Node Affinity, Node Selector, and Other Ways to Better Control Kubernetes Scheduling

The Kubernetes scheduler plays a critical role in distributing pods across worker nodes, impacting performance and resources, and thus costs. To control the scheduler's choices, teams can use labels, node selectors, affinity, and anti-affinity. Node affinity allows specifying preferred or soft rules for scheduling pods on specific nodes or regions, while pod affinity focuses on ensuring pods run in a specific location if there are already matching pods. By combining these features with automation, teams can improve workload availability and fault tolerance, reducing costs and increasing performance.