CKAD Application Observability and Maintenance Practice Test 11 — 15 Questions

Question 1

A pod is running but not responding to traffic. You suspect the application inside the container is unhealthy but the pod is still marked as 'Running'. Which probe should be configured to remove the pod from the service's endpoints automatically?

Accepted Answer

Readiness probe. A readiness probe determines if a container is ready to serve traffic. If it fails, the pod is removed from service endpoints.

Answer

Resource limits

Answer

Startup probe

Answer

Liveness probe

Question 2

You want to view the logs of a pod named 'web-pod' that has two containers: 'nginx' and 'sidecar'. Which command correctly streams the logs from the 'nginx' container?

Accepted Answer

kubectl logs web-pod -c nginx. When a pod has multiple containers, you must specify the container name with -c flag.

Answer

kubectl logs -c nginx web-pod

Answer

kubectl logs web-pod nginx

Answer

kubectl logs web-pod --container nginx

Question 3

You have a pod 'app-pod' that keeps restarting. You want to see the logs from the previous (crashed) container instance. Which command should you use?

Accepted Answer

kubectl logs app-pod --previous. The --previous flag shows logs from the previous instance of a container.

Answer

kubectl logs app-pod -p

Answer

kubectl logs app-pod -f

Answer

kubectl describe pod app-pod

Question 4

A developer reports that a pod named 'api-pod' is restarted repeatedly. You run 'kubectl get events --field-selector involvedObject.name=api-pod' and see multiple events with reason 'BackOff' and message 'Back-off restarting failed container'. Which probe failure is MOST likely causing this?

Accepted Answer

Liveness probe failure. BackOff restarting failed container indicates that the container exited and is being restarted by the restart policy. This is commonly caused by a failing liveness probe that kills the container, or the container itself exits. The liveness probe is designed to restart unhealthy containers.

Answer

Resource quota exceeded

Answer

Readiness probe failure

Answer

Startup probe failure

Question 5

You are writing a Deployment manifest for a container that takes up to 60 seconds to become ready. You want to ensure the liveness probe does not interfere during this startup period. What should you configure?

Accepted Answer

Configure a startup probe with a sufficient failureThreshold and period. A startup probe is designed for slow-starting containers. It runs at startup and only after it succeeds does the liveness probe take over.

Answer

Set liveness probe failureThreshold to a high number

Answer

Set readiness probe initialDelaySeconds to 60

Answer

Set liveness probe initialDelaySeconds to 60

Question 6

A pod is stuck in 'Pending' state. You run 'kubectl describe pod pending-pod' and see the following condition: 'Status: False, Type: PodScheduled, Reason: Unschedulable, Message: 0/4 nodes are available: 1 node(s) had taint {node.kubernetes.io/disk-pressure: }, 1 node(s) had taint {node.kubernetes.io/memory-pressure: }, 2 node(s) didn't match Pod's node affinity/selector.' What is the most specific reason the pod cannot be scheduled?

Accepted Answer

Node taints and/or affinity rules prevent scheduling. The message indicates multiple issues: taints and node affinity. The pod cannot be scheduled due to taints not being tolerated AND node affinity not matching.

Answer

Container image pull failure

Answer

Pod is in CrashLoopBackOff

Answer

Insufficient CPU resources

Question 7

You need to check the CPU and memory usage of a pod named 'monitored-pod' in the 'default' namespace. Which command should you run?

Accepted Answer

kubectl top pod monitored-pod. The kubectl top pod command shows resource usage for pods.

Answer

kubectl get pod monitored-pod -o wide

Answer

kubectl describe pod monitored-pod

Answer

kubectl logs monitored-pod

Question 8

You want to run a command inside an existing container 'app-container' in pod 'my-pod'. The pod has only one container. Which command enters an interactive shell?

Accepted Answer

kubectl exec -it my-pod -- /bin/sh. kubectl exec -it podname -- /bin/sh opens an interactive shell inside the container.

Answer

kubectl exec my-pod -c app-container /bin/sh

Answer

kubectl run -it my-pod --image=busybox

Answer

kubectl attach my-pod

Question 9

You want to debug a pod that has no shell or debugging tools installed. Which feature allows you to temporarily add a sidecar container with debugging tools to a running pod?

