Approximating an Energy-Proportional DBMS by a Dynamic Cluster of Nodes

The most energy-efficient configuration of a single-server DBMS is the highest performing one, if we exclusively focus on specific applications where the DBMS can steadily run in the peak-performance range. However, typical DBMS activity levels—or their average system utilization—are much lower and their energy use is far from being energy proportional. Built of commodity hardware, WattDB—a distributed DBMS—runs on a cluster of computing nodes where energy proportionality is approached by dynamically adapting the cluster size. In this work, we combine our previous findings on energy-proportional storage layers and query processing into a single, transactional DBMS. We verify our vision by a series of benchmarks running OLTP and OLAP queries with varying %intensity. degrees of parallelism. These experiments illustrate that WattDB dynamically adjusts to the workload present and reconfigures itself to satisfy performance demands while keeping its energy consumption at a minimum.