Azure App Service plans Flashcards
App Service plan
In App Service, an app always runs in an App Service plan. An App Service plan defines a set of compute resources for a web app to run. One or more apps can be configured to run on the same computing resources (or in the same App Service plan).
App Service plan defines
Operating System (Windows, Linux)
Region (West US, East US, etc.)
Number of VM instances
Size of VM instances (Small, Medium, Large)
Pricing tier (Free, Shared, Basic, Standard, Premium, PremiumV2, PremiumV3, Isolated, IsolatedV2)
Pricing tiers of an App Service
Shared compute: Free and Shared, the two base tiers, runs an app on the same Azure VM as other App Service apps, including apps of other customers. These tiers allocate CPU quotas to each app that runs on the shared resources, and the resources can’t scale out.
Dedicated compute: The Basic, Standard, Premium, PremiumV2, and PremiumV3 tiers run apps on dedicated Azure VMs. Only apps in the same App Service plan share the same compute resources. The higher the tier, the more VM instances are available to you for scale-out.
Isolated: The Isolated and IsolatedV2 tiers run dedicated Azure VMs on dedicated Azure Virtual Networks. It provides network isolation on top of compute isolation to your apps. It provides the maximum scale-out capabilities.
How does an app run and scale?
An app runs on all the VM instances configured in the App Service plan.
If multiple apps are in the same App Service plan, they all share the same VM instances.
If you have multiple deployment slots for an app, all deployment slots also run on the same VM instances.
If you enable diagnostic logs, perform backups, or run WebJobs, they also use CPU cycles and memory on these VM instances.
Isolate your app into a new App Service plan when:
The app is resource-intensive.
You want to scale the app independently from the other apps in the existing plan.
The app needs resource in a different geographical region.
