Energy management for a real-time shared disk cluster

Energy management for cluster architectures has become an important design issue. In this paper, we propose a dynamic reconfiguration algorithm, named DRA-SD, to reduce the energy consumption of a real-time shared disk (SD) cluster. DRA-SD consolidates cluster load on a subset of nodes if the quality of service (QoS) is met. Remaining nodes are deactivated so that they can stay at a low-power state. When the load increases again, DRA-SD dynamically activates additional nodes. Unlike previous algorithms proposed for web server clusters, DRA-SD exploits the inherent characteristics of SD cluster to reduce the internode interference and to improve the processing capacity of a given cluster configuration. This enables DRA-SD to meet the QoS constraint while consuming minimal energy. Experiment results show that DRA-SD can save energy significantly under a wide variety of transaction workloads and node characteristics.