What is different azure function app and app service plan? - azure

What is different azure function app and app service plan ?
I think;
Function app is a core layer - where hosted code and execute
App service plan is higher layer of function app - it can be covering function app. For example, it can cover network layer for function app.
But I see in function app has Vnet integration feature and app service plan has virtual network integration too.
I am confused with it.
What is different azure function app and app service plan in network part ?
p/s: I have created virtual network and assign app service plan to that VNET. then I deployed a function app into app service, but this function does not stay in that VNET. how to verify that ?

There are a few things that will help you to understand this little better and you can also verify through Azure Portal. After all, it's all the hosting plan you want to use.
App Service Plan: This is something a root consumption plan you are paying for. kind of resources you want for much of your work. (I would say - choose this wisely)
Function App: This resource has 3-4 different kinds of hosting plan options
(i) Consumption plan (ii) Premium Plan (iii) App Service Plan (iV) ASE.
now, if you have notice - App Service Plan (item iii) is also one of the options. Not necessary that is only an option. So, in other words; Function App can sit outside the App Service plan (like Consumption plan) where it will deploy separately.
At this moment Question might come - what could be a difference. for that visit Microsoft's well-documented link here which states you are paying and resources are getting allocated during the function real-use whereas, App Service Plan uses your own app Dedicated service plan which you already have decided a lot earlier in the cycle.
Your last question - How do we confirm? well, Open App Service Plan inside Azure Portal and there is an essential section where you will find App(s)/ Slot(s). Click on that you will see how many app services/ function apps already sharing that specific App Service Plan like below:

An App Service Plan is the environment which you pay for.
You can then run different workloads including function apps within the App Service Plan. Grouping workloads in a single App Service Plan can save you money compared with having different App Service Plans for each App Function.
The VNET configuration is both at the App Service Plan and the App Service / Function App level. You do not necessarily want all App Services / Function Apps in the same App Service Plan to run on the same VNET.

The consumption plan is based on function runtime, which means only when your function is running else no.
Premium plan you need to specify prewarmed instances that will always be online. so it's kind of minimum fixed billing and it can go beyond if you use it for resources.
The app service plan (Dedicated plan) is Running function like other apps. It will use the same app service plan.
Refer to this documentation for more details.

Related

Change App Service Plan from Isolated to Isolated V2 Plan for a Web App

We want to change the App Service Plan of an existing Azure Web App, from Isolated Service Plan to Isolated "v2" Service Plan. There are no changes in Subscription, Resource Group or Region. One condition for us is, we want to continue using same the Web App with the Plan alone changed. Please let me if this possible and how can we change this.
I could see the "Change App Service Plan" option in Azure Portal but I am unable to exactly find it out regarding the Plan change by dabbling in it.
We are able to create the required Isolated V2 Plan separately but we are unable to switch the Web App to the new Plan so far.
Referring the Microsoft documentation, I keep coming across that different kinds of App Service Environments(ASE) are used for the above Plans, it is not clear due to different ASEs, the Plan change is possible or not.
For quick reference, I have sketched out my query below:
Azure Web App : Web-App-1
App Service Plan : Isolated Service Plan
to
Azure Web App : Web-App-1
App Service Plan : Isolated V2 Service Plan
(Same Region, Subscription and Resource Group)
when you try and change to the new ASP, Azure will perform a check to see if it is a valid move, so as long as you can see it in the destination combo box uner the change app service plan option you can try and let azure evaulate if the move is possible.
If you cannot see it as a destination then you might be able to clone the ASP because the two ASP's you have might be in a different webspace which you cannot do anything about.
Change App Service Plan from Isolated to Isolated V2 Plan for a Web App
I keep coming across that different kinds of App Service Environments(ASE) are used for the above Plans, it is not clear due to different ASEs, the Plan change is possible or not.
The private environment used with an Isolated plan is called the App Service Environment v2 and with Isolated v2 Service Plan is called the App Service Environment v3.
Apps can only move between plans that are created in the same webspace, where webspace is a internal deployment unit of App Service Plan.
Apps cannot be moved between plans in different App Service Environments.
Make sure you created the App Service Environment v3 to change your web app to Isolated V2 SKU.
To know more information on changing the app service plans along with its SKU Sizes and its limitations, please refer this Microsoft Documentation and regarding the app service environments versions of Isolated Plans, refer App Service pricing.

