Lanternfish: Better random networks through optics

Abstract

Current random datacenter network designs, such as Jellyfish, directly wire top-of-rack switches together randomly, which is difficult even when using best-practice cable management techniques. Moreover, these are static designs that cannot adapt to changing workloads. In this paper, we introduce Lanternfish, a new approach to building random datacenter networks using an optical ring that significantly reduces wiring complexity and provides the opportunity for reconfigurability. Unlike previous optical ring designs, Lanternfish does not require wavelength planning because it is specifically designed to provide random connectivity between switches. This design choice further reduces the difficulty of deploying a Lanternfish network, making random datacenter networks more practical. Our experimental results using both simulations and network emulation show that Lanternfish can effectively provide the same network properties as Jellyfish. Additionally, we demonstrate that by replacing passive optical components with active optical components at each switch, we can dynamically reconfigure the network topology to better suit the workload while remaining cost competitive. Lanternfish is able to construct workload specific topologies that provide as much as half the average pathlength than a Jellyfish deployment with twice as many switch-to-switch connections.