Unable to drain AKS node due to pdb with 50% maxUnavailable

Question

What is the problem with this config.

Whenever I run kubectl drain <node> this error is coming: "Cannot evict pod as it would violate the pod's disruption budget"

How to resolve it.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment2
spec:
  replicas: 20
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
  selector:
    matchLabels:
      app: nginx2
  template:
    metadata:
      labels:
        app: nginx2
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        ports:
        - containerPort: 80
---
apiVersion: policy/v1
kind: PodDisruptionBudget
metadata:
  name: pdb-nginx2
spec:
  maxUnavailable: 50%
  selector:
    matchLabels:
      app: nginx2

Answer 1

Hello Tanul,

Thanks for your question.

Your deployment is maxUnavailable: 25% and PodDisruptionBudget is maxUnavailable: 50 percent (which means that at most 50% of the pods can be unavailable at any given time). With 20 replicas, 50% maxUnavailable means 10 pods can be unavailable.

Try this:

apiVersion: policy/v1
kind: PodDisruptionBudget
metadata:
  name: pdb-nginx2
spec:
  maxUnavailable: 75%
  selector:
    matchLabels:
      app: nginx2

You can mark it 'Accept Answer' and 'Upvote' if this helped you

Regards,

Abiola