New Construction of Locally q-ary Sequential Recoverable Codes: Parity-check Matrix Approach

This paper develops a new family of locally recoverable codes for distributed storage systems, Sequential Locally Recoverable Codes (SLRCs) constructed to handle multiple erasures in a sequential recovery approach. We propose a new connection between parallel and sequential recovery, which leads to a general construction of q-ary linear codes with information $(r, t_i, \delta)$-sequential-locality where each of the $i$-th information symbols is contained in $t_i$ punctured subcodes with length $(r+\delta-1)$ and minimum distance $\delta$. We prove that such codes are $(r, t)_q$-SLRC ($t \geq \delta t_i+1$), which implies that they permit sequential recovery for up to $t$ erasures each one by $r$ other code symbols.