Leveraging utilization as performance metric for CDN enabled energy efficient internet of things

Abstract With the explosive increase in Internet users and ultimately its infrastructure, efficient resource utilization has become one of the most prominent challenges in large-scale distributed systems. Content Distribution Networks (CDNs) are among the favored large-scale distributed systems that are currently handling around 40 % of the Internet traffic. In literature, different approaches have been proposed to improve the CDN performance by improving CDN utility. The CDN utility is the ratio of the served contents to the pulled contents of a surrogate server. However, the utilization of surrogate servers has largely been neglected in the previous studies. Moreover, due to the vast expansion of such systems, their energy consumption has been tremendously increased. In fact, the energy consumption of the CDN networks is directly proportional to their utilization. Therefore, it is extremely important to consider the CDN utilization while designing and evaluating the performance of CDN policies. In this work we have considered a set of request redirection policies such as load balance and load unbalance. Furthermore, infrastructure size and volume of the client request traffic is also been taken into account. Our findings represent that even if surrogate servers are poorly utilized, the CDN utility exhibits higher values in general. These finding demonstrate that CDN utility does not take into account the utilization of surrogate servers. Even if the surrogate servers are poorly utilized, the CDN utility exhibits higher values. Conclusively, evaluating the CDN performance only on the basis of CDN utility without considering utilization of surrogate servers is an inefficient approach. Therefore, we propose to consider the CDN resources utilization as an important metric while analyzing the performance of a CDN.