CODEWITHSUNDEEP
azureazure-resource-manager
Stephen
Stephen

Reputation: 61

Autoscaling IaaS VMs in ARM mode from a template

I've created an template-based deployment that over-provisions a number of Linux VMs. I'd like to autoscale them as per classic instances, where Azure will turn on/turn off instances according to CPU load.

Is this possible with ARM mode? And if not, is there a suggested alternative method? The only examples I can find are around using Application Insights and PaaS functionality. I've got a Python app running in Docker on Ubuntu hosts.

Upvotes: 3

Views: 1951

Answers (2)

Jimmy R
Jimmy R

Reputation: 558

For IaaS, you must use virtual machine scale sets to use autoscale, else you need to stick with PaaS (web apps).

Upvotes: 1

tripdubroot
tripdubroot

Reputation: 1153

For this you would first need to create an availability group for the VMs. The resource decleration in the ARM template looks something like this:

{
 "type": "Microsoft.Compute/availabilitySets",
  "name": "[variables('availabilitySetName')]",
  "apiVersion": "2015-05-01-preview",
  "location": "[parameters('location')]",
  "properties": {
       "platformFaultDomainCount": "2"
   }
}

Then for the virtual machine resource the decliration in the ARM Template would look something like this:

    {
            "apiVersion": "2015-05-01-preview",
            "type": "Microsoft.Compute/virtualMachines",
            "name": "[concat(variables('vmName'), '0')]",
            "location": "[parameters('location')]",
            "dependsOn": [
                "[concat('Microsoft.Storage/storageAccounts/', parameters('newStorageAccountName'))]",
                "[concat('Microsoft.Network/networkInterfaces/', variables('nicName'), '0')]",
                "[concat('Microsoft.Compute/availabilitySets/', variables('availabilitySetName'))]"
            ],
            "properties": {
                "availabilitySet": {
                    "id": "[resourceId('Microsoft.Compute/availabilitySets', variables('availabilitySetName'))]"
                }, 
      ...},

The quckstart templates are a good ref: https://raw.githubusercontent.com/azure/azure-quickstart-templates/master/201-2-vms-2-FDs-no-resource-loops/azuredeploy.json

Once you have two or more VMs of the same size in an availability set, you would configure autoscale using microsoft.insights/autoscalesettings, which I beleive you referenced in the question. This is done at the cloud service so it will work similar to PaaS... like so:

{
      "apiVersion": "2014-04-01",
      "name": "[concat(variables('vmName'), '-', resourceGroup().name)]",
      "type": "microsoft.insights/autoscalesettings",
      "location": "East US",
      ...},

A pretty good example is here: https://raw.githubusercontent.com/Azure/azure-quickstart-templates/6abc9f320e39d9d75dffb60846e88ab80d3ff33a/201-web-app-sql-database/azuredeploy.json

I also setup autoscale using the portal first and reviewed ARMExplorer to get a better idea of how things should look in my code. ARMExplorer is here: Azure Resource Explorer

Upvotes: 0

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