Horizontal Pod AutoScaler (HPA)
hpa, please make sure you have deployed the application as explained in section
Deploy Application to IKS.
Run the following command to configure HPA.
kubectl autoscale deployment test --cpu-percent=25 --min=1 --max=5
This HPA scales up when CPU exceeds 25% of the allocated container resource.
You can view the HPA using kubectl. You probably will see
<unknown>/25% for 1-2 minutes and then you should be able to see 0%/25%.
kubectl get hpa
In the code repository,
generate-load-hpa.yml is provided, which is used to increase the load on CPU. It creates 10 replicas of a container where each container calls CPU intensive operation in a loop.
generate-load-hpa.yamlas shown.## macOS$ sed -i '' s#HOST#<YOUR_INGRESS_SUBDOMAIN># generate-load-hpa.yaml## Linux$ sed -i s#HOST#<YOUR_INGRESS_SUBDOMAIN># generate-load-hpa.yaml
Run the following command from the terminal to increase load.kubectl create -f generate-load-hpa.yaml
In a terminal, you can check the number of pods created.
kubectl get pods
In the another tab, watch the HPA with the following command:
kubectl get hpa -w
You will see HPA scale the pods from 1 up to our configured maximum (5).
The resource usage can also be checked through Kubernetes dashboard. Access the dashboard, it will show something like this.
You can now stop load using the following command.
kubectl delete deployment load-generator
You will notice that HPA will slowly bring the replica count to min number based on its configuration.
Once the replica count reaches to 1, it means it has scaled-down properly after decreasing load on CPU. Then we can clean-up the hpa configuration using the following command.
kubectl delete hpa test