Distributed Transactions in .NET 3.5 - Demo

It was a long October working on a hot release :). Finally got the time to get back to the transaction series. The demo uses a very simple system metaphor where services are decomposed in:

• Data Contracts to transport business entity data across the wire in an optimized fashion.
• Message Contracts to represent the services request and response and to allow service operation changes without breaking contracts.
• Service Contracts to represent the service operations.
• Fault Contracts to represent errors in the services (not explored in this demo).
• Services Web Site.
• Entity Framework Domain Model.
• ASP.NET Web Pages for data consulting.

Transactions are enabled at the WS HTTP binding:

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

The Isolation Level is set to ReadCommited:

[ServiceBehavior(TransactionIsolationLevel = IsolationLevel.ReadCommitted)]
public class CustomersService : ICustomersService
{
...
}

Transactional Operations use the TransactionScope attribute to manage transactions:

[OperationBehavior(TransactionScopeRequired = true)]
public CreateCustomerResponse CreateCustomer(CreateCustomerRequest request)
{
...
}

And the Entity Framework integrates just fine with WCF distributed transactions:

using (DemosEntities entities = new DemosEntities())
{
    // create the entity

    Customer customer = new Customer();

    // translate the data contract to the entity
    
    customer.Name = request.Customer.Name;
    customer.Id = Guid.NewGuid();

    // add it to the set

    entities.AddToCustomerSet(customer);

    // "commit" changes

    entities.SaveChanges();
}

Distributed Transactions Demo v1