February 21, 2026
Spot instances are unused cloud capacity sold at a steep discount – typically 60-90% off on-demand pricing. The trade-off: the cloud provider can reclaim them with minimal notice. AWS gives a 2-minute warning, GCP gives 30 seconds, and Azure varies. Running Kubernetes workloads on spot instances is one of the most effective cost reduction strategies available, but it requires architecture that tolerates sudden node loss.
February 21, 2026
Pod scheduling in Kubernetes defaults to “run anywhere there is room.” In production, that is rarely what you want. GPU workloads should land on GPU nodes. System components should not compete with application pods. Nodes being drained should stop accepting new work. Taints, tolerations, and node affinity give you control over where pods run and where they do not.
A taint is applied to a node and tells the scheduler “do not place pods here unless they explicitly tolerate this taint.” Taints have three parts: a key, a value, and an effect.