Re-evaluating Designs for Multi-Tenant OLTP Workloads on SSD-basedI/O Subsystems.

Multi-tenancy is a common practice that is employed to maximize server resources and reduce the total cloud operation costs. The focus of this work is on multi-tenancy for OLTP workloads. Several designs for OLTP multi-tenancy have been proposed that vary the trade-offs made between performance and isolation. However, existing studies have not considered the impact of OLTP multi-tenancy designs when using an SSD-based I/O subsystem. In this paper, we compare three designs using both open-source and proprietary DBMSs on SSD-based I/O subsystems. Our study reveals that in contrast to the case of an HDD-based I/O subsystem, VM-based designs have fairly competitive performance compared to the non-virtualized designs (generally within 1.3-2X of the best performing case) on SSD-based I/O subsystems. Whereas previous studies were based on traditional hard disk-based environments, our results indicate that switching to a pure SSD-based I/O subsystem requires rethinking the trade-offs for multi-tenant OLTP workloads.