Kubernetes CrashLoopBackOff Production Recovery

Context

A production Kubernetes cluster running in Azure (AKS). A Zabbix alert reported pods of an application component down. CrashLoopBackOff was active.

Problem

The component was failing fast and restarting in a loop. Application traffic to its responsibilities was degraded. The cause needed to be isolated quickly with the cluster still under load.

My role

First responder on the alert: triage, diagnosis, and recovery in the live cluster.

Technical actions

1. [01] Acknowledged the Zabbix alert and pulled pod state, events and recent logs.
2. [02] Inspected restart counts, exit codes and the most recent container output to isolate the failing path.
3. [03] Cross-checked configuration and dependencies the component relied on at start-up.
4. [04] Drove the component back to a healthy ready state and confirmed steady-state behaviour after recovery.
5. [05] Captured the diagnostic path so the next on-call would not need to re-discover it.

Operational impact

Component restored to a healthy ready state. Diagnostic path documented for future incidents of the same shape.

What this demonstrates

• Live-cluster Kubernetes troubleshooting under alert pressure.
• Reading pod state, events and logs as a first language.
• Closing the loop from alert to recovery to runbook improvement.