KeepAlive not working

[kartas39]

SqlClient/src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SNI/SNITcpHandle.cs

Line 821 in 699ae37

internal static void SetKeepAliveValues(ref Socket socket)

This method is not called from anywhere. So I think it just doesn't do his stuff.
Please also pay attention that it is wrapped with if NETCOREAPP31_AND_ABOVE, which is defined as:

<PropertyGroup Condition="'$(TargetGroup)' == 'netcoreapp' AND !$(TargetFramework.StartsWith('netcoreapp2.'))">
    <DefineConstants>$(DefineConstants);NETCOREAPP31_AND_ABOVE</DefineConstants>
  </PropertyGroup>

which does not include .Net5 I assume if you build with net5.0

[karinazhou]

Hi @kartas39 ,

I think you are right. This SetKeepAliveValues is not referenced anywhere in the driver. I checked the history of the code and it was initially called in System.Data.SqlClient :
https://github.com/dotnet/corefx/blob/release/3.1/src/System.Data.SqlClient/src/System/Data/SqlClient/SNI/SNITcpHandle.cs#L227

However, when we move from System.Data.SqlClient to Microsoft.Data.SqlClient on Github, this call has been removed. This SetKeepAliveValues method is added back in the driver in PR#395 which will support the TCP KeepAlive feature in the future.

Currently, the driver is not officially built against .NET5.0 but it is compatible when you use it in a .NET5.0 application. For a .net core application, the actual driver's runtime library is from \netcoreapp3.1 folder. The SNITcpHandle is part of the managed SNI implementation which is not used on Windows by default.

Thanks,

[cheenamalhotra]

@kartas39

That was a miss, thanks for reporting it.
The fix has been merged and will be released in future versions.