With the practical application of erasure codes in distributed storage systems, erasure codes provide better storage efficiency for storage systems, but when nodes are lost, more network transmission bandwidth overhead compared with traditional replica technology becomes a key factor causing system performance bottlenecks. In order to solve the impact of high bandwidth overhead of MDS coding on system performance, a new type of coding scheme, packet coding, is applied in distributed storage systems. Compared with traditional MDS coding, it can effectively reduce the amount of data transmission during node repairing, thus reducing the network bandwidth demand. This paper proposed a HLRC(hierarchical local repair codes) based on the hierarchical expansion of Pyramid codes. HLRC introduced a hierarchical coding model compared to LRC, which constructed the original data blocks as a coding matrix, and coded according to the hierarchical levels to generate local checksum blocks with different ranges of data blocks. Each hierarchy contained a different number of data blocks, which ensured low repair cost and high storage efficiency when repairing nodes. HLRC had additional checksum block redundancy compared to Pyramid codes, which reduced the recovery overhead in the event of checksum block errors and multi-node errors. Experimental results in a Ceph-based distributed storage system show that HLRC can reduce single-node repair overhead by up to 48.56% and multi-node repair overhead by up to 25% compared to Pyramid codes and other packet codes.

[2023-11-14] Accepted Paper /doc/2023.08.0399/v1

[2024-05-05] Printed Article /doc/2023.08.0399/v2