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Azure App Service

Updated Nov 16, 2020 ·
NOTES

This is not an exhaustive documentation of all the existing Azure Services. These are summarized notes for the Azure Certifications.

To see the complete documentation, please go to: Azure documentation

Overview​

When it comes to hosting websites on Azure, there are several options available, each catering to different needs.

  • For static websites without user interactions, Azure Storage is a suitable choice.

  • For more sophisticated requirements, deploying on Azure virtual machines with content management systems or utilizing Azure Kubernetes Service for microservices-based applications are viable options.

However, the most popular and versatile way is through Azure App Service. App Service is a platform-as-a-service (PaaS) offering that simplifies web application deployment while providing flexibility and a rich set of features.

  • It manages the underlying infrastructure, alleviating concerns such as operating system patching.
  • Frameworks come preinstalled and are automatically updated with new patches or releases.
  • Most frameworks allow choosing between Windows and Linux hosting.
  • For applications in different programming languages, App Service supports Docker containers with required dependencies.

Additional features​

  • Well-integrated with Visual Studio and Visual Studio Code.
  • Seamless integration with continuous integration/continuous delivery tools such as Azure DevOps, GitHub, and BitBucket.
  • App Service can host mobile backends and APIs.
  • Guarantees 99.95% uptime in most cases.
  • Configurable to automatically scale resources based on demand.
  • Provides authentication capabilities for restricting access to authorized users.
  • Enables control over allowed or denied IP addresses for site access.

Supported languages​

  • ASP.NET

  • ASP.NET Core

  • Java

  • Ruby

  • Node.js

  • PHP

  • Python

App Service Plan​

When using Azure App Service, one of the critical decisions is configuring the App Service Plan. This defines the type of infrastructure your web application will utilize. The three primary settings to decide in an App Service Plan are the following:

  • Operating System

    • Choose between Windows or Linux based on your application's compatibility and requirements.

  • Region

    • Select the region closest to your target audience for optimal performance.
    • Note: The region is immutable; you can't change it after the plan is created.

  • Pricing Tiers

    • Pricing tiers determine compute resources, features, and costs associated with the App Service Plan.
    • The tiers include Free, Shared, Basic, Standard, Premium, and Isolated.

Pricing Tier​

  1. Free Tier

    • Suitable for development and testing.
    • Provides up to 60 CPU minutes per day.
    • Shared compute resources.

  2. Shared (D1) Tier

    • Offers up to 240 CPU minutes per day.
    • Shared compute resources.
    • Allows the use of a custom domain.

  3. Basic Tier

    • Apps run on dedicated virtual machines.
    • Various options based on CPU cores and memory.
    • All options come with 10 GB of storage.

  4. Standard Tier

    • Similar to Basic tier but with 50 GB of storage.
    • Supports autoscaling.
    • Allows up to 10 VM instances.

  5. Premium Tier

    • More CPU, memory, and storage options.
    • Supports autoscaling.
    • Allows up to 30 VM instances.

  6. Isolated Tier

    • Provides a private, dedicated environment.
    • VMs in their own virtual network, isolated from other App Service instances.
    • Allows up to 100 VM instances.

Scaling​

  • Scaling Out (Horizontal Scaling)

    • Add more virtual machine instances, up to the limit of the selected pricing tier.
    • Multiple apps within the same service plan share compute resources.

  • Scaling Up (Vertical Scaling)

    • Switch to a pricing tier with more powerful instances or a higher limit on the number of instances.
    • Easy to perform, taking effect in seconds.

Considerations​

  • Multiple Apps in a Service Plan

    • Possible, but all apps share the same compute resources.
    • Excessive apps in one plan may lead to performance issues.

  • Scaling Strategies

    • Choose between scaling out (horizontal) and scaling up (vertical) based on performance needs.

    • Autoscaling is a more advanced scaling strategy covered in a separate course.

Resources​