Operating Policies for Energy Efficient Dynamic Server Allocation

Power inefficiency has become a major concern for large scale computing providers. In this paper, we consider the possibility of turning servers on and off to keep a balance between capacity and energy saving. While turning off servers could save power, it could also delay the response time of requests and therefore reduced the performance. Furthermore, as consistency is one of the most important factors for a system, we also analyse the level of consistency in the form of switching rate and fault occurrence. Several heuristic-based switching policies are introduced with a view to balance the cost between power saving, performance and consistency. Simulation results are presented and discussed with requests arriving according to a two-phase Poisson process.