High memory consumption of .Net 6 app on Linux

Question

I encountered a very serious problem when switching from Windows to Linux (Ubuntu). The problem is very high memory consumption. I first noticed an increase in memory consumption on Windows when moving from .Net Framework to .Net Core 5. But then this was not much of a problem and was acceptable since the increase was not large. The .Net Framework application consumed approximately 150-200 megabytes and the .Net Core 5 application consumed approximately 250-350 megabytes. But when I switched to Linux, the consumption increased many times over. To make the transition, I switched to .Net 6. After running the application on Linux, I noticed that memory grows over time and does not decrease; with long-term operation of the application, memory consumption can reach 6-8 gigabytes. After doing a memory dump, I noticed that almost 90% was taken up by unmanagement memory. There are about 50 instances of this application running on my server, and they quickly consume all the memory, which leads to application crashes. I have no idea why this is happening, it seems that Garbage collection is not freeing the reserved memory. For information, on Windows under IIS the application worked in 32-bit on Linux in 64-bit.

I tried changing Garbage collection settings such as (DOTNET_GCConserveMemory and DOTNET_gcServer), but it didn't help

Answer 1

The increase in unmanaged memory probably means your code is not properly calling Dispose() on instances that allocate unmanaged memory.

https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/statements/using