Coded sparse matrix computation schemes that leverage partial stragglers

Coded matrix computation utilizes concepts from erasure coding to mitigate the effect of slow worker nodes (stragglers) in the distributed setting. While this is useful, there are issues with applying, e.g., MDS codes in a straightforward manner for this problem. Several practical scenarios involve sparse matrices. MDS codes typically require dense linear combinations of submatrices of the original matrices which destroy their inherent sparsity; this leads to significantly higher worker computation times. Moreover, treating slow nodes as erasures ignores the potentially useful partial computations performed by them. In this work we present schemes that allow us to leverage partial computation by stragglers while imposing constraints on the level of coding that is required in generating the encoded submatrices. This significantly reduces the worker computation time as compared to previous approaches and results in improved numerical stability in the decoding process. Exhaustive numerical experiments support our findings.