Repair Locality With Multiple Erasure Tolerance
Repair Locality With Multiple Erasure Tolerance
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DOI：
10.1109/tit.2014.2351404
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发表时间：
2013-06
影响因子：
2.5
通讯作者：
Anyu Wang;Zhifang Zhang
中科院分区：
文献类型：
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作者：
Anyu Wang;Zhifang Zhang
在分布式存储系统中，具有局部性r的擦除代码是首选的，因为可以通过在其他R访问其他坐标来局部修复坐标，从而大大降低了磁盘I/O的复杂性。当某些R坐标也被删除以克服此问题时，我们提出（R，δ）C-locatie提供δ-1不重叠的局部修复组，而不是R的坐标。可以在任何线性的[n，k]代码（r，δ）C -location中忍受δ-1擦除的最小距离。当n≥k（R（δ -1） + 1）。尽管Prakash等人定义的位置（R，δ）提供了与我们的定义相同的位置和局部修复耐受性，但代码为（R，Δ） C-Locality采用绑定尤其在最小距离中具有更大的优势。信息率接近1。
In distributed storage systems, erasure codes with locality r are preferred because a coordinate can be locally repaired by accessing at most r other coordinates which in turn greatly reduces the disk I/O complexity for small r. However, the local repair may not be performed when some of the r coordinates are also erased. To overcome this problem, we propose the (r, δ)c-locality providing δ-1 nonoverlapping local repair groups of size no more than r for a coordinate. Consequently, the repair locality r can tolerate δ -1 erasures in total. We derive an upper bound on the minimum distance for any linear [n, k] code with information (r, δ)c-locality. Then, we prove existence of the codes that attain this bound when n ≥ k(r(δ - 1) + 1). Although the locality (r, δ) defined by Prakash et al. provides the same level of locality and local repair tolerance as our definition, codes with (r, δ)c-locality attaining the bound are proved to have more advantage in the minimum distance. In particular, we construct a class of codes with all symbol (r, δ)c-locality where the gain in minimum distance is Q(√r) and the information rate is close to 1.