Research On Key Technologies Of High Available P2P File Sharing System

With the rapid development of Internet, the number of Internet users grow exponentially. How to make efficient use of network resources concerns to the industry. P2P technology can reasonably and fully utilize all sorts of network resources. P2P file sharing is the earliest application and the hotspot of the P2P research. To implement a high available P2P file sharing system, many factors need to be considered, including: establishing P2P network connections, locating resources, file transfer, avoiding the hotspot, data availability. How to improve the efficiency of resources access and data availability is of particular importance.Currently, the majority of P2P file sharing system search resources using a filename based matching strategy. However, because of the diversity of network resources and the complex nature of the resource itself, filename is hard to accurately and completely describe a resource. Metadata can be thought of as"data about data". Any aspect of the file content holding users'interests can be used as metadata. In P2P file sharing system, to add a variety of metadata marking the file content in the search request, can greatly improve the accuracy of the results.In large scale of p2p network, in order to get high data availability, to actively replicate data to other nodes is used to increase data redundance. Data resources are copied as a whole file from node to node to create replicas. Using a file-partition based replication strategy, the data file is partitioned into pieces which will then be distributed and copied within a collection of node selected beforehand. It can sufficiently uses the network bandwidth, obviously reduce the replication time cost and avoid congestion. Meanwhile, Erasure code technology can also be used to increase the data redundancy. Data object is segmented and then coded into several pieces of data. Data redundancy exists between these data blocks. It effectively improves data availability and persistence in system by distributing and storing these data blocks in P2P network. It resolves the"seeding problem"in P2P file sharing system well.Based on the discussion about the key technologies, a design of high available P2P file sharing system is given.