CKA Workloads and Scheduling Practice Test 8 — 15 Questions

Question 1

A CronJob is configured to run every hour. You notice that the job did not run at the scheduled time. What is the most likely reason?

Accepted Answer

The concurrency policy is set to 'Forbid' and a previous job was still running. When a CronJob's concurrency policy is set to 'Forbid', it prevents a new job from starting if the previous job is still running. If the previous job took longer than the scheduled interval (e.g., more than one hour), the next scheduled run will be skipped, causing the job not to run at the expected time. This is a common scenario where a long-running job overlaps with the next scheduled time, and the 'Forbid' policy enforces that only one job instance runs at a time.

Answer

The concurrency policy is set to 'Allow'

Answer

The previous job run succeeded and the CronJob is configured to not rerun after success

Answer

The concurrency policy is set to 'Replace'

Question 2

Which TWO of the following are valid ways to specify resource requests and limits for a container in a pod? (Select 2)

Accepted Answer

spec:
  containers:
  - name: app
    resources:
      requests:
        cpu: "500m"
        memory: "512Mi"
      limits:
        cpu: "1"
        memory: "1Gi". Options C and D are both correct. Option C uses the correct YAML structure with a `resources` block containing both `requests` and `limits`, and specifies CPU as a string (e.g., "500m") and memory as a string (e.g., "512Mi"). Option D is also valid because Kubernetes allows specifying only `limits` without `requests`; the request defaults to the limit if omitted. Both options conform to the Kubernetes API specification for resource management in Pod containers. Options A, B, and E contain invalid syntax: A uses CPU and memory directly under the container without a resources block; B uses the singular `resource` instead of the plural `resources`; E uses invalid units ('millicores' and 'MB').

Answer

spec:
  containers:
  - name: app
    cpu: 0.5
    memory: 512Mi

Answer

spec:
  containers:
  - name: app
    resource:
      request:
        cpu: 1
        memory: 1Gi
      limit:
        cpu: 2
        memory: 2Gi

Answer

spec:
  containers:
  - name: app
    resources:
      requests:
        cpu: "500 millicores"
        memory: "512 MB"

Question 3

A CronJob runs every hour. The job takes 45 minutes to complete. What is the default behavior if the next scheduled time occurs while the previous job is still running?

Accepted Answer

The next job starts immediately, running concurrently. By default, CronJobs in Kubernetes have a concurrencyPolicy of 'Allow'. This means that if a new job is scheduled while a previous job is still running, the new job starts immediately and runs concurrently with the previous one. Option C correctly describes this default behavior. If you want to prevent concurrent executions, you must explicitly set concurrencyPolicy to 'Forbid'.

Answer

The next job is queued and starts after the previous finishes

Answer

The next job is skipped

Answer

The CronJob is suspended

Question 4

A pod with an init container that runs a database migration fails. The init container exits with code 1. What is the pod's status?

Accepted Answer

Init:CrashLoopBackOff. When an init container exits with a non-zero exit code (code 1), Kubernetes considers the init container to have failed. By default, the pod restarts the init container according to the pod's restart policy (which defaults to Always for pods, but init containers always restart on failure regardless of the pod's restart policy). This repeated failure and restart cycle places the pod in the Init:CrashLoopBackOff status, indicating that the init container is crashing in a loop.

Answer

Pending

Answer

Failed

Answer

Running

Question 5

Which command creates a ConfigMap named 'app-config' from a file 'config.properties'?

Accepted Answer

kubectl create configmap app-config --from-file=config.properties. `kubectl create configmap app-config --from-file=config.properties` creates a ConfigMap named 'app-config' using the contents of the specified file. The `--from-file` flag reads the file and stores its entire content as a key-value pair, where the key defaults to the filename (config.properties) and the value is the file's content.

