App Services Core Concepts

Microsoft Azure App Services is a cloud-based platform for building, deploying, and scaling web applications, mobile backends, and RESTful APIs. This document outlines the fundamental concepts you need to understand to effectively utilize Azure App Services.

Key Concepts

1. App Service Plan

An App Service plan defines a set of computing resources for your web apps to run. It's like a virtual machine that hosts your applications. You choose a pricing tier (Free, Shared, Basic, Standard, Premium) and region for your plan, which determines the performance, features, and cost. All apps within the same plan share the underlying resources.

• Pricing Tiers: Each tier offers different levels of CPU, memory, storage, and features.
• Regions: Deploy your apps close to your users for lower latency.
• Scaling: App Service Plans allow for both manual and automatic scaling of your applications.

2. Web App

A Web App is the primary resource you create within an App Service plan. It's the instance that hosts your web application. You can deploy code from various sources, including Git repositories, FTP, and CI/CD pipelines.

• Deployment Slots: Deploy new versions of your app to a staging slot before swapping them into production, enabling zero-downtime deployments.
• Custom Domains and SSL: Easily map your custom domain names and secure them with SSL certificates.
• Authentication and Authorization: Integrate with identity providers like Azure Active Directory, Facebook, Google, and more.

3. Deployment Slots

Deployment slots are live, but separate, instances of your web app. They are useful for managing deployments and reducing downtime. You typically have a production slot and one or more staging slots.

• Staging: Deploy to a staging slot, test thoroughly, and then swap it into production.
• Rollback: If a deployment causes issues, you can quickly swap back to a previous stable slot.

4. Scaling

Scaling allows your application to handle varying loads. Azure App Services offers two main types of scaling:

• Scale Up: Increase the capacity of your existing instances by moving to a higher pricing tier within your App Service Plan (e.g., from Basic to Standard).
• Scale Out: Increase the number of instances running your app. This can be done manually or automatically based on metrics like CPU usage, memory, or HTTP queue length.

5. App Service Features

Beyond the core concepts, App Services provides a rich set of features to enhance your applications:

• Continuous Integration/Continuous Deployment (CI/CD): Integrate with Azure DevOps, GitHub, and other providers for automated deployments.
• Monitoring and Diagnostics: Use Application Insights and Azure Monitor for deep insights into application performance and health.
• Networking: Configure virtual networks, hybrid connections, and access restrictions.
• Backup and Restore: Schedule regular backups of your app and its data.

Understanding these core concepts will provide a solid foundation for building and managing your applications on Azure App Services.