chapter eight

8 Troubleshooting Kubernetes

 

This chapter covers

  • Monitoring and viewing logs
  • Identifying high CPU or RAM usage
  • Resolving common cluster problems
  • Analyzing network traffic to identify communication concerns

Troubleshooting is the biggest topic (30%) on the Certified Kubernetes Administrator (CKA) exam, so we cover it in great detail in this chapter. Troubleshooting means fixing problems with applications, control plane components, worker nodes, and the underlying network. When running application pods in Kubernetes, problems will arise, such as concerns with pods, Services, and Deployments.

The Troubleshooting domain

This chapter covers the Troubleshooting domain of the CKA curriculum, which comprises 30% of the questions on the exam. This domain covers the techniques we use to discover and fix problems inside our Kubernetes cluster, including viewing the logs, capturing cluster events, networking problems, and application monitoring. It encompasses the following competencies.

Competency
Chapter section
Monitor cluster and application resource usage
8.1
Manage and evaluate container output streams
8.1
Troubleshoot cluster components
8.1, 8.2, 8.3
Troubleshoot clusters and nodes
8.2
Troubleshoot Services and networking
8.3

8.1 Understanding application logs

8.1.1 Container log detail

8.1.2 Troubleshooting from inside the container

8.2 Cluster component failure

8.2.1 Troubleshooting cluster events

8.2.2 Worker node failure

8.2.3 Did you specify the right host or port?

8.2.4 Troubleshooting kubeconfig

8.2.5 Multiple errors: Where to start?

8.3 Network troubleshooting

8.3.1 Troubleshooting the config

8.3.2 Troubleshooting Services

8.3.3 Troubleshooting cluster-wide communications

Summary