I have an ASP.NEt Core 3.1 application with Angular 8 frontend. It runs fine when hosted on IIS but as I have moved it onto a new Ubuntu 18 Server with Nginx above Kestrel sometimes the long running background processes stop working (IHostedService). Then the app runs towards accepting new requests so only the background process is stopped.
These processes get files from clients and give immediate responses with a process ids. The clients can query the process state by their id. Everything have been running fine for months now on IIS but the new config must have some limits that kills these processes. I suppose there is some kestrel or nginx option I don't know about and affect processes started by http requests.
What options can I try and where can I get some logs?
I've tried to log everything from .net core but even the most verbose logs are useless here. Nginx logs doesn't contain any info about the stopped process either.
Although the application runs fine hosted on IIS I tried to find catch blocks without any output and added logging into them but still nothing. Are there anything I can add to my application globals to log any exceptions handled or unhandled?
I forgot to say that I use a local Microsoft SQL Server Express both on windows and linux. The linux Sql Server install was done by the official ms docs (as dotnet and nginx config, too). The database is restored from a windows sql server backup. The connection string is the same with multipleresultsets=true. Are there any differences I should aware of?
For anyone getting here in the future: this was caused by a bug in Microsoft.Data.SqlClient, so I had to update it (independently from EF Core 3.1.2) from nuget to the newer 1.1.2 version.
When it stucked I had two threads waiting for each other, both in SqlClient. With Just my code enabled VS debugger stopped at one of my linq queries. The only interesting part was that it never threw any exceptions and there was no deadlock event on the sql server either. It just waited there so all logs were empty.