Methods of Locating Mirror Servers with High Connectivity and Small Distances

The server mirroring method has extensively used as the technology for contents delivery networks. Several mirror servers that serve same contents are located in a network, and an access is navigated to one of the mirror servers based on the delay time and the load balance. The location of the mirror servers with high reliability against a failure and small delay times of accesses is important. In this paper, we deal with the server location problem, which determines the location of the mirror servers that satisfies the following two constraints: the reachability to at least one server is guaranteed even if a link fails, and the maximum of the sum of the distances to the servers is restricted. We propose two heuristic algorithms for the problem and evaluate the algorithms by applying to some real networks. The results show that the algorithms perform well.