Research On The Replica Consistency Of P2P Distributed Storage Systems

P2P is an important network computing technology，there are lots of researches onit and it has been applied in many fields. Building large-scale P2P distributed storagesystem can support the massive data and the user’s storage requirements and datasharing. Peer-to-peer computing is a hot research topic in recent years，and using P2Ptechnology to build the storage system is a hot spot in the hot topic.In order to better manage the massive stored data more，Storage system adopts datareplication technology. Though data replication can increase the availability andstability，it poses a problem for the consistency in data storage system management.Because P2P systems is highly dynamic and distributed，and the size is very large，theseproblems would bring challenges to the updating for data storage system.In order to solve these problems，this paper conducts an in-depth study on thereplica placement algorithm of P2P distributed storage system and its consistencymaintenance problem. Firstly，this paper introduces the research background and thecurrent study at home and abroad，then describes the distributed storage systems indetails，also gives detailed description of the concept and characteristics of P2P-baseddistributed storage system. Finally，in-depth analysis of the performance and reliabilityissues of P2P storage system is given based on distributed，studies the replica placementalgorithm. A certain number of copies and the appropriate replica placement can greatlyimprove the availability of storage systems and reduce system response time to improvequery efficiency. However，traditional researches mostly focus on the locating andsearching of a replica in the P2P distributed system，through the optimization of thesearch algorithm to guarantee the system’s efficiency. But the latest study shows thatoptimization searching algorithm can only be applied to usage in a static system，forthese systems have not got frequently updated resources，and often access the resourcein read-only form. But with the emergence of new applications，read-only resource filescan not meet the needs of users，they must be converted to read-write form. So，ensuringthe consistency of replica of every data is not only the essence of storage system，butalso is the very pressing issue to ensure the well development of P2P storage system. If the storage system can only share static files but can’t update stored files at any time，thetechnology will be obsolete immediately. In addition，new business of P2P storage alsoneeds to be able to update files dynamically.According to the above mentioned discoveries，this paper studies the replicaplacement algorithm， and explores the stripe placement algorithm starting fromanalyzing random and order placement algorithms. Finally，for the P2P data consistencymaintenance，this paper presents a maintenance strategy，which is for the replicaspreading tree of structured storage system. The strategy is to store the relevantinformation of file replica in the binary tree and maintain replica consistency bysubscribing and unsubscribing algorithm. Experiments show that this strategy caneffectively reduce maintenance costs.