Error : A transport-level error has occurred when sending the request to the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)

Hello Guys,

I have problem with SQL Server 2008 R2 and .NET Framework 4.0 FULL package.

My problem is :

I develop a .NET application with .NET Framework 4.0. The application connect to Microsoft SQL Server 2008 R2 with update 5. When i deploy application, it work well. But some day ago, the user don't touch on the application about one day. After that user do some thing and it raise error exception.

 A transport-level error has occurred when sending the request to the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)

I guess the connection in Connection Pool lose connect with the sql server engine (Time out, or server restart service, network fails......). But i had check and everything work well.

When i check SPID of my connection in sys.process, I loss. So what and why sql server kill process in SQL Server engine ?

P/s: My application using SQLConnection object and don't close after execute an SQL statement. I would like to reuse connection without close and open again.

Thanks for your help.

Cuong Dang

Cuong