Implement horizontal auto scaling based on Alibaba Cloud metrics

apiVersion: apps/v1 
kind: Deployment
metadata:
  name: nginx-deployment-basic
  labels:
    app: nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9 
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: nginx
  namespace: default
spec:
  ports:
    - port: 80
      protocol: TCP
      targetPort: 80
  selector:
    app: nginx
  type: ClusterIP

1. In the left-side navigation pane of the ACK console, choose Marketplace > Orchestration Templates.
2. On the Templates page, select HPA and click Create Application to deploy the following YAML file.

   apiVersion: autoscaling/v2beta2
   kind: HorizontalPodAutoscaler
   metadata:
     name: ingress-hpa
   spec:
     scaleTargetRef:
       apiVersion: apps/v1
       kind: Deployment
       name: nginx-deployment-basic
     minReplicas: 2
     maxReplicas: 10
     metrics:
       - type: External
         external:
           metric:
             name: sls_ingress_qps
             selector:
               matchLabels:
                 sls.project: "***"
                 sls.logstore: "nginx-ingress"
                 sls.ingress.route: "default-nginx-80"
           target:
             type: AverageValue
             averageValue: 10
       - type: External
         external:
           metric:
             name: sls_ingress_latency_p9999
             selector:
               matchLabels:
                 # default ingress log project is k8s-log-clusterId
                 sls.project: "***"
                 # default ingress logstre is nginx-ingress
                 sls.logstore: "nginx-ingress"
                 # namespace-svc-port
                 sls.ingress.route: "default-nginx-80"
                 # sls vpc endpoint, default true
                 # sls.internal.endpoint:ture
           target:
             type: Value
             # sls_ingress_latency_p9999 > 10ms
             value: 10

   The following table lists the HPA parameters that are used in the preceding example.

   Parameter	Description
   sls.ingress.route	-
   sls.logstore	-
   sls.project	-
   sls.internal.endpoint	Specifies whether to access Log Service over an internal network or the Internet. Default value: true. If you set the value to true, you can access Log Service over an internal network. If you set the value to false, you can access Log Service over the Internet.

   Note

   In the preceding example, the HPA implements auto scaling based on metrics sls_ingress_qps and sls_ingress_latency_p9999. In the target section, each metric has a different type value.

   • The type of the metric sls_ingress_qps is set to AverageValue. This indicates that the query rate of the ingress is an average value by dividing the number of pods.
   • The type of the metric sls_ingress_latency_p9999 is set to Value. This indicates the maximum latency for the fastest 99.99% of all requests.

   The preceding values of type are commonly used in the HPA configurations.
3. On the Templates - HPA page, click Create.

#! /bin/bash
##Use Apache Bench to send requests to the service that can be accessed through an ingress. The test lasts 300 seconds and 10 concurrent requests are sent per second.
ab -t 300 -c 10 <The domain of the ingress>

1. In the left-side navigation pane of the ACK console, click Clusters. On the Clusters page, find the cluster that you want to manage and choose More > Open Cloud Shell in the Actions column.
2. Run the kubectl get hpa ingress-hpa command to check the scaling status.

   If the value of REPLICAS is the same as that of MAXPODS, the scaling is completed.