I am aware it is on the cloud, but which OS and web server version is Azure App Service running on?

CodePudding user response：

It primarily depends on the runtime stack.

• .NET, Java, Node can run on both, Linux and Windows and you can choose which OS you want.
• PHP, Python and Ruby run on Linux only.

The webserver used to serve requests also depend on the runtime stack (assuming here we run the App Service as "Code" and not as "Container"):

• For .NET Core on Linux Kestrel is used, IIS on Windows.
• For Python, gunicorn is used by default.
• For Node on Linux pm2 is used, on Windows it's IISNode.

Further information: https://docs.microsoft.com/en-us/azure/app-service/configure-language-dotnet-framework

CodePudding user response：

All Azure Web Apps (as well as Mobile App/Services, WebJobs and Functions) run in a secure environment called a sandbox. Each app runs inside its own sandbox, isolating its execution from other instances on the same machine as well as providing an additional degree of security and privacy which would otherwise not be available. The sandbox mechanism aims to ensure that each app running on a machine will have a minimum guaranteed level of service; furthermore, the runtime limits enforced by the sandbox protects apps from being adversely affected by other resource-intensive apps which may be running on the same machine.

https://github.com/projectkudu/kudu/wiki/Azure-Web-App-sandbox