Deadlock-Free Routing in Irregular Networks with Dynamic Reconfiguration

Abstract

High-speed local area networks (LANs) support many distributed applications. These applications require some system availability guarantees. However, LANs may change their topology due to switches and hosts being turned on/off, link remapping, and component failures. In these cases, a distributed reconfiguration algorithm is executed. This algorithm analyzes the topology, computes the new routing tables, and downloads them to the corresponding switches. Unfortunately, in most cases user traffic is stopped during the reconfiguration process to avoid deadlock. Although network reconfigurations are not frequent, they may take hundreds of milliseconds to execute, thus degrading system availability significantly. In this paper, we propose a new deadlock-free distributed reconfiguration algorithm that is able to asynchronously update the routing tables without stopping user traffic. This dynamic reconfiguration algorithm is valid for any topology, including regular as well as irregular topologies.