云计算环境下的分布存储关键技术

云计算作为下一代计算模式,在科学计算和商业计算领域均发挥着重要作用,受到当前学术界和企业界的广泛关注.云计算环境下的分布存储主要研究数据在数据中心上的组织和管理,作为云计算环境的核心基础设施,数据中心通常由百万级以上节点组成,存储其上的数据规模往往达到PB级甚至EB级,导致数据失效成为一种常态行为,极大地限制了云计算的应用和推广,增加了云计算的成本.因此,提高可扩展性和容错性、降低成本,成为云计算环境下分布存储研究的若干关键技术.针对如何提高存储的可扩展性、容错性以及降低存储的能耗等目标,从数据中心网络的设计、数据的存储组织方式等方面对当前分布存储的关键技术进行了综述.首先,介绍并对比了当前典型的数据中心网络结构的优缺点；其次,介绍并对比了当前常用的两种分布存储容错技术,即基于复制的容错技术和基于纠删码的容错技术；第三,介绍了当前典型的分布存储节能技术,并分析了各项技术的优缺点；最后指出了当前技术面临的主要挑战和下一步研究的方向.

Key Technologies of Distributed Storage for Cloud Computing

Considered as the next generation computing model,cloud computing plays an important role in scientific and commercial computing area and draws great attention from both academia and industry fields.Under cloud computing environment,data center consist of a large amount of computers,usually up to millions,and stores petabyte even exabyte of data,which may easily lead to the failure of the computers or data.The large amount of computers composition not only leads to great challenges to the scalability of the data center and its storage system,but also results in high hardware infrastructure cost and power cost.Therefore,fault-tolerance,scalability,and power consumption of the distributed storage for a data center becomes key part in the technology of cloud computing,in order to ensure the data availability and reliability.In this paper,a survey is made on the state of art of the key technologies in cloud computing in the following aspects: Design of data center network,organization and arrangement of data,strategies to improve fault-tolerance,methods to save storage space,and energy.Firstly,many kinds of classical topologies of data center network are introduced and compared.Secondly,kinds of current fault-tolerant storage techniques are discussed,and data replication and erasure code strategies are especially compared.Thirdly,the main current energy saving technology is addressed and analyzed.Finally,challenges in distributed storage are reviewed as well as future research trends are predicted.