When I deliver session on the Azure Hosting services one question that often strike my way is how to choose between Azure App Service(Azure Websites, Cloud Services and Virtual Machines). All three services provides the capability of Azure ecosystem of providing high availability ,Load Balancing and scalability.
As all 3 services of Azure can be used to host the application but it’s very important to understand the offerings of the three to make sure that you are making the right choice. The right choice, of course, will depend on the requirements of a project which can change from project to project.
Let’s focus on three services:
Azure App Service (which, till this April 2015, was called Azure Websites) is a managed platform. This approach that Azure takes benefit of application deployment and administration, at the same time the developer solo needs to direct on app development. Azure App Service supports applications marked by Azure as “Web Apps”, “Mobile Apps”, “API Apps”, and “Logic Apps”.
Azure Cloud Services is a platform that allows developers access to the implied virtual machines and further manages the application container and deployment automatically. This offers a practically more flexible solution than Azure App Service.
Virtual Machines give you full control over application management and deployment. For projects that may require substantial modifications to the technology stack in the future, or for people worried about being locked into a single vendor, the extra work required to launch and maintain Virtual Machines might be worth it.
Virtual Machines gives you full control over the Application Hosting ,Deployment and Environment. In the Applications where we need to handle the environment ourself and if the technology stack can be updated so we need the control over the application and environment.
Azure App Service
So, following the helpful Azure documentation, I successfully deployed my app using the App Service. Things went very smoothly… until I wanted to verify my server configurations and analyze some performance issues. It seems this isn’t possible, since App Service is a managed platform that handles deployment for you. There is no simple way to gain access to the app configuration files once it’s running.
In my case, this wasn’t ideal. I need remote access to the underlying web server, so that I can personally configure server tasks.
Azure Cloud Services
With that in mind, I turned my attention to Azure Cloud Services, which offers a slightly different balance of features. With Cloud Services, you can still enjoy a partially managed platform while, at the same time, maintaining some control over the underlying web servers. This documentation will guide you through deploying your web application using Cloud Services.
What about Virtual Machines? I would say that, if you must have full access to configuration assets and you’re willing to accept the responsibility for managing your whole operation, this might be your best option.
Let’s spend a bit more time weighing these services against each other.
As we said, if you are able to live without control over your webservers, then App Service might be for you. If it is, you’ll be able to enjoy some pretty impressive features, including:
- Instant deployment.
- Vertical scaling, without having to redeploy.
- Support for multiple deployments (like staging and production).
- Automatic OS upgrades for your infrastructure.
- Integration capability with Git.
- Integration capability with MySQL.
Azure App Service doesn’t completely lock you out, by the way. If you do sometimes need to run some background jobs along with your App Services deployment, Azure offers an integrated service called WebJobs. With WebJobs, users trigger custom programs or scripts on demand, continuously, or according to a set schedule. You can upload and run executable files built as cmd, bat, exe (.NET), ps1, sh, php, py, js, and jar with no trouble.
If Azure Cloud Services turns out to be a better fit, you’ll get many of the features of App Service, like support for multiple deployment, automatic OS upgrades, and seamless platform switching. But in addition, you’ll also get Remote Desktop (RDP) access to servers, custom MSI installations, the ability to define and execute start-up tasks, and to listen to Event Tracing for Windows (ETW) events.
And Virtual Machines? Here are some of the tasks that developers may still need to manually manage (Note that with some deployment solutions, these could also be automated):
- Configuration of the application server/framework in the VM.
- Integration with Azure services.
- OS patch management.
- Design and configure the application and infrastructure to handle fluctuating traffic.
- Seamless platform switching (including the ability to move between 32 bit and 64 bit environments).
- Security configuration.
- Identify and apply monitoring strategy for applications.
Finally, here’s a partial list of some fantastic common features supported by all three services:
- Access services like Service Bus, Storage, and SQL Database.
- Host a web or web services tier of a multi-tier architecture.
- Host a middle tier of a multi-tier architecture.
- Support for ASP.NET, classic ASP, Node.js, PHP, and Python.
- Scale out to multiple instances without having to redeploy.
- Support for SSL.
- Visual Studio integration.
- Remote Debugging.
- Network isolation with Azure Virtual Network.
- Integrated Endpoint monitoring.
This diagram illustrates the level of control associated with all three of the Azure services we’ve been discussing:
While all of these services will host applications well, each has its own flavor. Naturally, you should base your choice on your individual business requirements.
This is a first step. There’s obviously much more to learn about these three solutions – and other Azure offerings – and I hope to continue to share my experiences as I learn and grow along with you. I appreciate your comments and encourage you to contribute when the spirit moves you.