Optimal placement for repair-efficient erasure codes in geo-diverse storage centres

Abstract

Erasure codes are increasingly being used by storage providers to reduce the cost of reliably storing large volumes of data. As compared to the default mechanism of triple replication, erasure codes result in optimal storage efficiency, but require significant network and disk usage during repair of failed data. The repair process is particularly complicated for storage clusters with data centres spread across a wide geographical area. For such geo-diverse clusters, the recovery performance of the code used depends more on the network throughput and latency than on the computations required for decoding. Hence, the recovery performance of most erasure codes can be improved if the surviving b..