分布式存储系统中基于部分重复循环码的局部修复码构造

Construction of locally repairable codes based on fractional repetition cyclic codes in distributed storage systems

为了进一步优化分布式存储系统故障节点修复的磁盘I/O开销和修复局部性,提出一种基于部分重复循环码的局部修复码方法。首先构造部分重复循环码(FRCC);然后在此基础上划分局部修复组;最终得到相应的局部修复码,且局部修复组内故障节点可以通过相邻节点实现协作修复,以确保较低的磁盘I/O开销和修复局部性。性能分析以及实验仿真表明,采用基于部分重复循环码的局部修复码,单节点故障的修复局部性恒为2,并且可以快速实现多个故障节点的数据重构;与三副本复制策略、简单再生码以及基于传统FRC的局部修复码相比,基于部分重复循环码的局部修复码具有更低的修复带宽开销和修复局部性,修复效率更高。

In order to optimize the disk I/O overhead and repair locality for repairing failed node in distributed storage systems,locally repairable codes based on fractional repetition cyclic codes( FRCC) is proposed in this paper. Specifically,FRCC is constructed at first,and then the local repair groups are divided on the basis. Finally,the corresponding locally repairable codes are obtained,and the failed nodes can be repaired by the neighboring nodes in the local repair group to ensure lower disk I/O overhead and repair locality.Performance analyses and simulation results show that,the repair locality of a single node failure is always 2 when the locally repairable codes based on FRCC are adopted in distributed storage systems,and the data of multiple failed nodes can be reconstructed quickly.Compared with three-copy replication,simple regenerating codes and locally repairable codes based on traditional fractional repetition codes( FRC),the locally repairable codes based on FRCC have lower bandwidth overhead and repair locality,as well as higher repair efficiency.