Research Of Redundancy Strategy For P2P Storage System Based On Hierarchy

As the user number and data volume increase significantly, the traditional C/S storagesystem can not meet the demand in aspects such as scalability,distributed content,faulttolerance and sharing ability. whereas p2p based storage system could leverage thecomputational resource and large bandwidth of the huge number of peers distributed in thenetwork, such system have the advantages in weak structure,reliability,free of single pointfailure, high throughput.so p2p storage system is lowcost, ease of scalability, extremehigh volume, high availability, high reliability and high efficency.Previous p2p storage sytem don’t consider the difference between peers and the impactof these difference,and it always trys to treat the peers as a whole and supply unitaryservice(redundancy, recovery). such approach lacks the ability to describe the dynamicnature in fine granular and can’t promise the availability. this article proposes a layeredp2p storage system which takes the dynamics nature of peers into consideration, andsuggest a concept--peer similarity to describe the peer characteristic in fine granularwhich help to supply layered service to the relevant peers.Traditional p2p storage always provide single redundancy service, replica or erasecode,whereas based on layer approach, this article suggest a multi-redundancy servicestrategy, different peer layers will be provided with specific relevant redundancy,meanwhile this article propose two extra redundancy strategies: combination of replica anderase code,two-phase erase code and have a preliminary research on these strategies.