303 — Resource Limits and Autoscaling

Advanced

Master resource management with requests and limits, implement horizontal and vertical pod autoscaling for efficient cluster utilization.

Learning Objectives

Configure CPU and memory requests and limits

Implement Horizontal Pod Autoscaler (HPA)

Understand resource quotas and limit ranges

Monitor resource usage

Step 1

Create pod with resource requests and limits

Define minimum and maximum resources for containers.

Commands to Run

cat > pod-resources.yaml << 'EOF'
apiVersion: v1
kind: Pod
metadata:
  name: resource-pod
spec:
  containers:
  - name: app
    image: nginx:alpine
    resources:
      requests:
        memory: "64Mi"
        cpu: "250m"
      limits:
        memory: "128Mi"
        cpu: "500m"
EOF

kubectl apply -f pod-resources.yaml

kubectl describe pod resource-pod

What This Does

Requests guarantee minimum resources.

Limits cap maximum usage.

Scheduler uses requests for placement decisions.

Expected Outcome

Pod created with resource constraints.

Description shows requests and limits.

Pro Tips

1
Requests: minimum guaranteed resources
2
Limits: maximum allowed resources
3
CPU: millicores (1000m = 1 CPU core)
4
Memory: Mi (mebibytes) or Gi (gibibytes)
5
Pod evicted if exceeds memory limit
6
CPU throttled if exceeds CPU limit

Common Mistakes to Avoid

⚠️Not setting limits (pods can consume all node resources)
⚠️Setting limits too low (causing OOMKilled errors)
⚠️Setting requests higher than limits (invalid configuration)

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