Answer

kubectl create cm app-config --file=config.properties

Answer

kubectl create configmap app-config --from-literal=config.properties

Answer

kubectl create configmap app-config --from-env-file=config.properties

Question 6

Which two statements about HorizontalPodAutoscaler (HPA) are correct?

Accepted Answer

HPA is a namespaced resource. HorizontalPodAutoscaler (HPA) is a namespaced resource in Kubernetes, meaning it exists within a specific namespace and can only target resources (like Deployments or StatefulSets) in that same namespace. This is defined in the Kubernetes API under the `autoscaling/v2` group, where HPA objects are scoped to a namespace, not cluster-wide.

Answer

HPA can only target Deployments

Answer

HPA requires the metrics-server to be installed

Answer

HPA can scale down to zero replicas

Question 7

A Pod is stuck in 'Pending' state. You run 'kubectl describe pod my-pod' and see the event: '0/3 nodes are available: 1 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate, 2 Insufficient cpu.' The pod has resource requests: cpu: 2, memory: 1Gi. The cluster has 3 nodes: one control-plane with taint node-role.kubernetes.io/master:NoSchedule, and two worker nodes each with 1 CPU. What is the most likely cause?

Accepted Answer

The pod requests more CPU than any available node can provide.. The pod requests 2 CPU, but each worker node has only 1 CPU, making them insufficient. The control-plane node has the taint `node-role.kubernetes.io/master:NoSchedule` which the pod does not tolerate, so it is also unavailable. The event explicitly states '2 Insufficient cpu', confirming that the CPU request cannot be satisfied by any node.

Answer

The pod requests more memory than any available node can provide.

Answer

The pod has a higher priority than other pods and is preempting them.

Answer

The control-plane node has insufficient resources.

Question 8

You want to ensure that a pod only runs on nodes that have a GPU. Nodes with GPUs are labeled with 'gpu=true'. Which scheduling constraint should you use?

Accepted Answer

spec.nodeSelector: { gpu: "true" }. `spec.nodeSelector` is the simplest and most direct way to constrain a pod to nodes with a specific label. By setting `gpu: "true"` in the nodeSelector, the scheduler will only place the pod on nodes that have that exact label key-value pair. This is the standard Kubernetes mechanism for node-level selection based on labels.

Answer

spec.nodeName: gpu-node

Answer

spec.affinity.podAffinity.requiredDuringSchedulingIgnoredDuringExecution

Answer

spec.affinity.nodeAffinity.requiredDuringSchedulingIgnoredDuringExecution

Question 9

A Pod has an init container that writes a configuration file, and the main container reads that file. The init container runs successfully, but the main container fails with 'file not found'. What is the most likely cause?

Accepted Answer

The init container wrote the file to a different volume than the one mounted in the main container.. The most likely cause is that the init container wrote the configuration file to a volume that is not shared with the main container. In Kubernetes, init containers and main containers in the same Pod share the same filesystem only if they mount the same Volume. If the init container writes to a volume that is not mounted in the main container, or writes to a different path within the same volume, the main container will not see the file. This is a common misconfiguration when using emptyDir or hostPath volumes.

Answer

The main container restarted and the init container did not rerun.

Answer

The main container's command is incorrect.

Answer

The init container did not complete before the main container started.

Question 10

You have a ResourceQuota in a namespace that sets limits: pods: 10, requests.cpu: 4, requests.memory: 8Gi. You try to create a Pod with requests.cpu: 1, requests.memory: 2Gi, and no limits. The namespace currently has 8 pods using 3 CPUs and 5Gi memory in total requests. What happens?

Accepted Answer

The pod is created successfully.. The ResourceQuota only enforces the total sum of requests across all pods in the namespace. Currently, the namespace has 8 pods using 3 CPUs and 5Gi memory. Adding a pod with requests.cpu: 1 and requests.memory: 2Gi would bring totals to 4 CPUs (3+1) and 7Gi memory (5+2), both within the quota limits of 4 CPUs and 8Gi. The pod does not specify limits, but ResourceQuota does not require limits unless a LimitRange enforces default limits; here, no LimitRange is mentioned, so the pod is allowed.

