What is the purpose of the 'liveness probe' in a Kubernetes pod?

The purpose of a liveness probe in a Kubernetes pod is to check if the application running inside the pod is still alive and functioning correctly. If the liveness probe fails, it indicates that the application has encountered a problem that it cannot recover from on its own, leading the kubelet to restart the pod. This automatic restart of the pod helps in maintaining high availability and ensuring that the application is running properly.

In contrast, readiness probes serve a different role by determining if a pod is ready to accept traffic. While it is crucial for the stability of applications, the readiness status doesn’t directly influence whether the pod should be restarted or not. The other options, such as monitoring resource usage or managing network routing, fall outside the scope of what liveness probes are designed to accomplish, further emphasizing the correctness of the choice related to pod restarts.