Efficient Repair of (k+2, k) Degraded Read Friendly MDS Array Codes With Sub-packetization 2

TL;DR

This paper introduces two new constructions of degraded read friendly MDS array codes with minimal repair bandwidth and flexible repair mechanisms, suitable for any code length and small finite fields.

Contribution

It presents the first constructions of DRF MDS array codes with sub-packetization 2 that are optimal or near-optimal in repair bandwidth for arbitrary code lengths.

Findings

First construction achieves minimal repair bandwidth among existing codes.

Second construction offers flexible repair mechanisms for bandwidth or access optimization.

Applicable over small finite fields for any code length.

Abstract

In this paper, we present two constructions of degraded read friendly (DRF) MDS array codes with two parity nodes and a sub-packetization level of 2 over small finite fields, applicable for any arbitrary code length. The first construction achieves the smallest repair bandwidth among all existing constructions with the same parameters, and is asymptotically optimal with respect to the lower bound on the average repair bandwidth characterized by Zhang et al. The second construction supports two repair mechanisms, depending on whether computation within the helper nodes is permitted or not during the node repair process, thereby optimizing either the repair bandwidth or the rebuilding access.