A Class of MSR Codes for Clustered Distributed Storage
Jy-yong Sohn, Beongjun Choi, Jaekyun J. Moon · 2018
Clustered distributed storage models real data centers where intra- and cross-cluster repair bandwidths are different. In this paper, exact-repair minimum-storage-regenerating (MSR) codes achieving capacity of clustered distributed storage are designed. Focus is given on two cases:$\epsilon=0$and$\epsilon=1/(n-k)$, where$\epsilon$is the ratio of the available cross- and intra-cluster repair bandwidths,$n$is the total number of distributed nodes and$k$is the number of contact nodes in data retrieval. The former represents the scenario where cross-cluster communication is not allowed, while the latter corresponds to the case of minimum cross-cluster bandwidth allowing minimum storage overhead. For the$\epsilon=0$case, two types of locally repairable codes are proven to achieve the MSR point. As for$\epsilon=1/(n-k)$, MDS codes achieve the MSR points for$n=Lk$, where$L$is the number of clusters.