using TransactionScope : System.Transactions.Trans

Question

We're trying to do indirect nesting transaction using the code below, .NET 3.5 ,& SQL Server 2005.

MSDN says that when using TransactionScope, a transaction is escalated whenever application opens a second connection (even to the same database) within the Transaction.

void RootMethod()
{
   using(TransactionScope scope = new TransactionScope())
   {
      /* Perform transactional work here */
      FirstMethod();
      SecondMethod();
      scope.Complete();
   }
 }

void FirstMethod()
{
    using(TransactionScope scope = new TransactionScope(TransactionScopeOption.Required))
   {
     using (SqlConnection conn1 = new SqlConnection("Data Source=(local);Initial Catalog=Northwind;Integrated Security=SSPI")) 
       {
     string insertString = @"
             insert into Categories
             (CategoryName, Description)
             values ('Laptop1', 'Model001')";
         conn1.Open();
         SqlCommand cmd = new SqlCommand(insertString, conn1);
         cmd.ExecuteNonQuery();
        }
      scope.Complete();
    }
 }

 void SecondMethod()
 {
    using(TransactionScope scope = new TransactionScope(TransactionScopeOption.Required))
   {
       using (SqlConnection conn2 = new SqlConnection("Data Source=(local);Initial Catalog=Northwind;Integrated Security=SSPI")) 
       {
     string insertString = @"
             insert into Categories
             (CategoryName, Description)
             values ('Laptop2', 'Model002')";

         conn2.Open();  //Looks like transactionabortedException is happening here
         SqlCommand cmd = new SqlCommand(insertString, conn2);
         cmd.ExecuteNonQuery();
        }
        scope.Complete();
    }
  }

Occasionally, the transaction fails that, is not promoting to DTC, and we are getting the following as the inner stack trace,

System.Transactions.TransactionAbortedException: The transaction has aborted. ---> 
System.Transactions.TransactionPromotionException: Failure while attempting to promote transaction. ---> 
System.InvalidOperationException: The requested operation cannot be completed because the connection has been broken.     
at System.Data.SqlClient.SqlInternalConnectionTds.ExecuteTransaction(TransactionRequest transactionRequest, String name, IsolationLevel iso, SqlInternalTransaction internalTransaction, Boolean isDelegateControlRequest)     
at System.Data.SqlClient.SqlDelegatedTransaction.Promote()     --- End of inner exception stack trace ---     
at System.Data.SqlClient.SqlDelegatedTransaction.Promote()     
at System.Transactions.TransactionStatePSPEOperation.PSPEPromote(InternalTransaction tx)     
at System.Transactions.TransactionStateDelegatedBase.EnterState(InternalTransaction tx)     
--- End of inner exception stack trace ---     
at System.Transactions.TransactionStateAborted.CreateAbortingClone(InternalTransaction tx)     
at System.Transactions.DependentTransaction..ctor(IsolationLevel isoLevel, InternalTransaction internalTransaction, Boolean blocking)     
at System.Transactions.Transaction.DependentClone(DependentCloneOption cloneOption)     
at System.Transactions.TransactionScope.SetCurrent(Transaction newCurrent)     
at System.Transactions.TransactionScope.PushScope()     
at System.Transactions.TransactionScope..ctor(TransactionScopeOption scopeOption)    

Can anyone please help me figuring out the reason for this failure?

Answer 1

If you use TransactionScope and you:

• open more than one connection to a database and
• are connecting to a SQL Server 2005 server

the transaction will be escalated to DTC. Check this other SO question: TransactionScope automatically escalating to MSDTC on some machines?

The solution is either:

• Use SQL Server 2008 or

• Use SqlTransaction instead of TransactionScope just like the former answer suggests:

  using (var conn = new SqlConnection(connectionString))
  {  
      using (var tx = conn.BeginTransaction())
      {
          FirstMethod(conn);
          SecondMethod(conn);
          tx.Commit();
      }
  }
  

Answer 2

i can propose to you a better way to achieve your goal. there should be a single transaction for 2 DB call per connection.

it should be like

using (SqlConnection conn1 = new SqlConnection("Data Source=(local);Initial Catalog=Northwind;Integrated Security=SSPI"))
{ 
    using (conn1.BeginTransaction()
    {
        try
        {
            FirstMethod(Conn1);
            SecondMethod(Conn2);
        }
        catch()
        {
        }
    }
}