Capacity Aware Adaptive Routing

Learn about Meta's advanced network routing optimization techniques in this 20-minute conference talk from the Open Compute Project. Discover how Meta addresses the limitations of current Adaptive Routing Schemes in large-scale backend networks, where local load awareness proves insufficient for exponentially growing topologies. Explore the challenges posed by parallel links, shallow buffer switches, and remote link failures that can cause congestion and performance degradation without losing network reachability. Understand Meta's innovative solution that combines remote capacity information with local-congestion-aware spray techniques to create a dynamic load balancing scheme based on end-to-end network capacity. Examine the algorithms developed for efficiently merging ARS groups and the strategic use of non-load-aware ECMP spray groups to overcome scaling challenges, ensuring more efficient traffic distribution and minimizing the impact of link failures on overall network performance.