Towards fair sharing of block storage in a multi-tenant cloud
Xing Lin, Yun Jie Mao, Feifei Li, Robert Ricci · 2012
A common problem with disk-based cloud storage ser-vices is that performance can vary greatly and become highly unpredictable in a multi-tenant environment. A fundamental reason is the interference between workloads co-located on the same physical disk. We observe that dif-ferent IO patterns interfere with each other significantly, which makes the performance of different types of work-loads unpredictable when they are executed concurrently. Unpredictability implies that users may not get a fair share of the system resources from the cloud services they are using. At the same time, replication is commonly used in cloud storage for high reliability. Connecting these two facts, we propose a cloud storage system designed to min-imize workload interference without increasing storage costs or sacrificing the overall system throughput. Our design leverages log-structured disk layout, chain repli-cation and a workload-based replica selection strategy to minimize interference, striking a balance between perfor-mance and fairness. Our initial results suggest that this approach is a promising way to improve the performance and predictability of cloud storage. 1