A hybrid green policy for admission control in web-based applications

Using green energy to power data centers including hosting web servers were proposed as a mechanism to reduce the carbon-footprints of information and communications technology (ICT). Owning to the nature of green energy instability, data center resources (software and hardware) should be adapted autonomy. For example, web servers could be controlled to reduce energy consumption during green energy absence. A well-known proportional-integral-derivative (PID) controller could maintain the admission to web servers. However, PID controller fails to address power saving in web server operation. In this paper, we proposed a hybrid green policy controller to reduce power consumption during brown energy. A real web server has been tested with PID controller (without and with service level agreement or SLA policy) and compared with our proposed controller. About 20% of energy saving was reached with our proposed controller. The proposed controller could be easily extended to be a green admission controller used in many task computing, and cluster computing.