Multidimensional facility location problem in Content Distribution Networks

Assignment problem in content distribution networks (CDN) is unsplittable hard-capacitated facility location problem (UHCFLP) because of underlying anycast routing protocol. We extend assignment problem in CDN to multidimensional facility location problem (MFLP). With our devised algorithm, assignment cost considers CPU utilization parameter along with request size and distance between client and server. The importance of incorporating CPU utilization parameter into assignment cost enables in real-time modeling of CDN. Therefore, additional requests are not assigned to overloaded server, even though network bandwidth is available. We observe that approximating MFLP is NP-hard without violating capacity constraints. Therefore, we relax the capacity constraints by (1 + ) factor, for some > 0. For approximating MFLP in CDN, we use tree metric and devise (1 + ) approximation algorithm which violates capacity constraints by (1 + ) factor, for some > 0.