A new Zigzag MDS code with optimal encoding and efficient decoding

摘要

Distributed file system has emerged in recent years as an efficient solution to store the large amount of data produced anytime and anywhere. In order to guarantee data reliability, it is necessary to introduce redundancy to the storage systems. Compared to simple replication, practical systems are increasingly adopting erasure codes for better storage efficiency. However, traditional erasure codes such as maximum-distance-separable (MDS) codes, are designed over a large finite field, which inevitably hinders the wide implementation of erasure codes. In this paper, we propose a new family of MDS codes with high computation efficiency. More specifically, only XOR operation is included in the encoding process to generate parity blocks. Upon failure of a storage node, we use the efficient Zigzag decoding method to recover the failed blocks, which achieves the optimal encoding and an efficient decoding. Furthermore, we implement the proposed codes in a distributed file system, and the results show the high performance of the new codes.