How to design the environments hosting (dev, stage, prod) for my Azure API App?

I'm writing an API that will basically provide services to read and write to a Database.
My goal would be to have three environment. Dev, Stage and Production.
The first idea was to have three different resource groups, each with three different App Service Plans to host each environment.
Then i started reading and the recommended strategy seems to be to have all of the environments hosted within one App Service Plan. This way you could take advantage of swapping deployment slots. Also I'd be paying one third of the price.
But i also read that it's good to have a production environment isolated from the rest. So this way I'd need one App Service Plan for Prod, and another one for the rest of my environments.
So my first question is, is there a suggested/standard way to proceed setting up environments?
Is swapping exclusive to environments within a single App Service Plan?
Also i was comparing specs of Standard, Premium and Isolated tiers, and i couldn't find info on if Isolated App Services Plan have 'Staging Slots' for deployment. I know that Standard tier comes with 5 slots and Premium tier has 20. Does Isolated App Service Plans not support multiple deployment slots?
Thanks in advance for any insight that you guys can provide me.
is there a suggested/standard way to proceed setting up environments?
As far as I know, it is convenient for us to create deployment slot in the azure portal when the app is running in the Standard or Premium App Service plan tier.
Add a deployment slot
In the azure portal, open your app's resource blade-->Deployment slots-->Add Slot-->give the slot a name and select Configuration Source. If you have several slots, you could swap them manually or set the Auto Swap.
Configuration for deployment slots
When you using the swap feature, you should know the settings that can be swapped or not. Also, you could set slot setting, note that marking a configuration element as slot specific has the effect of establishing that element as not swappable across all the deployment slots associated with the app.
For more details, you could refer to this article.
Is swapping exclusive to environments within a single App Service Plan?
Per my understanding, App Service Plan is like a VM, it holds your app, deployment slot is like a copy of the web app that you can make different configurations. It also be held with the App Service Plan. If the App Service Plans have different pricing tier, they will have different features. So we could not swap the slots in different Service Plans.
Does Isolated App Service Plans not support multiple deployment slots?
Actually, Isolated App Service Plan supports deployment slots.You could view full details for App Service Plans.The Isolated tier is special.In the Isolated tier, the App Service Environment defines the number of isolated workers that run your apps, and each worker is charged hourly. In addition, there's an hourly base fee for the running the App Service Environment itself.
You could select the tier when creating the App Service Plan, but cannot scale up to this tier in the scale up option in the resource blade.

Can Azure Functions live on the same App Service as a WebAPI, for example?

I want to consolidate a collection of Azure Functions and a WebAPI on the same App Service. Can't figure out the best way to go about it and be able to manage both solutions in the portal.
An App Service plan supports multiple resources deployed to it: Function apps, Api apps, Web apps, etc. There shouldn't be any issue doing this.
Each app deployed to a service plan will get its own uri and local storage, but will share the app service plan's capacity (e.g. if you have an S2 plan running on 3 instances, all of your deployed apps to that App Service plan will run on all 3 instances, utilizing the resources of the S2-based instances).
Instances of the same app share disk resources. Your different apps are isolated from each other.
You can't run them in the same site (ie, with the same URL like mysite.azurewebsites.net). Although you could use Function Proxies to forward out part of the function url namespace to the WebAPI. Your azure function and WebAPI would be 2 separate entities in the portal, similar to having 2 separate WebAPIs.
As others have said, this is possible.
For the function app, you need to choose "app service plan", not "consumption based".
You also need to have an app service plan which isn't on the Free or Shared tier. i.e. it has to be a minimum of B1 - no minutes/hour usage limits.

Set up an azure botframework application to be 'always on'

