Renewable Energy Aware Data Centres: The Problem of Controlling the Applications Workload

Data centres are powerful facilities which aim at hosting ICT services. They have huge needs in term of power supply; furthermore the current trend is to prioritize the utilization of renewable energies over brown energies. Renewable energies tend to be very variable in time (e.g. solar energy), and thus renewable energy aware algorithms tries to schedule the applications running in the data centres accordingly. However, one of the main problems is that most of the time very little information is known about the applications running in data centres. More specifically, we need to have more information about the current and planned workload of an application, and the tolerance of that application to have its workload rescheduled. In this paper, we will first survey the problem of understanding, building information about and finally controlling the load generated by applications. Secondly we will propose hints of solutions for that problem.