A New Approach to the Server Problem
Mark Chrobak, Lawerence L. Larmore · SIAM Journal on Discrete Mathematics · 1991
A new method for dealing with the server problem is proposed. The technique consists of embedding the given metric space M into a bigger metric space $\text{cl} ( M )$ called the closure of M, and allowing our servers to move in $\text{cl} ( M )$. How this technique can be applied to give a new optimal algorithm for two servers is shown.