how to handle transactions in WCF services

Question

I have a WPF application and In button click event I am calling WCF service for handling transaction in it. After one transaction complete I am throwing exception. To see whether transaction will rollback or not. But even I got error still transaction got completed it is not aborted in database.

UI Button event:

private void button1_Click(object sender, RoutedEventArgs e)
{
    binding = new WSHttpBinding();
    endpoint = new EndpointAddress("http://localhost:6144/EmployeeService.svc/EmployeeService");

    ChannelFactory<IEmployeeService> cf = new ChannelFactory<IEmployeeService>(binding, endpoint);
    IEmployeeService obj = cf.CreateChannel();

    using (TransactionScope ts = new TransactionScope(TransactionScopeOption.RequiresNew))
    {
        try
        {
            obj.UpdateProductData(201, 10);
            throw new Exception("Wrong");
            obj.UpdateProductData(202, 15);
            ts.Complete();
        }
        catch (Exception ex)
        {
            ts.Dispose();                          
        }
    }
}

In app.config i already given "transactionFlow="true".

WCF Service:

[OperationBehavior(TransactionScopeRequired=true,TransactionAutoComplete=true)]
public bool UpdateProductData(int ProdId, int Amount)
{
    DALClass objDALProd = new DALClass();
    return objDALProd.UpdateProductData(ProdId, Amount);
}

DALClass:

public bool UpdateProductData(int prodID,int Amount)
{
    try
    {
        objComd.Connection = objConn;
        objConn.Open();
        objComd.CommandText = "UpdateEmployeeData";
        objComd.CommandType = CommandType.StoredProcedure;
        objParam = new SqlParameter("@ProductId", prodID);
        objComd.Parameters.Add(objParam);
        objParam = new SqlParameter("@Amount", Amount);
        objComd.Parameters.Add(objParam);

        objComd.ExecuteNonQuery();
        objConn.Close();
    }
    catch(Exception ex)
    {
        throw new FaultException("Database Error");
    }
    return true;
}

Please let me know where my mistake is. Transaction is not rolled back, even when I am raising exception first transaction is not rolled back.

Note: you don't need the `try/catch/ts.Dispose()` part. That's what the `using` block itself is for. Worse yet, you swallow all exceptions there. — Christian.K, Sep 18 '12 at 10:33

score 2 · Answer 1 · answered Sep 18 '12 at 10:07

2

Have you defined the transaction flow on your WCF contract?

[OperationContract]
[TransactionFlow(TransactionFlowOption.Mandatory)]

Have you defined the transaction flow on both the client and server config?

<wsHttpBinding>
<binding name="transactionalWsatHttpBinding"
         transactionFlow="true" />
</wsHttpBinding>

answered Sep 18 '12 at 10:07

Shiraz Bhaiji

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Below is the code added for the WCF Contract But no use... please let me know if there is any other way : [OperationBehavior(TransactionScopeRequired=true,TransactionAutoComplete=true)] public bool UpdateProductData(int ProdId, int Amount) { DALClass objDALProd = new DALClass(); return objDALProd.UpdateProductData(ProdId, Amount); } – user1661171 Sep 18 '12 at 15:16
It looks like you put the attribute on the class not the interface – Shiraz Bhaiji Sep 18 '12 at 18:50

score 2 · Answer 2 · edited May 23 '17 at 12:16

You need to enable transactions in both the client and service binding by setting WSHttpBindingBase.TransactionFlow=true.
You can check on the service being called if the transaction really is flowing by checking if Transaction.Current.TransactionInformation.DistributedIdentifier is non-zero. If its zero, then the flow is not working and rollback won't happed.

See the answer to How can I implement WCF Transaction support on custom class using CoreService? for more details and links.

Dan Ling · Answer 3 · 2013-10-15T14:41:30.963

Your client side code looks fine to me, but on the server side, there are a total of 3 attributes you need to get this to work.

Service Interface needs [TransactionFlow] on the operation.

[ServiceContract]
public interface IService
{
  [OperationContract]
  [TransactionFlow(TransactionFlowOption.Allowed)]
  bool UpdateProductData(int ProdId, int Amount);
}

Service Class needs [ServiceBehavior] on the class and [OperationBehavior] on the method:

[ServiceBehavior(TransactionIsolationLevel = IsolationLevel.ReadUncommitted)]
public class Service : IService
{
  [OperationBehavior(TransactionScopeRequired=true,TransactionAutoComplete=true)]
  public bool UpdateProductData(int ProdId, int Amount)
  {
    DALClass objDALProd = new DALClass();
    return objDALProd.UpdateProductData(ProdId, Amount);
  }
}

Also note that these attributes are only one way to do achieve this - you can also do all of this in the config file if desired. Config files make it easier to apply these settings to multiple services in one shot.

how to handle transactions in WCF services

3 Answers3