This topic is weighed 10% on exam

Troubleshoot application failure.

Troubleshoot control plane failure.

Troubleshoot worker node failure.

Troubleshoot networking.

  • Troubleshooting services
    1. Make sure you’re connecting to the service’s cluster IP from within the cluster, not from the outside.
    2. Don’t bother pinging the service IP to figure out if the service is accessible (remember, the service’s cluster IP is a virtual IP and pinging it will never work).
    3. If you’ve defined a readiness probe, make sure it’s succeeding; otherwise the pod won’t be part of the service.
    4. To confirm that a pod is part of the service, examine the corresponding Endpoints object with kubectl get endpoints.
    5. If you’re trying to access the service through its FQDN or a part of it (for example, myservice.mynamespace.svc.cluster.local or myservice.mynamespace) and it doesn’t work, see if you can access it using its cluster IP instead of the FQDN.
    6. Check whether you’re connecting to the port exposed by the service and not the target port.
    7. Try connecting to the pod IP directly to confirm your pod is accepting connections on the correct port.
    8. If you can’t even access your app through the pod’s IP, make sure your app isn’t only binding to localhost.