Vertical Pod Autoscaler concept in Kubernetes - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Vertical Pod Autoscaler resource for a deployment named 'web-app'.

Kubernetes

apiVersion: autoscaling.k8s.io/v1
kind: VerticalPodAutoscaler
metadata:
  name: web-app-vpa
spec:
  targetRef:
    kind: Deployment
    name: [1]

Drag options to blanks, or click blank then click option'

Aweb-app

Bdatabase

Ccache

Dfrontend

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different deployment name that does not exist.

Confusing the kind field with the deployment name.

The Vertical Pod Autoscaler targets the deployment named 'web-app' to adjust its resource requests automatically.

2fill in blank

medium

Complete the code to set the update policy of the Vertical Pod Autoscaler to 'Auto'.

Kubernetes

spec:
  updatePolicy:
    updateMode: [1]

Drag options to blanks, or click blank then click option'

AOff

BInitial

CAuto

DManual

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'Off' disables updates.

Using 'Manual' requires manual approval for updates.

Setting updateMode to 'Auto' allows the Vertical Pod Autoscaler to automatically update pod resource requests.

3fill in blank

hard

Fix the error in the resource specification by completing the missing field for resource policy to limit CPU max usage.

Kubernetes

spec:
  resourcePolicy:
    containerPolicies:
    - containerName: '*'
      maxAllowed:
        cpu: [1]

Drag options to blanks, or click blank then click option'

A2Gi

B1Gi

C500m

D1000m

Attempts:

3 left

💡 Hint

Common Mistakes

Using memory units like 'Gi' for CPU limits.

Setting too low CPU limits causing pod failures.

The maxAllowed CPU value should be in millicores, so '1000m' means 1 CPU core max allowed.

4fill in blank

hard

Fill both blanks to define a VPA that targets a StatefulSet named 'db-statefulset' and sets the update mode to 'Initial'.

Kubernetes

spec:
  targetRef:
    kind: [1]
    name: [2]
  updatePolicy:
    updateMode: Initial

Drag options to blanks, or click blank then click option'

AStatefulSet

BDeployment

Cdb-statefulset

Dweb-app

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing Deployment kind with StatefulSet name.

Using wrong updateMode for the scenario.

The VPA targets the StatefulSet named 'db-statefulset' and updateMode 'Initial' applies recommendations only on pod creation.

5fill in blank

hard

Fill all three blanks to create a VPA spec that targets a DaemonSet named 'log-agent', sets update mode to 'Off', and limits memory max allowed to 512Mi.

Kubernetes

spec:
  targetRef:
    kind: [1]
    name: [2]
  updatePolicy:
    updateMode: [3]
  resourcePolicy:
    containerPolicies:
    - containerName: '*'
      maxAllowed:
        memory: 512Mi

Drag options to blanks, or click blank then click option'

ADaemonSet

Blog-agent

COff

DDeployment

Attempts:

3 left

💡 Hint

Common Mistakes

Using Deployment kind instead of DaemonSet.

Setting updateMode to 'Auto' when 'Off' is required.

The VPA targets the DaemonSet 'log-agent', disables automatic updates with 'Off', and limits memory to 512Mi.

Practice

1. What is the main purpose of the Vertical Pod Autoscaler in Kubernetes?

easy

A. Schedule pods to specific nodes manually

B. Scale the number of pod replicas up or down

C. Manage network policies between pods

D. Automatically adjust CPU and memory requests for pods based on usage

Solution

1. Step 1: Understand VPA's role

   The Vertical Pod Autoscaler changes resource requests (CPU, memory) for pods automatically based on their usage.

2. Step 2: Differentiate from other autoscalers

   Unlike Horizontal Pod Autoscaler, which changes pod count, VPA adjusts resource limits inside pods.

3. Final Answer:

   Automatically adjust CPU and memory requests for pods based on usage -> Option D

4. Quick Check:

   VPA adjusts resources, not pod count [OK]

Hint: VPA changes pod resources, not pod numbers [OK]

Common Mistakes:

• Confusing VPA with Horizontal Pod Autoscaler
• Thinking VPA manages pod replicas
• Assuming VPA controls networking

2. Which of the following is the correct YAML snippet to create a Vertical Pod Autoscaler targeting a deployment named my-app?

easy

A. apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
name: my-app-hpa
spec:
scaleTargetRef:
apiVersion: apps/v1
kind: Deployment
name: my-app

B. apiVersion: autoscaling.k8s.io/v1
kind: VerticalPodAutoscaler
metadata:
name: my-app-vpa
spec:
targetRef:
apiVersion: apps/v1
kind: Deployment
name: my-app

C. apiVersion: v1
kind: Pod
metadata:
name: my-app-pod
spec:
containers:
- name: my-app
image: my-app-image

D. apiVersion: autoscaling.k8s.io/v2
kind: VerticalPodAutoscaler
metadata:
name: my-app-vpa
spec:
target:
apiVersion: apps/v1
kind: Deployment
name: my-app

Solution

1. Step 1: Check apiVersion and kind

   Correct VPA uses apiVersion: autoscaling.k8s.io/v1 and kind: VerticalPodAutoscaler.

