Explicit Steady-State Approximations for Parallel Server Systems with Heterogeneous Servers
The Weighted-Workload-Task-Allocation (WWTA) routing policy is analyzed for parallel server systems with heterogeneous servers and job classes. The study proves that under relaxed conditions, the scaled workload of each server converges to an exponential random variable whose mean is explicitly determined by system parameters. This shows WWTA's robustness, as its performance limit does not depend on local scheduling policies.