Azure App Service cannot access to an externar MSSQL Server

Question

I have a REST App Service that connect to a remote SQL Server host where I have already allowed all IPs from my App Service in the firewall rules.
It was working fine until few hours ago, but now, I´m getting the error: SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible.

When I execute the tcpping command in my App Service console, it usually return a timeout exception in the 1th try but the others are ok:

Ps: I do not have either WAF nor Firewall in in my App Servce

Does anyone else had facing the same issue?

Regards!

Answer 1

Hi @Marcos Roberto Aimola ,

You may have encountered the maximum outbound connections allotted to your app service. You can leverage the Diagnostic and solve problems blade to investigate and dig a little deeper to avoid such issues. Ensure that all outbound connections are leveraging some sort of pooling. There may have been a spike that caused TCP connection issues. You can observe the connection limits, which are based on SKU size, here.

Another option you can consider is utilizing a hybrid connection between your app service and MSSQL. The links provided are guides that hopefully will allow you to zero in on the root cause. If the suggestions provided doesn't please comment below.

Regards,
Ryan