Study On DHT Based Open P2P Cloud Storage Services Systems

As a model of supercomputing based on virtualization, cloud computing provided the IaaS, PaaS, SaaS services via Internet, which will integrate all the large-scale and extensible distributed computing resources such as computing, storage, data and application for cooperative work. It's an entirely new Internet application mode and will be the leading way to access services and information in the near future. As a new concept, cloud storage was an extension of cloud computing research focus, which was given more and more attention from academia and industry. Cloud storage service system provides an effective solution to mass network data storage in the case of maximize cost savings, providing a perfect backup, disaster recovery data center.The concept of cloud storage was proposed in not a long time, but they have played an important role in solving problems of large-scale unstructured data of online storage, query and backup.As the latest development of the distributed storage technology, Cloud storage is the product of the integration of distributed storage and virtualization technologies. Cloud storage is a method that allows you to use storage facilities available on the Internet. Focused on the P2P cloud storage systems, the following academic achievements results were made around its architecture, redundant mode, intrusion detection, reputation mechanism.(1)Relative to the current Master/Slave computing model cloud storage file systems, including GFS, HDFS, Sector and KFS, an open Peer-to-Peer Cloud Storage Services Systems based on DHT were proposed, and we constructed a prototype system named MingCloud based on Kademlia algorithm. Highlighting the system security and reliability of data, our system can provide basic data storage, read, delete, search and other storage services. The results from a simulation experiment show that the system has high availability and performance, which can be actually applied to the Internet dynamic and open environment after improving and optimizing, and to provide higher quality of cloud storage service.(2)Focused on redundancy scheme selection and design of the storage system, comprehensive and objective assessments were given between full redundancy and Erasure code. Our experiment used the Cauchy Codes as coding algorithm to assess the system from many aspects, including the impact of K bucket size on system availability, the impact of File block number on system availability, comparison of system availability under same redundancy. Compared with the redundant mode of complete copy, the Erasure Code model provided more satisfactory system availability, and more suitable to apply to our Cloud Storage System.(3)To address the insider threat more effectively in P2P Cloud Storage System, an adaptive trust alert correlation P2P overlay IDS was proposed. Base on JXTA P2P framework, a P2P overlay IDS prototype system was implemented, and its effectiveness to prevent the spread of a real Internet worm was evaluated over an emulated network. The experiment results show the P2P overlay IDS significantly increases the overall survival rate of vulnerable peers in the network.(4)According to the system R&D needs, reputation mechanisms MingCredit were designed for our Peer-to-Peer cloud storage services systems based on DHT, specifically including the calculation of reputation degree, trust model design, work process of reputation mechanisms, safety analysis. Simulation results show that the mechanisms of this model provide a high degree of effectiveness and robustness. Meanwhile, the reputation model can effectively protect honest nodes, reduce the trust value of malicious nodes, and restrain malicious behaviors.Based on DHT, a feasible solution of distributed cloud storage services system was put forward. Simulation results shows the proposed prototype system have good scalability, reliability, and security.