I just started using IIS in a container on Azure App Service.
I get 503.0 errors on a windows container (IIS):
HTTP Error 503.0 - Service Unavailable
The service is unavailable.
Most likely causes:
- An invalid identity in the application pool could cause this error.
- The application pool is no longer running because of configuration or reaching application failure limits.
- The concurrent application request limit was reached.
Even after an App Service restart, the problem persists. So I deleted and then recreated the service app.
I see these errors only on an environment with more load but not on a test env.
Do you have any idea to help me avoid these 503.0 errors? Is it possible to stop one container among others in App Service?
My problem was ultimately due to out of memory. I increased the memory limit used by each container in the App Service (parameter: WEBSITE_MEMORY_LIMIT_MB).
I did not understand at the beginning why I was receiving the out-of-memory error despite the app service graphs showing use of 40%. This is because the node which hosts the Windows containers already consumes around 50% of the physical memory, but I think it lacks visibility on memory usage with Windows containers.
Support says:
On Azure App Service Windows container we do not have memory analysis detector in Diagnose and solve problems blade.