The Improved Research of Chord Based on File-Partition Replication Strategy

In large scale structured p2p network system, in order to improve the data availability and reduce the effect caused by one exception quitting, the method of replicating data actively to other nodes is used to increase data redundancy. To reduce the replication cost, this paper presents a detailed description of replication strategy based on file-partition. The data file is partitioned into pieces which will then be distributed and copied within a collection of selected nodes before hand. This strategy can effectively utilize the bandwidth and obviously reduce the replication time. Chord locating the lookup service by a pair of (k, v) is based on singular DHT structure. In most case, Chord stores file resource in one node without describing how to increase data redundancy. When the node quits unconventionally, all the records and resources will fail automatically. Whatpsilas more, adding and quitting nodes frequently will greatly influence the performance of the network. In order to solve this problem, a method that the chord is based on a file-partition replication strategy is proposed; also the resource mapping function which is under the chord structure is improved.