DevOps Glossary

Kubernetes PodDisruptionBudget (PDB) is a Kubernetes policy object that controls how many matching pods can be voluntarily evicted at one time, so an application keeps enough replicas running during node drains, cluster upgrades, autoscaling events, or maintenance. A PDB uses a label selector to target pods and sets either minAvailable, such as “keep at least 2 pods running,” or maxUnavailable, such as “allow only 1 pod to be unavailable.” It protects against voluntary disruptions, but it does not stop involuntary failures such as node crashes, hardware issues, or a pod being killed because it exceeded memory limits. PDBs are most useful for replicated workloads managed by Deployments, StatefulSets, or ReplicaSets, especially in production clusters where safe maintenance and Kubernetes infrastructure management need predictable availability.