A Stochastic Bin Packing Approach for Server Consolidation with Conflicts

Abstract

The energy consumption of large-scale data centers or server clusters is expected to grow sig- nificantly in the next couple of years contributing to up to 13 percent of the worlwide energy demand in 2030. As the involved processing units require a disproportional amount of energy when they are idle, underutilized or overloaded, balancing the supply of and the demand for computing resources is a key issue to obtain energy-efficient server consolidations. Whereas traditional concepts mostly consider deterministic predictions of the future workloads or only aim at finding approximate solutions, in this article we propose an exact approach to tackle the problem of assigning jobs with (not necessarily independent) stochastic characteristics to a minimal amount of servers subject to further practically relevant constraints. As a main con- tribution, the problem under consideration is reformulated as a stochastic bin packing problem with conflicts and modeled by an integer linear program. Based on real-world instances, ob- tained from a Google data center, this new approach is shown to lead to better computational results compared to a less application-oriented exact method recently proposed in the literature.