Vertical Pod Autoscaling (VPA) is a feature in Kubernetes that automatically adjusts the CPU and memory requests and limits for your pods based on their actual usage. This ensures that your applications have the resources they need to run efficiently without over-provisioning.
Key Concepts
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Resource Requests and Limits:
- Requests: The amount of CPU and memory guaranteed to a container.
- Limits: The maximum amount of CPU and memory a container can use.
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Vertical Pod Autoscaler (VPA):
- A Kubernetes component that monitors the resource usage of pods and adjusts their resource requests and limits accordingly.
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VPA Modes:
- Off: VPA is not active.
- Auto: VPA automatically updates the resource requests and limits.
- Recreate: VPA updates the resource requests and limits by recreating the pods.
- Initial: VPA sets the initial resource requests and limits when the pod is created.
Setting Up Vertical Pod Autoscaling
Prerequisites
- A running Kubernetes cluster.
kubectl
command-line tool configured to communicate with your cluster.
Installing the Vertical Pod Autoscaler
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Clone the VPA repository:
git clone https://github.com/kubernetes/autoscaler.git cd autoscaler/vertical-pod-autoscaler/
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Deploy the VPA components:
kubectl apply -f vertical-pod-autoscaler/deploy/recommender.yaml kubectl apply -f vertical-pod-autoscaler/deploy/updater.yaml kubectl apply -f vertical-pod-autoscaler/deploy/admission-controller.yaml
Configuring Vertical Pod Autoscaler
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Create a VPA object:
apiVersion: autoscaling.k8s.io/v1 kind: VerticalPodAutoscaler metadata: name: my-vpa spec: targetRef: apiVersion: "apps/v1" kind: Deployment name: my-deployment updatePolicy: updateMode: "Auto"
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Apply the VPA configuration:
kubectl apply -f my-vpa.yaml
Example Deployment with VPA
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Create a sample deployment:
apiVersion: apps/v1 kind: Deployment metadata: name: my-deployment spec: replicas: 2 selector: matchLabels: app: my-app template: metadata: labels: app: my-app spec: containers: - name: my-container image: nginx resources: requests: cpu: "100m" memory: "128Mi" limits: cpu: "200m" memory: "256Mi"
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Apply the deployment:
kubectl apply -f my-deployment.yaml
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Apply the VPA configuration:
kubectl apply -f my-vpa.yaml
Monitoring and Managing VPA
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Check VPA recommendations:
kubectl describe vpa my-vpa
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View updated resource requests and limits:
kubectl get pods -o=jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[*].resources}{"\n"}{end}'
Practical Exercise
Exercise: Implement Vertical Pod Autoscaling
- Create a deployment for a sample application.
- Configure and apply a VPA object for the deployment.
- Monitor the resource adjustments made by VPA.
Solution
-
Create a deployment:
apiVersion: apps/v1 kind: Deployment metadata: name: sample-deployment spec: replicas: 2 selector: matchLabels: app: sample-app template: metadata: labels: app: sample-app spec: containers: - name: sample-container image: nginx resources: requests: cpu: "100m" memory: "128Mi" limits: cpu: "200m" memory: "256Mi"
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Apply the deployment:
kubectl apply -f sample-deployment.yaml
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Create a VPA configuration:
apiVersion: autoscaling.k8s.io/v1 kind: VerticalPodAutoscaler metadata: name: sample-vpa spec: targetRef: apiVersion: "apps/v1" kind: Deployment name: sample-deployment updatePolicy: updateMode: "Auto"
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Apply the VPA configuration:
kubectl apply -f sample-vpa.yaml
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Monitor the VPA recommendations:
kubectl describe vpa sample-vpa
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Check the updated resource requests and limits:
kubectl get pods -o=jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[*].resources}{"\n"}{end}'
Common Mistakes and Tips
- Incorrect VPA mode: Ensure the
updateMode
is set correctly based on your needs (e.g.,Auto
for automatic updates). - Resource limits too high/low: Monitor the resource usage and adjust the initial requests and limits accordingly.
- Not monitoring VPA recommendations: Regularly check VPA recommendations to ensure your pods are getting the right resources.
Conclusion
Vertical Pod Autoscaling is a powerful feature in Kubernetes that helps optimize resource usage by automatically adjusting the CPU and memory requests and limits for your pods. By setting up and configuring VPA, you can ensure that your applications run efficiently without over-provisioning resources. In the next section, we will explore Cluster Autoscaling, which focuses on scaling the entire cluster based on resource demands.
Kubernetes Course
Module 1: Introduction to Kubernetes
- What is Kubernetes?
- Kubernetes Architecture
- Key Concepts and Terminology
- Setting Up a Kubernetes Cluster
- Kubernetes CLI (kubectl)
Module 2: Core Kubernetes Components
Module 3: Configuration and Secrets Management
Module 4: Networking in Kubernetes
Module 5: Storage in Kubernetes
Module 6: Advanced Kubernetes Concepts
Module 7: Monitoring and Logging
- Monitoring with Prometheus
- Logging with Elasticsearch, Fluentd, and Kibana (EFK)
- Health Checks and Probes
- Metrics Server
Module 8: Security in Kubernetes
Module 9: Scaling and Performance
Module 10: Kubernetes Ecosystem and Tools
Module 11: Case Studies and Real-World Applications
- Deploying a Web Application
- CI/CD with Kubernetes
- Running Stateful Applications
- Multi-Cluster Management