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Concepts

This section explains Azure App Service platform behavior in a language-agnostic way. Use these documents to understand architecture, scaling, networking, and dependency relationships before diving into language-specific implementation details.

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Documents

Document Description
How App Service Works Platform architecture, sandbox model, filesystem, runtime contracts
Hosting Models Plan tiers, OS choices, code vs container deployment models
Request Lifecycle End-to-end request path, routing, timeouts, health checks
Process Lifecycle and In-Flight Work Maintenance replacement, recycle evidence, and interruption-safe work design
Scaling Scale up/out strategies, autoscale rules, stateless design
Networking Inbound and outbound controls, private networking, DNS patterns
Mutual TLS Architecture Inbound client certificates, outbound certificate loading, and ASE trust boundaries
Resource Relationships Identity, data, storage, secrets, monitoring integration map
Authentication Architecture EasyAuth flow, token handling, identity provider integration
Security Architecture Network perimeter, TLS, managed identity, secret management 
graph TD
    A[How App Service Works] --> B[Hosting Models]
    B --> C[Request Lifecycle]
    C --> D[Scaling]
    D --> E[Networking]
    E --> F[Mutual TLS Architecture]
    F --> G[Resource Relationships]
    G --> H[Authentication Architecture]
    H --> I[Security Architecture]
  1. Start with platform internals
  2. Choose hosting and plan strategy
  3. Learn request flow and timeouts
  4. Design scaling envelope
  5. Finalize networking controls
  6. Validate resource relationships and permissions

Verify platform surfaces in Azure Portal

Azure portal Overview blade for `app-appsvc-guide-recap` (Web App) with a command bar (`Browse`, `Stop`, `Swap`, `Restart`, `Delete`, `Refresh`, `Download publish profile`, `Reset publish profile`, `Share to mobile`, `Send us your feedback`) and an Essentials panel showing Resource group `rg-p2b-recapture`, Status `Running`, Location `Korea Central`, Subscription `Visual Studio Enterprise Subscription`, Subscription ID `00000000-0000-0000-0000-000000000000`, Default domain `app-appsvc-guide-recap.azurewebsites.net`, App Service Plan `plan-p2b-recapture (B1: 1)`, Operating System `Linux`, and Health Check `Not Configured`. The Properties tab is selected (next to Monitoring, Logs, Capabilities, Notifications (0), Recommendations) and surfaces Web app (`Name: app-appsvc-guide-recap`, `Publishing model: Code`, `Runtime Stack: Python - 3.11`, `Runtime status: Healthy`), Domains (`Default domain: app-appsvc-guide-recap.azurewebsites.net`, `Custom domain: Add custom domain`), Hosting (`Plan Type: App Service plan`, `Name: plan-p2b-recapture`, `Operating System: Linux`, `Instance Count: 1`, `SKU and size: Basic (B1)` with `Scale up` link), Deployment Center (`Last deployment: No deployments found`, `Deployment provider: None`), Application Insights (`Name: Enable Application Insights`), and Networking (`Inbound IP addresses: 192.0.2.1, 2001:db8::1`, `Private endpoint connections: 0 private endpoints`, `Virtual network integration: Not configured`). Left nav under the search box lists Overview (selected), Activity log, Access control (IAM), Tags, Diagnose and solve problems, Microsoft Defender for Cloud, Events (preview), AI (preview), Resource visualizer, a Favorites group (Networking, API definition), and collapsed groups Deployment and Settings.

[Observed] app-test-20251107 Web App Browse Stop Swap Restart Delete Refresh Download publish profile Reset publish profile Share to mobile Send us your feedback Essentials View Cost JSON View Resource group (move) rg-test-20251107 Status Running Location (move) Korea Central Subscription (move) Visual Studio Enterprise Subscription Subscription ID 00000000-0000-0000-0000-000000000000 Tags (edit) Add tags Default domain app-test-20251107.azurewebsites.net App Service Plan asp-test-20251107 (P0v3: 1) Operating System Linux Health Check Not Configured Properties Monitoring Logs Capabilities Notifications (1) Recommendations Web app Name Publishing model Code Runtime Stack Python - 3.11 Runtime status Healthy Domains Custom domain 2 Domains View all Hosting Plan Type App Service plan Instance Count 1 SKU and size Premium0V3 (P0v3) Scale up Deployment Center Deployment logs View logs Last deployment Deployment provider None Application Insights Name ai-test-20251107 Region Korea Central Networking Inbound IP addresses <ip-redacted>, <ipv6-redacted> Private endpoint connections 0 private endpoints Virtual network integration Not configured.

[Inferred] The Plan Type value App Service plan and the SKU and size value Premium0V3 (P0v3) appearing in the Hosting section are consistent with the hosting-tier topics referenced in the Hosting Models row of the Documents table above. The Inbound IP addresses, Private endpoint connections, and Virtual network integration rows of the Networking section are consistent with the inbound and outbound topics referenced in the Networking row of the Documents table. The Application Insights section listing ai-test-20251107 is consistent with the monitoring-integration topic referenced in the Resource Relationships row.

[Not Proven] Additional configuration detail, historical detail, and linked-resource detail are not visible on this view.

Advanced Topics

  • Build architecture decision records (ADRs) per environment
  • Standardize plan tier baselines by workload class
  • Define SLO-driven scaling and networking review checkpoints

Language-Specific Details

For language-specific implementation details, see: - Node.js Guide - Python Guide - Java Guide - .NET Guide

See Also

Sources