We are happy to announce an upgrade to the App Service Environment. The App Service Environment (ASE) is a powerful feature offering of the Azure App Service that gives network isolation and improved scale capabilities. It is essentially a deployment of the Azure App Service into a subnet of a customer’s Azure Virtual Network (VNet). While the feature gave customers what they were looking for in terms of network control and isolation, it was not as “PaaS like” as the App Service was normally. We took the feedback to heart and for ASEv2 then we focused on making the user experience the same as it was in the multi-tenant App Service while still providing the benefits that the ASE provided. To make things clearer I will use the abbreviation ASEv2 to refer to the new App Service Environment and the initial version as ASEv1.
The App Service Plan (ASP) is the scaling container that all apps are in. When you scale the ASP you are also scaling all of the apps in the ASP. This is true for the multi-tenant App Service as well as the ASE. This means that to create an app you need to either choose an ASP or create an ASP. When you wanted to create an ASP in ASEv1 you needed to pick an ASE as your location and then select a worker pool. If the worker pool you wanted to deploy into didn’t have enough capacity then you would have to add more workers to it before you could create your ASP in it.
Read more about it in the Azure blog.