When I configure a new azure bot service application on Azure, it creates it as a consumption pricing tier application. This seems to possibly be causing issues on cold starts where the application takes quite a long time (in comparison to a running application) to respond.
I would like to configure the application to use a resource group that is on an basic plan so that I can make it 'always on'.
Is there a setting I am missing or is this just not possible at this time?
Edit: I am OK with paying for the ability to enable "Always On" like I can with the typical Azure Function/web apps. At this point I do not see a way to configure a bot application to allow it to be anything but a consumption based application.
Edit2: clarified that this is an azure bot service application
Are you creating an SDK bot, or an Azure Bot Service bot? SDK bots are just web applications, and can be in any consumption pricing plan (including Always On): https://learn.microsoft.com/en-us/azure/app-service-web/web-sites-configure
Azure Bot Service bots are function applications. They should also be provisional within an App Service plan: https://learn.microsoft.com/en-us/azure/azure-functions/functions-scale
Edit:
From above documentation: you will need to setup a VM to host an Azure Function as Always On.
App Service plan
In the App Service plan, your function apps run on dedicated VMs on
Basic, Standard, and Premium SKUs, similar to Web Apps. Dedicated VMs
are allocated to your App Service apps, which means the functions host
is always running. Consider an App Service plan in the following
cases: You have existing, underutilized VMs that are already running
other App Service instances. You expect your function apps to run
continuously, or nearly continuously. You need more CPU or memory
options than what is provided on the Consumption plan. You need to run
longer than the maximum execution time allowed on the Consumption
plan. A VM decouples cost from both runtime and memory size. As a
result, you won't pay more than the cost of the VM instance that you
allocate. For details about how the App Service plan works, see the
Azure App Service plans in-depth overview.

How does scaling out work in Azure App Services?

I am trying to wrap my head around the concept of Azure App Service plan and Azure App Services, with no luck.
My understanding is that an App Service Plan defines the capacity and the pricing, all apps assigned to a specific App Service plan will share the same resources, is that right?
If that is right, then what is the benefit of the scaling-out? If the scale out will create more instances of the same app which at the end will be hosted on the same App Service Plan (sharing the same resources)?
I read almost all the official and non-official documentation about Azure App Service plan and App Services but couldn't find an answer to this question, they are all saying that scaling is working on the app level (not the app service plan) and at the same time saying that the apps assigned to the same app service plan are actually sharing the same resources, so what is the benefit of the scale-out feature?
Regards,
My understanding is that an App Service Plan defines the capacity and
the pricing, all apps assigned to a specific App Service plan will
share the same resources, is that right?
Yes.
If that is right, then what is the benefit of the scaling-out? If the
scale out will create more instances of the same app which at the end
will be hosted on the same App Service Plan (sharing the same
resources)?
No one forces you to put all your apps on the same App Service Plan. When you create an App you put it into some App Service Plan. All the Apps on that (and only that) App Service Plan would share resources, but you could create a lot of App Service Plans.
Also, when you scale out you create more PaaS instances of the VM's hosting your App, so when you scale out you are not getting another App Pool in the same IIS, you are getting another App Pool on the other IIS on the other VM.
edit: to clarify the comment, the App Service Plan is a collection of Windows VM's with IIS installed on them. All the Apps assigned to that App Service Plan are hosted on ALL the instances of those VM's, when you scale out or scale up you change the number or capacity of those VM's.
There's no temporary App Service Plan. You pay for the Service Plan, not for the App. Apps cost nothing, they are simply consuming resources on the Service Plan, its the Service Plan that "eats" money. You are getting billed according to the Service Plan tier and scale.
Pricing is based on the size and number of VM instances you run.
As I know, the scale out would create multiple copies of your web app and add a Load Balance to distribute the requests between them automatically. And you don't need to configure the load balance separately by yourself.
Assuming that you create a website (a windows server with IIS), then your website would has the App Pool which defines the available resources for your website. Each instance could handle a limited number of requests, in order to reduce the response time, you could scale out your website into multiple instances, then each web-server could split the work load. For more details, you could refer to Scaling Up and Scaling Out in Windows Azure Web Sites and this tutorial for a better understanding of Azure Web App auto scale.
As #4c74356b41 said when you scale out you are going to get more physical resources (i.e VM's with more compute, memory and storage). Also one correction as per Azure documentation, scale out is going to effect all apps in app service plan. see below link and the point to note is
"The scale settings take only seconds to apply and affect all apps in your App Service plan. They do not require you to change your code or redeploy your application" -
https://azure.microsoft.com/en-us/documentation/articles/web-sites-scale/
The docs answer this clearly: https://learn.microsoft.com/en-us/azure/app-service/overview-hosting-plans#how-does-my-app-run-and-scale
In this way, the App Service plan is the scale unit of the App Service apps. If the plan is configured to run five VM instances, then all apps in the plan run on all five instances. If the plan is configured for autoscaling, then all apps in the plan are scaled out together based on the autoscale settings.

Resources