There are 10 VMs in Isolated tier and there are 10 deployment slots. I've 10 continuous webjobs one per each slot running in singleton mode. Can I expect webjobs to be distributed across VMs in 1:1 ratio i.e, 1 webjob per VM? Or is the distribution of webjobs done randomly?
As you might be aware of that Isolated tiers run dedicated Azure VMs on dedicated Azure Virtual Networks and It provides network isolation on top of compute isolation to your apps.
With the dedicated app plans means each web app is running on it’s own hardware.
Further WebJobs is a feature of Azure App Service that enables you to run a program or script in the same instance as a web app
And for continuous type web job it runs on all instances that the web app runs on. but you can optionally restrict the WebJob to a single instance.
Related
I just deployed a web app (node.js container and mongo container) using Azure multi-container instances. It's a bit like Docker Compose but works with an Azure specific yaml file: https://learn.microsoft.com/en-us/azure/container-instances/container-instances-multi-container-yaml
Now I see that there is something called "Azure Web App for Containers". This seems to work with a real docker compose yaml file.
Other than the configuration file format, are there any other differences?
Note: I'm talking about Azure container instances, not Azure container services.
Well, azure container instances bill you only for the time container is active, while webapp bill you for the time webapp exists (so all the time). that is one of the biggest differences between those.
But overall, I'd say Azure Web App for Containers is just a shortcut to run containers on existing "stuff". I've recently learned that Azure Web App for Containers offer kubernetes capabilities, so these 2 services evolve in a slightly different directions. Azure Web App for Containers is targeted at long running stuff (always running) while ACI are aimed at scheduled\burstable\short lived workloads (similar to Azure Functions).
Found this link with MS-staff answer.
In summary
Web App for Containers
Recommended if you are already familiar with the Azure Web App environment.
Best if you have one or a few long-running containers/services that are being deployed.
Can use a custom Docker image to run your web app on an application stack that is not already defined in Azure
Azure Container Instances
"Azure Container Instances is a great solution for any scenario that can operate in isolated containers, including simple applications, task automation, and build jobs"
A fast, light-weight and easy way of running containers
Billed for the time your container is active (billing is based on seconds, cores and memory)
Can start containers in Azure in seconds, without the need to provision and manage VMs.
Can also work with Kubernetes through an experimental ACI to Kubernetes connector
Currently, the fastest way to deploy containers on Azure
Based on the Azure docs, " Azure Container Instances guarantees your application is as isolated in a container as it would be in a VM."
Another difference, in addition to the other answer, is that Web App for Containers offers "slots" with which you can run multiple images on the same allocated resources to help increase utilization. As container instances bill per time used, they do not have "slots".
There is a good article about this on Microsoft Learn called: Comparing Container Apps with other Azure container options
Azure Container Instances
Azure Container Instances (ACI) provides a single pod of Hyper-V isolated containers on demand. It can be thought of as a lower-level "building block" option compared to Container Apps. Concepts like scale, load balancing, and certificates are not provided with ACI containers. For example, to scale to five container instances, you create five distinct container instances. Azure Container Apps provide many application-specific concepts on top of containers, including certificates, revisions, scale, and environments. Users often interact with Azure Container Instances through other services. For example, Azure Kubernetes Service can layer orchestration and scale on top of ACI through virtual nodes. If you need a less "opinionated" building block that doesn't align with the scenarios Azure Container Apps is optimizing for, Azure Container Instances is an ideal option.
Azure App Service
Azure App Service provides fully managed hosting for web applications including websites and web APIs. These web applications may be deployed using code or containers. Azure App Service is optimized for web applications. Azure App Service is integrated with other Azure services including Azure Container Apps or Azure Functions. When building web apps, Azure App Service is an ideal option.
Azure Web App for Containers and Azure Web App is the same service and they use an App Service Plan. The only difference is that Publish is set to Docker Container instead of Code by default.
https://azure.microsoft.com/en-us/products/app-service/web/
https://azure.microsoft.com/en-us/products/app-service/containers/#overview
From the article to see other alternatives as well:
There are many options for teams to build and deploy cloud native and containerized applications on Azure.
Azure Container Apps
Azure App Service
Azure Container Instances
Azure Kubernetes Service
Azure Functions
Azure Spring Apps
Azure Red Hat OpenShift
Azure Container Apps
Azure Container Apps enables you to build serverless microservices based on containers. Distinctive features of Container Apps include:
Optimized for running general purpose containers, especially for
applications that span many microservices deployed in containers.
Powered by Kubernetes and open-source technologies like Dapr, KEDA,
and envoy.
Supports Kubernetes-style apps and microservices with features like
service discovery and traffic splitting.
