Date Added: May 2012
Modern datacenters support a large number of applications with diverse performance requirements. These performance requirements are expressed at the application layer as high-level Service-Level Objectives (SLOs). However, large-scale distributed storage systems are unaware of these high-level SLOs. This lack of awareness results in poor performance when workloads from multiple applications are consolidated onto the same storage cluster to increase utilization. In this paper, the authors argue that because SLOs are expressed at a high level, a high-level control mechanism is required. This is in contrast to existing approaches, which use block- or disk-level mechanisms.