Performing Load Balancing under Constraints

TL;DR

This paper extends load balancing policies like JSQ to include network-imposed constraints using constrained MDPs, resulting in safe, efficient policies that minimize system occupancy.

Contribution

It introduces a novel framework for load balancing under constraints, developing policies that are both safe and effective, unlike existing methods.

Findings

Policies are provably safe.

Policies effectively minimize system occupancy.

Numerical results validate performance under various settings.

Abstract

Join-the-shortest queue (JSQ) and its variants have often been used in solving load balancing problems. The aim of such policies is to minimize the average system occupation, e.g., the customer's system time. In this work we extend the traditional load balancing setting to include constraints that may be imposed, e.g., due to the communication network. We cast the problem into the framework of constrained MDPs, enabling the consideration of both action-dependent constraints, such as, e.g, bandwidth limitation, and state-dependent constraints, such as, e.g., minimum queue utilization. Unlike the state-of-the-art approaches, our load-balancing policies, in particular JSED-$k$ and JSSQ, are both provably safe and yet strive to minimize the system occupancy. Their performance is tested with extensive numerical results under various system settings.