a class of msr codes for clustered distributed storage

• DOI: 10.48550/arxiv.1801.02014
• Publication Date: 2018-06-01
• Authors: Jaekyun Moon; Jy-yong Sohn; Beongjun Choi
• Keywords: FOS: Computer and information sciences; 0508 media and communications; Computer Science - Information Theory; Information Theory (cs.IT); 05 social sciences; 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology

9 pages, a part of this paper is submitted to IEEE ISIT2018<br/>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: $��=0$ and $��=1/(n-k)$, where $��$ 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 that is possible under the minimum storage overhead constraint. For the $��=0$ case, two types of locally repairable codes are proven to achieve the MSR point. As for $��=1/(n-k)$, an explicit MSR coding scheme is suggested for the two-cluster situation under the specific condition of $n = 2k$.<br/>