TransactionScope promoting to MSDTC although I am using the same connection string

Question

I have two repositories that point to the same SQL Server 2008 R2 (10.50.2550.0) database. One repository is based on Entity Framework, the other uses regular SqlConnection. I need to perform an operation that involves both, so I have used a TransactionScope to keep them in the same transaction:

using (TransactionScope scope = new TransactionScope(TransactionScopeOption.RequiresNew, new TransactionOptions() { IsolationLevel = IsolationLevel.RepeatableRead }))
{
   _repoA.DoStuff();
   _repoB.DoStuff();
}

Since I use the same connection string in both:

"Data Source=(local);Initial Catalog=mydb;User Id=myid;Password=mypass;Asynchronous Processing=true"

I was expecting that SQL Server 2008 R2 could use multiple connections without scalating. Unfortunately I get an exception saying:

System.Data.SqlClient.SqlException occurred Message=MSDTC on server 'MyComputer' is unavailable. Source=.Net SqlClient Data Provider
ErrorCode=-2146232060 Class=16 LineNumber=1 Number=8501
Procedure="" Server=(local) State=2 StackTrace: at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)

What could be the problem?

Cheers.

Answer 1

Ok, I found why. Entity Framework is modifying my connection string to:

"Data Source=(local);Initial Catalog=mydb;User Id=myid;Password=mypass;Asynchronous Processing=true;Application Name=EntityFrameworkMUE"

And that is causing the promotion to MSDTC!

In order to avoid this, I have set up my own "Application Name" in the connection string and it works now.

Cheers.