Azure app service plan

In our previous video we discussed what is App Service. In this video we will discuss App Service Plan.

What is App Service

App Service is a Platform as a Service (PaaS) offering and we use it to host web applications, REST API's and backend services for mobile applications.

What is App Service Plan

To create App Service, you need an App Service Plan. Without an App Service Plan you cannot create App Service. So, in the Azure portal, when you try to create app service, you will have to select an app service plan if you have one already or create a new one. The point is, without an App Service Plan, you cannot create App Service. This is beacuse it is the App Service Plan that defines the compute resources required for your application to run.

How to create App Service Plan

Well, just like any other resource in azure. Search for App Service Plans in the azure protal and click Create.

On Create App Service Plan screen, you specify the following

Name

A name for the App Service Plan. Common convetion is to use the prefix plan. I am going to use this plan for our web application PragimTech.com, so it makes sense to name it plan-pragimtech.

Operating System

The operating system that you want on the underlying virtual machine - Windows or Linux.

Region

The region where you want the App Service Plan to be created.

Pricing Tier

It is the pricing tier that determines what you pay and what you get. Basically the pricing tier you select, determines the following 3 things.

Features available

For example the following are some of the features.

• Custom Domains
• SSL Bindings
• Auto scale
• Staging slots
• Daily backups
• Traffic manager integration

Which of these features are available to your application depends on the pricing tier you select. If you are new to these features and why we need them, please don't worry, we will discuss them in our upcoming videos. For now, what you need to understand is, the features that are available depends on the pricing tier you select. In general, the higher the tier, the more features are available and obviously you also pay more.

For example, if you select S1 pricing tier under production workload, you have all of the above features available. On the other hand, if you select the Free tier from Dev/Test workload, you don't have any of these features available. For example, if you want to be able to scale rescources up and down depending on the demand for your application, you may want to select a pricing tier that supports auto scale feature. With the free pricing tier, you cannot auto scale.

Included hardware

The hardware resources that are available (like memory, storage and the compute power) also depend on the pricing tier you select. One thing I should point out here is, in Azure compute (i.e CPU) performance is compared using something called Azure Compute Unit (ACU for short).

For example, as of this course recording, if you select S1 pricing tier under production workload, you have the following hardware resources available.

• 100 Aazure Compute Units
• 1.75 GB memory per VM instance. For example, the S1 pricing tier supports auto scale feature up to 10 VM instances. Let's say based on the demand for your app and the scaling rules, you have 4 VMs configured. 1.75 GB memory is per VM instance. So this means you have 4 times 1.75 GM memory available for your apps.
• 50 GB Storage - If you want to, you can run multiple applications using a single App Service Plan, but the improtant point to keep in mind is, these hardware resources are shared by all the apps. So this means, each app that is deployed in an App Service Plan gets a slice of computing power, memory and storage.

Please note : As of this course recording, if you compare S1 and P1V2 pricing tiers, S1 provides 100 ACUs (Azure Compute Units), where as P1V2 provides 210 ACUs. So you can say P1V2 is twice as powerful as S1 from computer power standpoint. So the point, that I am trying to get accross is, Azure Compute Units provides a way of comparing compute (CPU) performance. In general, the more Azure Compute Units you have, the more compute power available for your apps running in that App Servic Plan.

The monthly price you pay

Finally the monthly price you pay.