Publishing 2 interface endpoints with common public methods - operation references a message element...that has already been exported

Question

Been trying to add a non secure endpoint to my self hosted service, so basically I have one interface that uses sessions and another one that doesn't. They are both implemented by the same class. Here's part of my server config file:

<service name="PT.DataServices.WCFService.PTDataServices" behaviorConfiguration="dataServiceBehavior">
    <endpoint address="PTDataServices" binding="wsHttpBinding" contract="PT.DataServices.WCFService.IPTDataServices" bindingConfiguration="wsHttpBinding1">
      <identity>
        <dns value="localhost"/>
      </identity>
    </endpoint>

    <endpoint address="PTDataServicesNoSessions" binding="wsHttpBinding" contract="PT.DataServices.WCFService.IPTDataServicesNoSessions" bindingConfiguration="wsHttpBinding2">
      <identity>
        <dns value="localhost"/>
      </identity>
    </endpoint>


    <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>

    <host>
      <baseAddresses>
        <add baseAddress="http://*/PT6/DataServices/"/>
      </baseAddresses>
    </host>
  </service>

Interface without sessions:

[ServiceContract(
    SessionMode = SessionMode.NotAllowed
)]
public interface IPTDataServicesNoSessions
{
    [OperationContract]
    string GetData(int value);

}

Interface with sessions:

[ServiceContract(
    SessionMode=SessionMode.Required
)]
public interface IPTDataServices
{
    [OperationContract(IsInitiating = true, IsTerminating = false)]
    DcUser InitSession(string userCode, string passwordEncrypted, string connectionString);

    [OperationContract(IsInitiating = false, IsTerminating = true)]
    int EndSession();

    [OperationContract(IsInitiating = false, IsTerminating = false)]
    string GetData(int value);
}

Putting :http://localhost/PT6/DataServices/ in a browser returns :

The PT.DataServices.WCFService.IPTDataServicesNoSessions.GetData operation references a message element [http://tempuri.org/:GetData] that has already been exported from the PT.DataServices.WCFService.IPTDataServices.GetData operation.

I don't want to change all clients to use different method names depending on the endpoint that is dynamically being used... how can I tell WCF that it's OK to have the same methods on each of the 2 interfaces?

Answer 1

Figured it out myself. I needed to add the namespace attribute to my interfaces:

[ServiceContract(
    SessionMode=SessionMode.Required,
    Namespace = "PTDataServices/WithSession"
)]

and

[ServiceContract(
    SessionMode = SessionMode.NotAllowed,
    Namespace = "PTDataServices/NoSessions"
)]

This allowed for WCF to avoid method name collisions in the WSDL for the methods that have the same name in both interfaces.