithms.Experiments show that search algorithm based on budget mechanism for unstructured P2P network has more stable number of searched nodes,a good orientation,and higher efficiency.

关 键 词：对等网络 搜索深度 导向性搜索 生存时间 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]