Web File System Based On Dynamic Replica Mechanism

With the advent of the era of Web2.0 and the popularity of smart phones, the production of unstructured data has become easier, the scale of network data has increased gradually. Network applications usually use web file system to manage a large number of network files. In web file system, web files are dispersed in different hosts, but the access frequency of different file is not the same, which causes load imbalance and user experience decreases. How to make full use of network host resources, reduce the load imbalance, and improve the quality of service has become a new research direction.In this paper, an improved web file system based on dynamic replica mechanism is proposed. Dynamic replication technology can allocate server resources dynamically. It can provide more copies for the document which is accessed more to achieve load balancing, improve system performance and improve the user experience. The main contents are as follows:In this paper, the dynamic replica technique is analyzed and optimized according to the application scenarios. The hot files algorithm are discussed, the deficiency in the performance of the algorithm was analyzed. To reduce memory overhead and reduced the computational complexity degree, the algorithm was optimized by grouping mechanism and dispersion statistics. In addition, the scheduling strategy in the dynamic replica technique is explained, and the role of the host is defined in the project. And then a scheduling strategy is proposed which works by weakening the difference between the two poles of the load.Then the improved dynamic replica technique is applied to the web file system. Due to the dynamic replication mechanism need statistical file access frequency and make adjustments to the replica, so in this paper, combined with web technology the specific design was given including system architecture, system metadata and system scheduling strategy. And then, the filter, scheduling logic, business logic and so on are realized by programming in the web file system.Finally, the improved web file system is deployed, and the system test is done by writing a simple test tool. Through the test, it is found that the improved web file system can support the dynamic replica mechanism, it can adjust the replica of the file according to the access situation, and the system performance was improved.