Accepted Answer

kubectl debug -it my-pod --image=busybox --target=my-container. Ephemeral containers are designed for debugging running pods without restarting them.

Answer

kubectl exec -it my-pod -- /bin/bash

Answer

kubectl cp /tmp/debug-tool my-pod:/tmp/

Answer

kubectl port-forward my-pod 8080:80

Question 10

You need to configure a container to shut down gracefully when it receives a SIGTERM signal, with a timeout of 30 seconds before force kill. Which field in the Pod spec should you set?

Accepted Answer

terminationGracePeriodSeconds. terminationGracePeriodSeconds sets the time Kubernetes waits for a pod to shut down gracefully after sending SIGTERM.

Answer

activeDeadlineSeconds

Answer

livenessProbe.periodSeconds

Answer

restartPolicy

Question 11

You have a Deployment called 'web-deploy' with 3 replicas. One of the pods is not receiving traffic, but it shows 'Running' and passes its liveness probe. The readiness probe is configured as a TCP socket check on port 8080. You verify that the application is listening on port 8080. What is a likely reason the pod is not receiving traffic?

Accepted Answer

The readiness probe is succeeding even though the application is not truly ready, because TCP check only verifies the port is open. If the readiness probe passes, the pod should be in service endpoints. But if the probe passes incorrectly (e.g., TCP socket check succeeds even if app is not fully ready), the pod might be marked ready but not actually serve traffic. However, the question says readiness probe is TCP on 8080 and app listens on 8080, so it should work. Another possibility: the pod might have a misconfigured service selector or the pod's labels do not match. But from the options, the most plausible is that the readiness probe is not properly checking application health.

Answer

The service is configured to use a different port

Answer

The pod's node is cordoned

Answer

The liveness probe is failing and restarting the container

Question 12

You run 'kubectl get pods -o wide' and see that a pod 'worker-pod' is in 'Completed' state with 'Restart Count: 5'. The pod's restart policy is 'OnFailure'. What is the most likely reason the pod has restarted 5 times?

Accepted Answer

The container exited with non-zero exit code multiple times before succeeding. A pod with restartPolicy: OnFailure will restart the container if it exits with a non-zero exit code. The pod is Completed, meaning the container exited with 0 eventually, but previous runs exited with non-zero.

Answer

The liveness probe failed and restarted the container

Answer

The pod's node was rebooted

Answer

The pod was evicted due to node pressure

Question 13

You deploy a pod with the following specification:

apiVersion: v1
kind: Pod
metadata:
  name: probe-pod
spec:
  containers:
  - name: app
    image: nginx
    livenessProbe:
      httpGet:
        path: /healthz
        port: 8080
      initialDelaySeconds: 5
      periodSeconds: 10
      failureThreshold: 3

The application listens on port 80, not 8080. What will happen to the pod?

Accepted Answer

The container will be restarted repeatedly due to liveness probe failure. The liveness probe will fail because it checks port 8080 but the app listens on 80. After failureThreshold failures (3 * periodSeconds = 30 seconds after initial delay), the container will be restarted.

Answer

The pod will be terminated and not restarted

Answer

The pod will start and run normally

Answer

The pod will be stuck in 'Pending' state

Question 14

Which kubectl command shows detailed information about a pod, including events, labels, and container state?

Accepted Answer

kubectl describe pod my-pod. kubectl describe pod provides detailed information about a pod.

Answer

kubectl logs my-pod

Answer

kubectl get pod my-pod -o yaml

Answer

kubectl top pod my-pod

Question 15

You want to view the events related to a specific pod named 'my-pod' in the 'default' namespace. Which command filters events to show only those pertaining to this pod?

Accepted Answer

kubectl get events --field-selector involvedObject.name=my-pod. kubectl get events --field-selector involvedObject.name=my-pod shows events for that pod.

Answer

kubectl describe pod my-pod

Answer

kubectl get events | grep my-pod

Answer

kubectl logs my-pod