General Availability: Automatic Scaling for App Service Web Apps

Azure App Service is pleased to announce general availability of the "Automatic Scaling" feature. We received important feedback about the Automatic Scaling feature during the preview phase and have made following enhancements to the Automatic Scaling feature.  

• Automatic scaling is available for Premium V2 (P1V2, P2V2, P3V2) and Premium V3 (P0V3, P1V3, P2V3, P3V3, P1MV3, P2MV3, P3MV3, P4MV3, P5MV3) pricing tiers, and supported for all app types: Windows, Linux, and Windows container. 
• A new metric viz. "Automatic Scaling Instance Count" is now available for web apps where Automatic Scaling is enabled. AutomaticScalingInstanceCount will report the number of virtual machines on which the app is running including the pre-warmed instance if it is deployed.

In addition to these enhanced capabilities please remember that the automatic scaling feature continues to support following key capabilities:

• The App Service platform will automatically scale out the number of running instances of your application to keep up with the flow of incoming HTTP requests, and automatically scale in your application by reducing the number of running instances when incoming request traffic slows down.
• Developers can define per web app scaling and control the minimum number of running instances per web app.
• Developers can control the maximum number of instances that an underlying app service plan can scale out to. This ensures that connected resources like databases do not become a bottleneck once automatic scaling is triggered.
• Enable or disable automatic scaling for existing app service plans, as well as apps within these plans.
• Address cold start issues for your web apps with pre-warmed instances. These instances act as a buffer when scaling out your web apps.
• Automatic scaling is billed on per second basis and uses the existing Pv2 and Pv3 billing meters.

• Pre-warmed instances are also charged on per second basis using the existing Pv2 and Pv3 billing meters once it's allocated for use by your web app.

For more information about Automatic Scaling Feature please refer to:

How to enable automatic scaling - Azure App Service | Microsoft Learn

Announcing General Availability of Azure App Service Automatic Scaling