Configure autoscale

  • 3 minutes

When you create an Azure Virtual Machine Scale Sets implementation in the Azure portal, you can enable manual or autoscaling. For optimal performance, you should define a minimum, maximum, and default number of virtual machine instances to use.

In the Azure portal, you can select the scaling mode.

Screenshot of the settings for selecting a scale method in the Azure portal.

Scaling mode

  • Manually update the capacity: Maintain a fixed instances count. Set the Instance count to the number of virtual machines in the scale set (0 - 1000). Configure the Scale-in policy which is the order virtual machines are selected for deletion. For example, you could balance across zones and then delete the virtual machine with the highest instance ID.

  • Autoscaling: Scaling based on a CPU metric, or any schedule.

Configure autoscaling

Autoscaling is based on a scaling condition.

Screenshot of the settings for configuring virtual machine instances and autoscale in the Azure portal.

  • Default instance count. The initial number of virtual machines deployed in this scale set (0-1000).

  • Instance limit. The minimum instance count you want this condition to scale down to. The maximum instance count you want this condition to scale up to.

  • Scale out. The CPU usage percentage threshold for triggering the scale-out autoscale rule. The number of instances to scale out by.

  • Scale in. The CPU usage percentage threshold for triggering the scale-in autoscale rule. The number of instances to scale in by.

  • Query duration: This duration is the time the Autoscale engine looks back for the metric usage average. This look back is to allow your metric to stabilize.

  • Schedule: Specify the start and end dates. You can also repeat the schedule on specific days.