Chord Protocol Research And Application

As the amount of information growing surge of the internet network, peer-to-peer network breaks the traditional C/S mode to share resources and services bydirect exchange, so that all nodes in network have equal rights of freedom.Appl-ications based on P2P are rapidly penetrated into various fields, at the same time,applications with P2P technology have become a research hotspot in recentyears. Three kinds of the DFSS(distributed file sharing system) based on P2Pare developed. A centralized system provides search efficiency by storagingindex directory in a central server but poor scalability.A distributed unstructuredsystem releases the reliance on a central server, but using the broadcastmechanism to search for resources causes the problem of low efficiency ofresource search, so that it may be more suitable for a small scale network.At last,structured distributed systems provide scalable lookup services throughdistributed inverted indexs to achieve the global search. Search efficiency, aswell as semantic-based search have been become a research hotspot.Based on chord, this thesis proposed a two-layered and multi-cluster model,called TLMC-chord, that assigns nodes into clusters on the categories of sharedresources. The number of clusters depends on the number of categories,and theresource type of a physical node decides to add which cluster. Different clustersare connected by the Super Ring,which is a dynamic chord composed ofappropriate number of nodes.In this thesis, load balancing of super node is a keyissue.One objective of TLMC-chord is to provide faster queries by reducingquery space, and another objective is to meet the scalable and efficient search ofthe DFSS based on different metadata models. Through setting properties andconstructing the inverted indexs for shared files by metadata models, theTLMC-CFS is proposed in this thesis,which is a DFSS with global search.