WCF - contracts versioning (by example)

Question

This should be easy for someone familiar with the best practices of versioning service/data contracts. I want to make sure that I will use this versioning in the correct way.

So, let's say we have a service contract:

[ServiceContract(Namespace="http://api.x.com/Svc1")]
public interface IService1
{
   [OperationContract(Name = "AddCustomer")]
   bool AddCustomer(DTOCustomer1 customer);
}

and data contract:

[DataContract(Name="Customer", Namespace="http://api.x.com/Svc1/2011/01/DTO")]
public class DTOCustomer1
{
   [DataMember(Name="Name")]
   public string Name { ... }
}

if I really need to change the latter into something else: (the following is just example)

[DataContract(Name="Customer", Namespace="http://api.x.com/Svc1/2012/01/DTO")]
public class DTOCustomer2
{
   [DataMember(Name="Name")]
   public string Name { ... }

   [DataMember(Name="Address")]
   public DTOAddress Address { ... }
}

...then how shall I use DTOCustomer2 instead of DTOCustomer1 from the service so that old and new clients will be compliant? What is recommended in this case? Will my service contract change? AFAIK I won't need to change the service contract. How will the service contract look like? Do I need a new endpoint? Do I need a new operation contract making use of the new data contract?

EDIT1: Simply changing

bool AddCustomer(DTOCustomer1 customer);

into

bool AddCustomer(DTOCustomer2 customer);

will do?

EDIT2: Answer to EDIT1 is No, since DTOCustomer2 has different namespace, but it might work if it has the same namespace. Still I don't know what is the best thing here and expect somebody to come up with a good answer.

Thank you in advance!

Answer 1

I ended up answering to this question with the help of another question here: WCF - handle versioning