Quota Isn't Enough: Topology Aware Scheduling on Modern GPU Clusters

A deep dive into why rack-scale NVL72 GPU hardware makes topology a scheduling requirement, and how Kueue's Topology Aware Scheduling (TAS) brings NVLink domains, rack boundaries, and PodSet slices into Kubernetes admission. Covers preferred vs. required placement, the performance cliff between NVLink and InfiniBand, and production lessons on sticky scheduling, quota debugging, fragmentation, node hot swaps, and the upstream path toward configurable preemption.