Challenge 07 - Scaling

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Introduction

OpenShift allows users to scale the number of pods for each part of an application as needed. Looking at the deployment definition we have, we stated that we only want one pod to start with. Let’s try and change that!

Description

In this challenge, we will be scaling up the number of pods that we have running in our applications. You will need to:

Scale the rating-api backend application to 4 pods
Scale the rating-web frontend application to 2 pods

Success Criteria

To complete this challenge successfully, you should be able to:

Demonstrate that more than one pod is up and running by either using the following command oc get pods or looking in the ARO Web Console

Learning Resources

Pod Autoscaling (Optional):

This optional section should be done in the ARO Web Console.

NOTE: Before you continue, please read the note at the bottom of this section.

In this part of the challenge you will need to:

Add resource limits to the rating-web frontend deployment
- Set CPU Request: 500m
- Set CPU Limit: 1 core
Add a HorizontalPodAutoscaler to the rating-web frontend deployment
- Set Minimum Pods: 1
- Set Maximum Pods: 3
- Set CPU Utilization: 20%

When the resource limits are set and the HPA is added, let’s see autoscaling in action! To do that:

Copy your frontend application URL to the clipboard
Deploy the following application and replace <rating-web-url> with your frontend application route using the command below:
- NOTE: This will increase the traffic to the frontend application. After a few minutes we should see the rating-web deployment have more than 1 pod deployed
```
kubectl create deployment busybox --image=busybox --replicas=10 -- /bin/sh -c "while true; do wget -q -O- <rating-web-url>; done"
```
When we see the autoscaler in action, we are done with the challenge. Delete the busybox deployment using the command: kubectl delete deployment busybox

NOTE: To autoscale future applications in the CLI and in your production environments make sure to include resource limits in your deployments. That way you won’t need to use the Web Console later on to autoscale or have to redeploy resources! Here are some learning resources to bookmark: