Preliminary Performance Analysis of Multi-rail Fat-Tree Networks
Noah Wolfe, Misbah Mubarak, Nikhil Jain, Jens Domke, Abhinav Bhatelé, Christopher D. Carothers, Robert B. Ross · 2017
Among the low-diameter, high-radix networks beingdeployed in next-generation HPC systems, dual-rail fat-treenetworks are a promising approach. Adding additional injectionconnections (rails) to one or more network planes allows multirailfat-tree networks to alleviate communication bottlenecks. These multi-rail networks necessitate new design considerations, such as routing choices, job placements, and scalability of rails. We extend our fat-tree network model in the CODES parallelsimulation framework to support multi-rail and multi-planeconfigurations in addition to different types of static routing, resulting in a powerful research vehicle for fat-tree network analysis. Our detailed packet-level simulations use communicationtraces from real applications to make performance predictionsand to evaluate the impact of single-and multi-rail networks inconjunction with schemes for injection rail selection and intraplane routing.