The heavy-tailed nature of Internet flow sizes, web pages and computer files can cause non-
preemptive scheduling policies to have a large average response time. Since there are
numerous communication and distributed processing systems where preempting jobs can
be quite expensive, reducing response times under this constraint is a pressing issue. One
proposal for tackling non-preemption is through the use of multiple servers: classify jobs
according to size and assign a server to each class. Unfortunately, in most systems of …