Managed PaaS hosting for web apps and Web App for Containers, run in a sandbox without OS access. Deployment slots and autoscale start at the Standard tier.
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In the Ultra Transcenders books
Each book explains App Service in context, with comparison tables and the common traps.
Terms in this definition
- PaaS
Platform as a service, managed offerings such as Azure SQL Database and App Service in which the provider looks after the infrastructure and operating system.
- Web App for Containers
The App Service offering for running containers, with Easy Auth, autoscaling and continuous deployment from ACR built in.
- Deployment slots
Extra App Service environments, available from the Standard tier, that you warm up and then swap with production, keeping the ability to swap back.
- Autoscale
Azure Monitor capability that adds or removes instances on a schedule or once a metric rule has been true for its full duration. The maximum instance count merely sets a ceiling and never triggers scaling itself.
- S0 pricing tier (Foundry Tools)
Name of the standard paid tier for Foundry, Azure OpenAI and most Foundry Tools. Exceptions: Computer Vision calls its standard tier S1, and Document Intelligence offers nothing beyond F0 and S0.
Related terms
- Access restrictions
Allow and deny rules for inbound App Service traffic, matched on IP range, service tag or subnet. They can, for instance, restrict an app to a corporate NAT's public addresses.
- App Service Authentication
Code-free sign-in feature of App Service, also called Easy Auth, supporting Microsoft Entra ID along with other identity providers.
- App Service custom domain
Host name bound to an App Service app once the service has confirmed an asuid TXT record and an A or CNAME record. Serving it over HTTPS also requires binding a TLS certificate.
- App Service Environment
Network-isolated, single-tenant deployment of App Service on the Isolated plan. Because its cost is much higher, it suits only workloads that demand isolation.
- App Service Health check
An App Service feature that calls a path you choose on each instance every minute, takes persistently failing instances out of load balancing and replaces those still unhealthy after an hour.
- App settings
Environment variables injected into an App Service app as name/value pairs, taking precedence over values in appsettings.json or Web.config. Each can be marked as specific to a slot.
- Auto-instrumentation
Turning on Application Insights for an app without changing its code, for instance through the App Service blade.
- Auto swap
An App Service deployment slot option that, after each deployment and once warm-up finishes, swaps that slot into production without manual action. Linux web apps and Web App for Containers can't use it.