In cloud computing,the number of replicas and deployment strategy have extensive impacts on user's requirement and storage efficiency.Therefore,in this paper,a new definition of file access popularity according to users' preferences,and its prediction algorithm are provided to predict file access trend with historical data.Files are sorted by priority depending on their popularity.A mathematical model between file access popularity and the number of replicas is built so that the reliability is increased efficiently.Most importantly,we present an optimal strategy of dynamic replicas deployment based on the file access popularity strategy with the overall concern of nodes' performance and load condition.By this strategy,files with high priority will be deployed on nodes with better performance therefore higher quality of service is guaranteed.The strategy is realized in the Hadoop platform.Performance is compared with that of default strategy in Hadoop and CDRM strategy.The result shows that the proposed strategy can not only maintain the system load balance,but also supply better service performance,which is consistent with the theoretical analysis.
针对当前的云计算服务器缺少对不稳定数据的识别与检测,设计并实现一种云服务器中不稳定数据挖掘系统。介绍系统的总体结构,利用数据采样预处理模块实现从源数据到挖掘数据的映射,完成离散化、数据过滤等处理过程。依据2.0 mm ERmet Hard Metric连接器,采用Rapid IO协议,通过接口模块完成数据间的传输,以达到信号传输效率与稳定性的要求。通过数据挖掘模块对云服务器中不稳定数据的确认与挖掘,将挖掘结果传输至控制模块进行处理。软件设计过程中,对云服务器中不稳定数据挖掘系统进行了详细地分析,并给出不稳定数据挖掘的实现过程以及系统部分程序代码。实验结果表明,所设计的系统具有很高的实用性和可靠性。
