BLFair: enabling proportional I/O sharing for NVMe SSD in SPDK para-virtualization architecture

Abstract In data centers, the Storage Performance Development Kit (SPDK) para-virtualization architecture is an efficient solution for non-volatile memory express (NVMe) solid-state drive (SSD) virtualization but faces challenges in maintaining performance fairness and isolation due to storage resource competition among multi-tenants. However, the existing Quality of Service method in SPDK fails to ensure proportional I/O sharing among multi-tenants. Providing fairness and isolation while maintaining high storage utilization in SPDK remains a challenge. In this paper, we propose BLFair to address this problem. Specifically, BLFair implements proportional I/O sharing for multi-tenants in the SPDK. The design of BLFair can effectively reduce the high time complexity caused by the ordering and the overhead of maintaining the virtual clock. Moreover, BLFair allows for achieving a trade-off between proportional I/O sharing and maximizing storage utilization. BLFair also uses the lockless ring mechanism to achieve scalability for cross-core operation. We have implemented a prototype system of BLFair in SPDK. Finally, we conduct evaluations with different workloads in both local storage and NVMe over RDMA fabric environments. The results show that our method can achieve fairness and scalability. BLFair can achieve up to 7.09x 99.99th latency reduction compared to the system with no fairness. Evaluation results in realistic workloads also show that BLFair outperforms other methods.