Towards minimum loss job routing to parallel heterogeneous multiserver queues via index policies

► We consider a model for minimum loss job routing to parallel finite-buffer queues. ► The model applies to load balancing in Web server clusters with QoS delay targets. ► A new index policy based on restless bandit (RB) indexation is proposed. ► New results for the index policy based on one-step policy improvement are given. ► The RB index policy is shown to be near optimal and to outperform other policies.