Autoscaling of VM

Amazon AWS state:

You should use AWS Auto Scaling if you have an application that uses one or more scalable resources and experiences variable load. A good example would be an e-commerce web application that receives variable traffic through the day.

Autoscaling isn’t just for workloads running in a public cloud or Hyperscalers. We can achieve the same functionality running in your data center on premises within VMware.

We need to run some tools to achieve this. I am sure you can accomplish the same with configuration management tools.

Let us look at how to autoscale when the VM in question hits a threshold of 95% consumption over a 10-minute duration. In this example we will perform horizontal scaling, meaning adding a second VM.

Prerequisites:

• VMware Aria Automation is fully set up and integrated with VMware Aria Operations (formerly vRealize Operations) for monitoring and alerting.
• VMware Aria Orchestrator workflows are available for automation tasks.
• The necessary permissions to create and modify policies, blueprints, and workflows.

Step-by-Step Configuration

1. Configure Monitoring in VMware Aria Operations

• Set Up Metric Collection:
  • Ensure that the VMs are being monitored by VMware Aria Operations and that CPU usage metrics are being collected.
• Create a Custom Alert Definition:
  • Go to the Alerts tab in VMware Aria Operations.
  • Create a new alert definition that triggers when the CPU usage of a VM exceeds 95% for 10 minutes.
  • Criteria:
  • Base Object Type: Virtual Machine.
  • Condition: CPU usage (%) > 95%.
  • Duration: 10 minutes.
  • Alert Impact: Set the impact to Performance.
  • Notification: Enable notifications to send alerts via email or other channels.

2. Create a Scaling Workflow in VMware Aria Orchestrator

• Define a Workflow for Scaling:
  • In VMware Aria Orchestrator, create a workflow that will perform the scaling action (e.g., add more vCPUs or clone a new VM).
  • Scaling Options:
    • Horizontal Scaling: Clone a new instance of the VM or deploy a new VM from a blueprint.
    • Vertical Scaling: Increase the number of vCPUs or memory for the existing VM.
  • Input Parameters: The workflow should accept inputs such as the VM name, resource settings (vCPU, memory), etc.
  • Action: Implement the logic to scale the VM (e.g., via a PowerCLI script or vSphere API calls).

3. Integrate VMware Aria Operations with Aria Automation

• Create a Subscription:
  • In VMware Aria Automation, navigate to the Subscriptions section.
  • Create a new subscription that listens to the alert from VMware Aria Operations.
  • Filter: Set the filter criteria to trigger when the alert (CPU > 95% for 10 minutes) is received.
• Attach Workflow to Subscription:
  • Attach the scaling workflow you created in VMware Aria Orchestrator to this subscription.
  • This will trigger the workflow whenever the alert conditions are met.

4. Create and Apply Auto-Scaling Policies

• Define Auto-Scaling Policies:
  • In VMware Aria Automation, define a policy for auto-scaling that uses the subscription and workflow created earlier.
  • Set the policy to monitor CPU usage and take the scaling action automatically.
• Apply Policy to VMs:
  • Apply this auto-scaling policy to the specific VMs or VM groups that need auto-scaling based on CPU usage.

5. Test the Configuration

• Simulate High CPU Load:
  • Generate a high CPU load on the VM to test the auto-scaling configuration.
  • Monitor the VM’s performance and verify that the scaling action is triggered when CPU usage exceeds 95% for 10 minutes.
• A good tool for this is CpuStress by Microsoft (If you run Windows) https://learn.microsoft.com/en-us/sysinternals/downloads/cpustres
• For Linux – Stress is a great tool https://linux.die.net/man/1/stress

6. Monitor and Adjust

• Monitor Scaling Actions:
  • Use VMware Aria Operations to monitor the scaling actions and ensure they are executed as expected.
• Fine-Tune Alert Thresholds:
  • If necessary, adjust the alert thresholds or scaling logic based on the observed performance.

Summary

Following these steps, you can configure VMware Aria Automation to automatically scale a VM when its CPU usage exceeds 95% for 10 minutes. This involves setting up alerts in VMware Aria Operations, creating scaling workflows in VMware Aria Orchestrator, and integrating these with VMware Aria Automation policies.