Kubernetes 다중 스케줄러(Multiple Scheduler) 개념과 설정

1. 개념

• kube-Scheduler를 활용하지 않고 개별 스케줄러를 생성하여 리소스 배포 시 사용 가능
• 또한 1개가 아닌 여러개의 스케줄러를 동시에 사용 가능

---

2. 다중 스케줄러 생성

• 쿠버네티스 공식 문서를 참고해 yaml 파일 생성

apiVersion: v1
kind: ServiceAccount
metadata:
  name: zero-scheduler
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: zero-scheduler-as-kube-scheduler
subjects:
- kind: ServiceAccount
  name: zero-scheduler
  namespace: kube-system
roleRef:
  kind: ClusterRole
  name: system:kube-scheduler
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: zero-scheduler-as-volume-scheduler
subjects:
- kind: ServiceAccount
  name: zero-scheduler
  namespace: kube-system
roleRef:
  kind: ClusterRole
  name: system:volume-scheduler
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: zero-scheduler-config
  namespace: kube-system
data:
  zero-scheduler-config.yaml: |
    apiVersion: kubescheduler.config.k8s.io/v1beta2
    kind: KubeSchedulerConfiguration
    profiles:
      - schedulerName: zero-scheduler
    leaderElection:
      leaderElect: false    
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    component: scheduler
    tier: control-plane
  name: zero-scheduler
  namespace: kube-system
spec:
  selector:
    matchLabels:
      component: scheduler
      tier: control-plane
  replicas: 1
  template:
    metadata:
      labels:
        component: scheduler
        tier: control-plane
        version: second
    spec:
      serviceAccountName: zero-scheduler
      containers:
      - command:
        - /usr/local/bin/kube-scheduler
        - --config=/etc/kubernetes/zero-scheduler/zero-scheduler-config.yaml
        image: <set-your-scheduler-image or k8s.gcr.io/kube-scheduler:v1.24.0>
        livenessProbe:
          httpGet:
            path: /healthz
            port: 10259
            scheme: HTTPS
          initialDelaySeconds: 15
        name: kube-second-scheduler
        readinessProbe:
          httpGet:
            path: /healthz
            port: 10259
            scheme: HTTPS
        resources:
          requests:
            cpu: '0.1'
        securityContext:
          privileged: false
        volumeMounts:
          - name: config-volume
            mountPath: /etc/kubernetes/zero-scheduler
      hostNetwork: false
      hostPID: false
      volumes:
        - name: config-volume
          configMap:
            name: zero-scheduler-config

---

3. 스케줄러 생성 확인

• 스케줄러 생성 확인

---

4. 다중 스케줄러 적용

• schedulerName에 생성한 스케줄러 이름 명시 후 배포

apiVersion: v1
kind: Pod
metadata:
  labels:
    run: nginx
  name: nginx
spec:
  containers:
  - image: nginx
    name: nginx
  schedulerName: zero-scheduler

---

5. 배포 시 다중 스케줄러 적용 확인

• 파드 정상 배포 확인

• 다중 스케줄러 적용 확인(kubectl get events -o wide)