Enables event-driven application architectures by supporting scale
based on traffic and pulling from event sources like queues,
including scale to zero.
Support of long running processes and can run background tasks.
Azure Container Apps doesn't provide direct access to the underlying Kubernetes APIs. If you require access to the Kubernetes APIs and control plane, you should use Azure Kubernetes Service. However, if you would like to build Kubernetes-style applications and don't require direct access to all the native Kubernetes APIs and cluster management, Container Apps provides a fully managed experience based on best-practices. For these reasons, many teams may prefer to start building container microservices with Azure Container Apps.
You can get started building your first container app using the quickstarts.
Azure Kubernetes Service
Azure Kubernetes Service (AKS) provides a fully managed Kubernetes option in Azure. It supports direct access to the Kubernetes API and runs any Kubernetes workload. The full cluster resides in your subscription, with the cluster configurations and operations within your control and responsibility. Teams looking for a fully managed version of Kubernetes in Azure, Azure Kubernetes Service is an ideal option.
Azure Functions
Azure Functions is a serverless Functions-as-a-Service (FaaS) solution. It's optimized for running event-driven applications using the functions programming model. It shares many characteristics with Azure Container Apps around scale and integration with events, but optimized for ephemeral functions deployed as either code or containers. The Azure Functions programming model provides productivity benefits for teams looking to trigger the execution of your functions on events and bind to other data sources. When building FaaS-style functions, Azure Functions is the ideal option. The Azure Functions programming model is available as a base container image, making it portable to other container based compute platforms allowing teams to reuse code as environment requirements change.
Azure Spring Apps
Azure Spring Apps is a platform as a service (PaaS) for Spring developers. If you want to run Spring Boot, Spring Cloud or any other Spring applications on Azure, Azure Spring Apps is an ideal option. The service manages the infrastructure of Spring applications so developers can focus on their code. Azure Spring Apps provides lifecycle management using comprehensive monitoring and diagnostics, configuration management, service discovery, CI/CD integration, blue-green deployments, and more.
Azure Red Hat OpenShift
Azure Red Hat OpenShift is jointly engineered, operated, and supported by Red Hat and Microsoft to provide an integrated product and support experience for running Kubernetes-powered OpenShift. With Azure Red Hat OpenShift, teams can choose their own registry, networking, storage, and CI/CD solutions, or use the built-in solutions for automated source code management, container and application builds, deployments, scaling, health management, and more from OpenShift. If your team or organization is using OpenShift, Azure Red Hat OpenShift is an ideal option.
In a Azure App Service Plan, one can have several slots in addition to the production one.
Do they share resources?
For example, do they each share the same CPU resource or have their own?
In other words, can one slot impact another if it consumes too much (including the production slot)?
Where is this officially documented?
Yes, all deployment slots share resources within the App Service Plan.
As per the official docs,
In App Service, an app runs in an App Service plan. An App Service
plan defines a set of compute resources for a web app to run. These
compute resources are analogous to the server farm in conventional web
hosting.
When you create an App Service plan in a certain region (for example,
West Europe), a set of compute resources is created for that plan in
that region. Whatever apps you put into this App Service plan run on
these compute resources as defined by your App Service plan
For answering your question which is mostly depends on the pricing tier which you have chosen
Shared compute: Free and Shared, the two base tiers, runs an app on
the same Azure VM as other App Service apps, including apps of other
customers. These tiers allocate CPU quotas to each app that runs on
the shared resources, and the resources cannot scale out.
Dedicated compute: The Basic, Standard, Premium, and PremiumV2 tiers
run apps on dedicated Azure VMs. Only apps in the same App Service
plan share the same compute resources. The higher the tier, the more
VM instances are available to you for scale-out.
Isolated: This tier runs dedicated Azure VMs on dedicated Azure
Virtual Networks, which provides network isolation on top of compute
isolation to your apps. It provides the maximum scale-out
capabilities.
Consumption: This tier is only available to function apps. It scales
the functions dynamically depending on workload. For more
information, see Azure Functions hosting plans comparison.
For the slot settings as well, it will share all the resources from the App Service Plan
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.
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.
I am using Azure app service for hosting my web application. I have three slots namely 1. Development, 2.Staging , 3.Production.
I usually go with publishing my website into Development slot and I will swap to Staging and Production.
Whether running additional two slots will affect my production slot performance? And will be billed separately?
As described in the Azure pricing page, specific tiers of Azure App Services contain a number of staging environments (deployment slots). These are included in the app service plan, whether you use them or not. Cost is based on tier and number of instances, not number of slots.
All resources within an App Service plan share the same resources (e.g. if you launch many web apps in the same App Service plan, they all share the same instances). All deployment slots for a given web app reside within the same App Service plan.