云存储环境下数据副本管理策略研究

【作者】 王彩亮；

【导师】 王世普；

【作者基本信息】 云南大学 ， 软件工程， 2011， 硕士

【摘要】 随着Internet技术的快速发展,互联网上数据如海啸般迎面扑来,这直接映射人类处理数据能力的相对匮乏。云存储以简单的“按需付费”模式,为用户提供了低成、高可靠性的数据和在线存储服务。数据副本管理是任何存储系统一个重要的组成部分,对具有高可靠性、高扩展性及大容量存储等特点的云存储系统来说更为重要。目前关于云存储系统中数据副本管理的理论研究基本上处于初级阶段,因此有很多理论问题值得进一步探讨。合理的数据副本量不仅可以降低远程访问数据时的网络延迟及带宽消耗,还可以提高网络的负载均衡,同时能够提高数据的安全性、可靠性及系统的容错性等。而良好的数据副本管理策略也是提高云存储服务质量Qos的一个重要方面。以提高云存储服务质量为目的,本文主要对云存储系统数据副本管理策略中的数据副本量控制策略、数据副本选择策略、数据副本一致性维护策略等三个方面展开了研究。本文的主要创新点有：(1)提出了基于双重约束的副本创建策略和基于双重约束的副本删除策略,并详细分析推算了约束标准：可用性标准和可预测访问频度标准,给出了两者的算法描述,从理论上说明了该策略的可行性。(2)提出了基于灰预测的数据副本选择策略,用户在选择数据副本时主要考虑到数据副本响应时间,根据存储节点的历史信息预测数据副本响应时间,为用户选择最优副本提供依据,以提高云端用户的QOS。(3)提出了基于优化副本链的数据副本一致性维护策略,在创建数据副本从节点时就建立数据副本链,通过加锁机制避免数据副本节点更新时冲突问题,完成了数据副本链的建立和数据副本链的维护,分析了数据副本一致性维护过程。更多还原

【Abstract】 With the rapid development of Internet technology, the Internet data is walking towards us such as tsunami, which directly maps that the human relatively lacks the ability to deal with data.Cloud storage with a simple "on-demand"model provides users with a low-cost and high reliability of data and applications which is online storage service.Data replica management is an important component of each storage system.It is more important for cloud storage,which has the features of high reliability, versatility, scalability,large storage and so on. But the theory of the data replica management in cloud storage system is still in the initial stage.There are many issues that is worthy of further study. A reasonable amount of data copies can reduce network latency and bandwidth consumption when we access the remote data and can also increase the network load balancing. At the same time is can improve data security,reliability and system fault tolerance, etc. And the worthy of data replica management is an important aspect to improve the quality of cloud service Qos.In order to improve the quality of cloud storage services, this paper studys in three aspects. They are the copy controlling strategy, replicas creation strategies and replicas deletion strategies. The main innovations are as follows.(1) This paper proposes replicas creation strategies based double bind and replicas deletion strategiess based double bind. And it has detailed analysised the constraint criteria:the standard of ailability and the standard of access to the frequency, giving both the algorithm description.(2) This paper has analyzed and summarized the research status of replicas selection strategies, has putted forward my own replicas selection strategies based on Grey selection strategy after analysising the basis of replicas selection strategies,and has derived the prediction equation of data copy.(3) Replicas consistency strategies ia an important aspect of ensureing the data available.After Analyzing and summarizing relevant academic research,this paper has proposed the replicas consistency strategies based on optimization data copy chain, has created the replicas chain and maintenanced the replicas chain,and has analysised the process of maintenancing replicas chain.更多还原