Scale a Deployment Using a Horizontal Pod Autoscaler

You can update a deployment to change the number of replicas as shown below. You may prefer to use an fixed number of replicas as described in Scale a Deployment Using Replicas.

Example Customization

1. Create an overlay structure as described in Customize ESS.

2. Add the customization overlay:

   #kustomization.yaml
   
   ...
   
   resources:
     - ess-ldp-autoscaler.yaml
   

   #ess-ldp-autoscaler.yaml
   # ESS Autoscaling
   
   # This needs a Metrics server to be installed. See:
   # https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/
   # The command to install a metrics server is:
   # `kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/download/v0.3.6/components.yaml`
   
   # When the average CPU load is below 40 percent, the autoscaler tries to reduce the number of instances
   # in the deployment, to a minimum of nine which means it uses more than one machine.
   # When the load is greater than 40 percent, the autoscaler
   # tries to increase the number of instances in the deployment, up to a maximum of twenty.
   ---
   apiVersion: autoscaling/v1
   kind: HorizontalPodAutoscaler
   metadata:
     name: ess-ldp
   spec:
     maxReplicas: 20
     minReplicas: 9
     scaleTargetRef:
       apiVersion: apps/v1
       kind: Deployment
       name: ess-ldp
     # Average CPU usage across all LDP instances in the cluster.
     targetCPUUtilizationPercentage: 40