PROBABILISTIC ANALYSIS OF THE K-SERVER PROBLEM ON THE CIRCLE

We consider a stochastic version of the k-server problem, in which k servers move on a circle to satisfy randomly generated requests. The requests are independent and identically distributed, according to an arbitrary distribution that is either discrete or continuous. The cost of serving a request is the distance that a server needs to travel in order to reach the request. The goal is to minimize the steady-state expected cost induced by the sequence of requests. We study the performance of a greedy strategy focusing, in particular, on its convergence properties and the interplay between the discrete and continuous versions of the process. Finally, we show that in the case of k = 2 servers the greedy policy is optimal.