The CMS 12 site crash repeatedly when deployed to on-premise Linux server. This error occurs constantly:
Failed to Read cacheKey = 'EP:HashedContentVersion:2015208586' Microsoft.Data.SqlClient.SqlException (0x80131904): Execution Timeout Expired. The timeout period elapsed prior to completion of the operation or the server is not responding. ---> System.ComponentModel.Win32Exception (258): Unknown error 258 at Microsoft.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
Because ASP Net Core on Linux only sets ThreadPool.MaxThreads = 8 by default. The CMS edit mode needs much more than that to load resources and assets.
The issue can be fixed by configuring NetCore runtime as described here: https://docs.microsoft.com/en-us/dotnet/core/runtime-config/threading#maximum-threads.