Towards End-to-End Quality of Service: Controlling I/O Interference in Shared Storage Servers

Due to the imperative need to reduce the costs of management, power and cooling in large data centers, operators multiplex several concurrent applications on each physical server of a server farm connected to a shared network attached storage. Determining and enforcing per-application resource quotas on the fly in this context poses a complex resource allocation and control problem spanning many levels including the CPU, memory and storage resources within each physical server and/or across the server farm. This problem is further complicated by the need to provide end-to-end Quality of Service (QoS) guarantees to hosted applications. In this paper, we introduce a novel approach towards controlling application interference for resources in shared server farms. Specifically, we design and implement a minimally intrusive method for passing applicationlevel QoS requirements through the software stack. We leverage highlevel per-application requirements for controlling I/O interference between multiple database applications, by QoS-aware dynamic resource partitioning at the storage server. Our experimental evaluation, using the MySQL database engine and OLTP benchmarks, shows the effectiveness of our technique in enforcing high-level application Service Level Objectives (SLOs) in shared server farms.