论文标题
PMDS阵列代码具有小型子包装,小维修带宽/重建访问
PMDS Array Codes With Small Sub-packetization, Small Repair Bandwidth/Rebuilding Access
论文作者
论文摘要
部分最大距离可分离(PMD)代码是一种擦除代码,将节点分为多个组,每个组都形成具有较小代码长度的MDS代码,因此它们允许仅使用几个辅助助手节点修复失败的节点,并且可以纠正所有可从理论上纠正信息的擦除模式。但是,如果组大小较大,则PMDS代码的失败节点的维修仍然需要大量通信。最近,引入了每个本地代码的PMD阵列代码,以进一步减少维修带宽。但是,它们需要广泛的重建访问权限,并且不可避免地要有显着的子包装水平。在本文中,我们首先提出了两个全球奇偶群的PMD阵列代码的构造,其子包装级别较小,并且有限字段较小。一种结构可以支持任意数量的当地平族,并且具有$(1+ε)$ - 最佳维修带宽(即$(1+ε)$乘以最佳维修带宽的乘以),而另一个则限于两个本地平等,但其重建访问权限较小,其子包装级别仅为$ 2 $ $ 2 $。此外,我们还提供了具有三个全球平等的PMD阵列代码的构造,该代码具有较小的子包装水平以及$(1+ε)$ - 最佳维修带宽,所需的有限字段明显小于现有的。
Partial maximum distance separable (PMDS) codes are a kind of erasure codes where the nodes are divided into multiple groups with each forming an MDS code with a smaller code length, thus they allow repairing a failed node with only a few helper nodes and can correct all erasure patterns that are information-theoretically correctable. However, the repair of a failed node of PMDS codes still requires a large amount of communication if the group size is large. Recently, PMDS array codes with each local code being an MSR code were introduced to reduce the repair bandwidth further. However, they require extensive rebuilding access and unavoidably a significant sub packetization level. In this paper, we first propose two constructions of PMDS array codes with two global parities that have smaller sub-packetization levels and much smaller finite fields than the existing one. One construction can support an arbitrary number of local parities and has $(1+ε)$-optimal repair bandwidth (i.e., $(1+ε)$ times the optimal repair bandwidth), while the other one is limited to two local parities but has significantly smaller rebuilding access and its sub packetization level is only $2$. In addition, we present a construction of PMDS array code with three global parities, which has a smaller sub-packetization level as well as $(1+ε)$-optimal repair bandwidth, the required finite field is significantly smaller than existing ones.