AWR-RAID:一致性保证的纠删码RAID系统  

AWR-RAID:Erasure Coding System with Data Consistency Guaranteed

作　　者：贾思懿 刘振军[1] 刘建亮[1,2] 方沛[1,2] 董欢庆[1] 

机构地区：[1]中国科学院计算技术研究所,北京100190 [2]中国科学院大学,北京100049

出　　处：《小型微型计算机系统》2017年第7期1658-1664,共7页Journal of Chinese Computer Systems

基　　金：中国科学院先导专项基金项目(XDA06010401)资助;天津市科技计划项目(15ZXDSGX00020)资助

摘　　要：信息技术正在从以计算设备为核心的计算时代进入到以数据为核心的存储时代.数据量和数据价值的增加,对存储系统的容量、成本、访问性能和数据可靠性等方面提出了更高的要求.为减小冗余数据开销并保证数据的可用性和可靠性,采用纠删码技术已成为业界的发展趋势.数据一致性是纠删码存储系统的本质属性,保证了数据的可靠性和可用性,高效保证纠删码数据的一致性是纠删码系统的关键.提出"写后重映射"存储模型(After Write Remapping,AWR)和事务实现方法,保证了纠删码数据的一致性.AWR模型为纠删码数据的更新过程提供原子性和持久性,采用非原位更新和原子重映射机制保证了更新过程中数据的一致性,具有通用性好、存储开销低和事务性能高的特点.经过理论分析和实际测试验证,AWR事务存储模型带来的纠删码存储系统读性能损失低于1%,64KB及以上粒度的写性能损失低于3%,高效地保证了纠删码数据的一致性.Information technology is entering a storage era cored on data from the calculating era cored on calculating device. With the growth of data in quantity, increasing of data value, higher requirements have been proposed for capacity, cost,visiting capability, and data reliability of storage system. In order to reduce the cost of redundant data and ensure data reliability and availability, it is a trend in the industry to take erasure codes technique. Data consistency is the essential attributes of erasure coding system,which ensures the reliability and availability of data. Therefore, maintaining consistency of erasure coding data is the key to realization of erasure coding system. The ＂After-writing remapping＂ storage mode （AWR） and transaction realization methods are proposed which ensured the consistency of data. AWR provided atomicity and persistence to the updating process of erasure coding data; meanwhile it adopted long-distance updating and atomic remapping mechanism, which kept the data consistency in updating process ,having the advantages like good generality, low storage cost and high transaction capability. Theoretical analysis and practical test have proved that the loss brought by AWR transaction storage mode to the reading capability of erasure coding storage system was less than 1%, and writing capability loss for system 64KB and above were less than 3% ,ensured the consistency of erasure coding data with high efficiency.

关 键 词：纠删码 一致性 事务 高效 

分 类 号：TP316[自动化与计算机技术—计算机软件与理论]