EC-FRM: An Erasure Coding Framework to Speed Up Reads for Erasure Coded Cloud Storage Systems

Abstract

With the reliability requirements increasingly important, erasure codes have been widely used in today's cloud storage systems because they achieve both high reliability and low storage overhead. However, the performance for most existing erasure codes can be further improved on both normal reads to user's data without device failures and degraded reads under device failures, which are crucial in cloud storage systems. In this paper, we propose an erasure coding framework named EC-FRM to integrate existing codes in order to improve the read performance. The constructed code over EC-FRM named EC-FRM-Code, which keeps most of wonderful properties of the integrated code and achieves good performance on both normal reads and degraded reads. We transform Reed-Solomon code and LRC code to EC-FRM-RS and EC-FRM-LRC respectively, and then conduct a series of experiments to evaluate their read performance. The results show that EC-FRM-RS code gains 19.2% to 33.9% higher normal read speed and 9.1% to 9.9% higher degraded read speed than standard Reed-Solomon code, while EC-FRM-LRC code owns 23.5% to 46.9% higher normal read speed and 3.3% to 12.8% higher degraded read speed than standard LRC code.