2. Step 2: Verify targetRef structure

   The targetRef field must specify the deployment with apiVersion, kind, and name correctly.

3. Final Answer:

   YAML with apiVersion autoscaling.k8s.io/v1, kind VerticalPodAutoscaler, and targetRef for my-app deployment -> Option B

4. Quick Check:

   VPA YAML uses targetRef, autoscaling.k8s.io/v1 [OK]

Hint: VPA uses targetRef, not scaleTargetRef [OK]

Common Mistakes:

• Using HorizontalPodAutoscaler instead of VerticalPodAutoscaler
• Wrong apiVersion like autoscaling/v1
• Incorrect field name target instead of targetRef

3. Given this VPA configuration snippet, what will happen when the pod's CPU usage increases beyond the current request?

apiVersion: autoscaling.k8s.io/v1
kind: VerticalPodAutoscaler
metadata:
  name: example-vpa
spec:
  targetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: example-app
  updatePolicy:
    updateMode: "Auto"

medium

A. The VPA will automatically update the pod's CPU requests to match usage

B. The pod replicas will increase to handle the load

C. The pod will restart immediately to apply new resources

D. Nothing happens until manual intervention

Solution

1. Step 1: Understand updateMode Auto

   When updateMode is Auto, VPA automatically adjusts resource requests without manual steps.

2. Step 2: Effect on pod resources

   VPA changes CPU and memory requests to match observed usage, improving stability and efficiency.

3. Final Answer:

   The VPA will automatically update the pod's CPU requests to match usage -> Option A

4. Quick Check:

   updateMode Auto means automatic resource adjustment [OK]

Hint: Auto updateMode means VPA adjusts resources automatically [OK]

Common Mistakes:

• Confusing VPA with Horizontal Pod Autoscaler scaling pods
• Thinking pods restart immediately on resource change
• Assuming manual approval is needed with Auto mode

4. You applied a Vertical Pod Autoscaler with updateMode: Auto, but pod resource requests did not change after high CPU usage. What is a likely cause?

medium

A. The Horizontal Pod Autoscaler is overriding VPA settings

B. The pod replicas are too few to trigger scaling

C. The VPA targetRef is incorrect or does not match the pods

D. The pod image version is outdated

Solution

1. Step 1: Check VPA targetRef correctness

   If targetRef does not correctly point to the pods or deployment, VPA cannot adjust resources.

2. Step 2: Understand VPA scope

   VPA only adjusts resources for pods matching targetRef; replicas count or pod image do not affect resource updates directly.

3. Final Answer:

   The VPA targetRef is incorrect or does not match the pods -> Option C

4. Quick Check:

   Incorrect targetRef means no resource updates [OK]

Hint: Verify targetRef matches pods exactly [OK]

Common Mistakes:

• Blaming pod replicas count for resource update failure
• Assuming HPA conflicts with VPA resource updates
• Thinking pod image version affects VPA behavior

5. You want to use Vertical Pod Autoscaler but avoid pod restarts during resource updates. Which updateMode should you choose and why?

hard

A. "Initial" to set resources only at pod creation without restarts later

B. "Auto" to update resources and restart pods automatically

C. "Off" to disable updates and avoid restarts

D. "Manual" to require manual approval before updates

Solution

1. Step 1: Understand updateMode options

   "Off" disables updates, "Auto" updates and restarts pods, "Initial" sets resources only at pod start, "Manual" requires manual approval.

2. Step 2: Choose mode to avoid restarts

   "Initial" mode applies resource recommendations only when pods start, so no restarts happen later.

3. Final Answer:

   "Initial" to set resources only at pod creation without restarts later -> Option A

4. Quick Check:

   Initial mode avoids restarts by updating only at pod start [OK]

Hint: Use Initial mode to avoid pod restarts on resource changes [OK]

Common Mistakes:

• Choosing Off disables VPA completely
• Assuming Manual mode avoids restarts automatically
• Confusing Auto mode with no restarts