How Kubernetes Finalizers Cause Silent Resource Leaks

Episode notes

In this episode of DevOps Daily with Fexingo, Lucas and Luna dive into one of Kubernetes' most overlooked failure modes: finalizers that block resource deletion indefinitely. They walk through a real incident at a mid-sized e-commerce company where leftover finalizers on PersistentVolumeClaims caused a storage quota blowout over three months, racking up $12,000 in orphaned cloud disk costs. Lucas explains how finalizers work under the hood — as pre-deletion hooks that can fail silently — and why common patterns like finalizer-based cleanup for custom resources often leave dangling references. Luna shares a practical debugging technique using kubectl and jq to find stuck resources. They also discuss mitigation strategies: setting deletion timestamps, monitoring finalizer counts, and avoiding finalizers for stateless cleanup. A sharp, actionable episode for anyone managing Kubernetes in production.