High netcore memory usage compared to windows (From an VS Template starter app)

[stusklinar]

Description

We've noticed issues with Azure App Services (linux) using more memory than we'd expect for linux apps vs Windows

To test this and take everything out of the equation - I used Visual Studio to create a new Web Api (Weather Forecast), and ran it locally using Windows, deployed it to a Linux App Service and ran it via WSL.

The Windows run ran as expected, using around 20mb to run the app, however, out of the box with no adjustments, the Linux version needs around 170mb to just exist. All good and well, until we can only fit a few app within an app service on Azure.

This makes the move to Linux not viable for us, and perhaps others as the machines required to run simple APIs is too much compared to Windows.

Configuration

Standard out of the box .net 6 or 7

Data

HTOP Before running the app

HTOP After starting (In release mode)

Analysis

Console apps seem to also have this issue, with 8mb (Windows) compared to 100mb (Linux)

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Issue Details

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### Description We've noticed issues with Azure App Services (linux) using more memory than we'd expect for linux apps vs Windows To test this and take everything out of the equation - I used Visual Studio to create a new Web Api (Weather Forecast), and ran it locally using Windows, deployed it to a Linux App Service and ran it via WSL. The Windows run ran as expected, using around 20mb to run the app, however, out of the box with no adjustments, the Linux version needs around 170mb to just exist. All good and well, until we can only fit a few app within an app service on Azure. This makes the move to Linux not viable for us, and perhaps others as the machines required to run simple APIs is too much compared to Windows. ### Configuration Standard out of the box .net 6 or 7 ### Data HTOP Before running the app HTOP After starting (In release mode) ### Analysis Console apps seem to also have this issue, with 8mb (Windows) compared to 100mb (Linux)

Author:	stusklinar
Assignees:	-
Labels:	`tenet-performance`, `area-GC-coreclr`, `untriaged`
Milestone:	-

[mangod9]

Hi @stusklinar, do you observe this behavior with a vanilla .NET app, or is it specific to a particular app? Also are you running in a memory constrained container environment?

[stusklinar]

This is a vanilla app, with no changes, in a normal app service

[MattMinke]

We are seeing this behavior as well in Azure where a App Service with Windows OS uses significantly less memory than an App Service running Linux OS.

Others have documented this issue on stack overflow as well.

• https://stackoverflow.com/questions/67771510/moving-to-azure-linux-for-my-web-app-made-the-memory-usage-jump-from-50mb-to-300
• https://devops.stackexchange.com/questions/16975/huge-differences-in-windows-vs-linux-app-service-memory-usage/18050#18050

[mangod9]

I wonder whether this is just a function of available memory on the running container? Do you observe the same behavior if you force to run with WKS GC?