Run WCF ServiceHost with multiple contracts

You need to implement both services (interfaces) in the same class.

servicehost = new ServiceHost(typeof(WcfEntryPoint));
servicehost.Open(); 

public class WcfEntryPoint : IMyService1, IMyService2
{
    #region IMyService1
    #endregion

    #region IMyService2
    #endregion
}

FYI: I frequently use partial classes to make my host class code easier to read:

// WcfEntryPoint.IMyService1.cs
public partial class WcfEntryPoint : IMyService1
{
    // IMyService1 methods
}

// WcfEntryPoint.IMyService2.cs
public partial class WcfEntryPoint : IMyService2
{
    // IMyService2 methods
}

I'm currently faced with the same problem, and have decided to go with the implementation below. I'm not sure if there are any performance issues with having this many service contracts, but in my final implementation I will probably have about 10 - 15 service contracts, thus about 10-15 ServiceHosts.

I am hosting all my WCF services inside a single Windows Service.

private void PublishWcfEndpoints()
{
    var mappings = new Dictionary<Type, Type>
    {
       {typeof (IAuthenticationService), typeof (AuthenticationService)},
       {typeof(IUserService), typeof(UserService)},
       {typeof(IClientService), typeof(ClientService)}
    };


    foreach (var type in mappings)
    {
        Type contractType = type.Key;
        Type implementationType = type.Value;

        ServiceHost serviceHost = new ServiceHost(implementationType);
        ServiceEndpoint endpoint = serviceHost.AddServiceEndpoint(contractType, ServiceHelper.GetDefaultBinding(),
                                                                  Properties.Settings.Default.ServiceUrl  + "/" + contractType.Name);
        endpoint.Behaviors.Add(new ServerSessionBehavior());

        ServiceDebugBehavior serviceDebugBehaviour =
            serviceHost.Description.Behaviors.Find<ServiceDebugBehavior>();
        serviceDebugBehaviour.IncludeExceptionDetailInFaults = true;

        log.DebugFormat("Published Service endpoint: {0}", Properties.Settings.Default.ServiceUrl);

        serviceHost.Open();
        serviceHosts.Add(serviceHost);
    }

}

Feel free to comment on this type of set up, and if there are any issues with it, especially performance-related.

This answer is a further response to the comment in the accepted answer from chilltemp.

Sam, You really should determine why you need 10-50 contracts and try to find another solution. I looked over Juval Lowy's WCF Coding Standards (found on http://www.idesign.net/) and found the following references:

3 Service Contracts ... 4. Avoid contracts with one member. 5. Strive to have three to five members per service contract. 6. Do not have more than twenty members per service contract. Twelve is probably the practical limit.

He doesn't mention a limit on contract implementations (that I can find) but I can't imagine him viewing 50 contracts on a service as anything resembling a best practice. One solution I have found that works well is to use member sharing for similar functions.

For instance, if you are using the WCF service to perform mathematics on 2 values you might have 4 members on the service side: Add(x,y), Subtract(x,y), Multiply(x,y), Divide(x,y). If you combine these into a more generic member and use an object to pass the needed data you can easily reduce your member count and increase scalability. Example: PeformCalculation(obj) where obj has x, y, and action (add, subtract, multiply, divide) properties.

Hope this helps.