摘要
再生码通过允许节点传送所存数据的线性组合并增加修复入度,显著地降低了修复带宽,但是增加了参与节点数和磁盘I/O。针对这一缺点,首先通过分析再生码的阈值函数得到一个定理,指出了降低阈值函数的一个充要条件;然后根据该定理构造出了结合复制方式的新再生码。新再生码不增加修复入度也能降低阈值函数,与再生码类似,也有两个特殊点——最小存储量点和最小修复带宽点。通过对两个特殊点的定性与定量分析,发现新再生码可以利用复制来降低单节点修复带宽,并且平均修复带宽和平均磁盘I/O也会减少。
By allowing storage nodes to send linear combinations of their data to the newcomer and increasing repair degree, regenerating codes significantly reduce repair bandwidth overhead. But,they sacrifice repair locality and disk I/O. Against this disadvantage,this paper first gave a theorem which indicated the necessary and sufficient condition to reduce the threshold function in regenerating codes by analyzing the structure of threshold function, then introduced new regenerating codes combined with rephcation based on the theorem. New regenerating codes can reduce threshold function without increasing repair degree, and have also 2 special points-minimum-storage point and minimum-bandwidth point. After qualitative and quantitative analysis, it shows that new regenerating codes can reduce repair bandwidth overhead of per node by replication, and reduce mean repair bandwidth and disk I/O.
出处
《计算机应用研究》
CSCD
北大核心
2017年第1期102-106,共5页
Application Research of Computers
关键词
复制
再生码
修复入度
修复带宽
磁盘I/O
replication
regenerating codes
repair degree
repair bandwidth
disk I/O