Answer

The pod is rejected because it exceeds the memory request quota.

Answer

The pod is rejected because it exceeds the CPU request quota.

Answer

The pod is rejected because it does not specify CPU and memory limits.

Question 11

Which TWO statements are correct regarding DaemonSets?

Accepted Answer

DaemonSets are often used for cluster monitoring or logging agents.. DaemonSets are designed to run a copy of a pod on every node (or a subset of nodes based on node selectors), making them ideal for cluster-wide infrastructure services such as monitoring agents (e.g., Prometheus Node Exporter), logging agents (e.g., Fluentd), and network plugins (e.g., Calico). This pattern ensures that each node has the necessary agent running without manual intervention.

Answer

DaemonSets do not support rolling updates.

Answer

DaemonSets can be scaled up and down using kubectl scale.

Answer

DaemonSets use a replica count to determine how many pods to run.

Question 12

Which THREE are valid ways to inject configuration data into a pod?

Accepted Answer

Mount a ConfigMap as a volume.. A ConfigMap can be mounted as a volume in a Pod, allowing files to be created or updated in the container's filesystem with configuration data. This is a standard Kubernetes feature where the ConfigMap's data keys become filenames and values become file contents, and updates to the ConfigMap can be reflected in the mounted volume without restarting the Pod (depending on the mount type).

Answer

Use a Secret as a ConfigMap data source.

Answer

Use 'kubectl inject configmap' to inject data at runtime.

Question 13

You have a Deployment named 'web-app' in the 'default' namespace. You run the following command: kubectl rollout history deployment web-app. The output shows: revision 1, revision 2, revision 3. You want to roll back to revision 1. Which command achieves this?

Accepted Answer

kubectl rollout undo deployment web-app --to-revision=1. `kubectl rollout undo` with the `--to-revision` flag is the proper syntax to roll back a Deployment to a specific revision. The command `kubectl rollout undo deployment web-app --to-revision=1` reverts the Deployment to revision 1, as shown in the rollout history output.

Answer

kubectl rollout undo deployment web-app --revision=1

Answer

kubectl rollback deployment web-app --to-revision=1

Answer

kubectl rollout undo deployment web-app

Question 14

You are debugging a Pod that is in 'Pending' state. The output of 'kubectl describe pod' shows: Events: Type Reason Age From Message ---- ------ ---- ---- ------- Warning FailedScheduling 2m default-scheduler 0/3 nodes are available: 1 Insufficient cpu, 2 node(s) had taint {node-role.kubernetes.io/master: }, that the pod didn't tolerate. What does this indicate?

Accepted Answer

The pod cannot be scheduled due to a combination of insufficient CPU and untolerated taints on different nodes. The event message explicitly states that 0/3 nodes are available due to two distinct issues: one node has insufficient CPU, and two nodes have a taint (node-role.kubernetes.io/master) that the pod does not tolerate. This means no single node satisfies all scheduling requirements, so the pod remains Pending. Option B correctly identifies that the scheduling failure is caused by a combination of resource insufficiency and untolerated taints across different nodes, not a single global problem.

Answer

The pod requires more memory than any node can provide

Answer

All nodes have taints that the pod does not tolerate

Answer

All nodes have insufficient CPU resources for the pod

Question 15

You want to run a batch job that processes a queue and then terminates. The job should be run only once. Which Kubernetes resource should you use?

Accepted Answer

Job. A Kubernetes Job is designed to run a specified number of pods to completion, making it the correct choice for a batch process that runs once and then terminates. Unlike controllers that maintain a desired state (like Deployments or DaemonSets), a Job tracks pod completion and will not restart the pod once it succeeds, perfectly matching the requirement of a single execution.

Answer

CronJob

Answer

DaemonSet

Answer

Deployment