A Content Distribution Network (CDN) can be defined as an overlay system that replicates
copies of contents at multiple points of a network, close to the final users, with the
objective of improving data access. CDN technology is widely used for the distribution of
large-sized contents, like in video streaming. In this paper we address the problem of
finding the best server for each customer request in CDNs, in order to minimize the
overall cost. We consider the problem as a transportation problem and a distributed
algorithm is proposed to solve it. The algorithm is composed of two independent phases: a
distributed heuristic finds an initial solution that may be later improved by a
distributed transportation simplex algorithm. It is compared with the sequential version
of the transportation simplex and with an auction-based distributed algorithm.
Computational experiments carried out on a set of instances adapted from the literature
revealed that our distributed approach has a performance similar or better to its
sequential counterpart, in spite of not requiring global information about the contents
requests. Moreover, the results also showed that the new method outperforms the
based-auction distributed algorithm.