EKS nodes speed workloads launch time use placeholde free one node

calendar Feb 20, 2023 ·  · EKS kubernetes  ·
: linkedin copy

Create eks node group label and taint

 1labels = {
 2        "node-group" : "spotInstances"
 3}
 4taints = [
 5        {
 6          effect = "NO_SCHEDULE"
 7          key    = "devops"
 8          value  = "forceSchedule"
 9        }
10]

Create priorityClass one to placeholder other one to nornal schedule

 1apiVersion: scheduling.k8s.io/v1
 2kind: PriorityClass
 3metadata:
 4  name: placeholder
 5value: 0
 6preemptionPolicy: Never
 7globalDefault: false
 8description: 'placeholder'
 9---
10apiVersion: scheduling.k8s.io/v1
11kind: PriorityClass
12metadata:
13  name: normal
14value: 1
15preemptionPolicy: Never
16globalDefault: true              # default
17description: 'normal'

Use placeholde deployment

 1apiVersion: apps/v1
 2kind: Deployment
 3metadata:
 4  name: placeholder
 5spec:
 6  replicas: 1 # how many placeholder node should launch
 7  selector:
 8    matchLabels:
 9      app: placeholder
10  template:
11    metadata:
12      labels:
13        app: placeholder
14    spec:
15      terminationGracePeriodSeconds: 0        # important
16      priorityClassName: placeholder          # important
17      containers:
18      - image: nginx:1.23.1-alpine
19        name: placeholder
20        resources:
21          requests:
22            cpu: 3500m # this will use almost cpu
23      affinity:
24        nodeAffinity:
25          requiredDuringSchedulingIgnoredDuringExecution:
26            nodeSelectorTerms:
27              - matchExpressions:
28                  - key: node-group
29                    operator: In
30                    values:
31                      - spotInstances
32      tolerations:
33      - key: "devops"
34        operator: "Equal"
35        value: "forceSchedule"
36        effect: "NoSchedule"

Schedule the pod to placeholde node and evict the placholder pod and launch new placehole node

 1apiVersion: v1
 2kind: Pod
 3spec:
 4  affinity: 
 5    priorityClassName: normal
 6    nodeAffinity:    
 7    requiredDuringSchedulingIgnoredDuringExecution:
 8        nodeSelectorTerms:
 9        - matchExpressions:                    
10            - key: node-group
11            operator: In
12            values:
13            - spotInstances
14  tolerations:
15  - key: "devops"
16    operator: "Equal"
17    value: "forceSchedule"
18    effect: "NoSchedule"

Reference