X再生码:一类适用于云存储的准确修复编码  

X REGENERATING CODES: A CLASS OF ACCURATE REPAIR CODES FOR CLOUD STORAGE

作　　者：李小兵[1,2] 许胤龙[1,2] 林一施 项利萍[1,2] 

机构地区：[1]中国科学技术大学计算机科学与技术学院,安徽合肥230027 [2]安徽省高性能计算重点实验室,安徽合肥230027

出　　处：《计算机应用与软件》2014年第8期241-244,248,共5页Computer Applications and Software

基　　金：国家自然科学基金项目(61073038);安徽省科技攻关项目(1206C0805003)

摘　　要：通过将(n,k)-RS编码和X编码结合,为云存储系统设计一类新的准确修复编码——X再生码。它具有容忍n-k个节点故障的可靠性,并且当系统中单个或者两个节点出现故障时,仅需从少量的节点下载数据块,使用简单的异或运算即可修复。对X再生码的存储代价、修复带宽、修复局部性(修复过程中需要连接的节点数)和编码率进行分析,并与RS编码、SRC以及LRC进行对比。结果显示,X再生码在一个或者两个节点故障时,修复局部性以及修复带宽上都具有显著的优势,并能达到任意高的编码率。We design for cloud storage a new class of accurate repair codes——X regenerating codes by combining（n,k）-RS code with X code. It has the reliability of n- k nodes failures tolerance,moreover,when there are the failures happened involving single or two nodes in the system,it can be repaired by just downloading the data blocks from few nodes and using simple XOR operation. In this paper we analyse the storage cost,repair bandwidth,repair locality（which corresponds to the number of nodes having to be accessed during a repairing process）,and code rate for X regenerating codes,and compare them with RS code,SRC and LRC. Results indicate that X regenerating codes have significant advantages in both repair locality and repair bandwidth when repairing one or two node failures,and can achieve arbitrarily high coderates.

关 键 词：云存储 RS编码 X编码 修复局部性 

分 类 号：TP302.8[自动化与计算机技术—计算机系统结构]