Windows Azure: Service Bus Relay

Service Host:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.ServiceModel;

namespace Test.WCF.ServiceBus.Host.Service
{
    [ServiceContract(Namespace = "urn:ps")]
    interface IProblemSolver
    {
        [OperationContract]
        int AddNumbers(int a, int b);
    }

    interface IProblemSolverChannel : IProblemSolver, IClientChannel { }
}

IProblemSolver.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Test.WCF.ServiceBus.Host.Service
{
    class ProblemSolver : IProblemSolver
    {
        public int AddNumbers(int a, int b)
        {
            return a + b;
        }
    }
}

ProblemSolver.cs

using Microsoft.ServiceBus;
using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using System.Text;
using System.Threading.Tasks;
using Test.WCF.ServiceBus.Host.Service;

namespace Test.WCF.ServiceBus.Host
{
    class Program
    {
        static void Main(string[] args)
        {
            ServiceHost sh = new ServiceHost(typeof(ProblemSolver));

            sh.AddServiceEndpoint(
               typeof(IProblemSolver), new NetTcpBinding(),
               "net.tcp://localhost:9358/***Relay Name***");

            sh.AddServiceEndpoint(
               typeof(IProblemSolver), new NetTcpRelayBinding(),
               ServiceBusEnvironment.CreateServiceUri("sb", "***Service Bus Name***", "***Relay Name***"))
                .Behaviors.Add(new TransportClientEndpointBehavior
                {
                    TokenProvider = TokenProvider.CreateSharedSecretTokenProvider("owner", "***Service Bus Token***")
                });

            sh.Open();

            Console.WriteLine("Press ENTER to close");
            Console.ReadLine();

            sh.Close();
        }
    }
}

Program.cs

 

Service Client:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.ServiceModel;

namespace Test.WCF.ServiceBus.Client
{
    [ServiceContract(Namespace = "urn:ps")]
    interface IProblemSolver
    {
        [OperationContract]
        int AddNumbers(int a, int b);
    }

    interface IProblemSolverChannel : IProblemSolver, IClientChannel { }
}

IProblemSolver.cs

using Microsoft.ServiceBus;
using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using System.Text;
using System.Threading.Tasks;

namespace Test.WCF.ServiceBus.Client
{
    class Program
    {
        public static ChannelFactory<IMediaServicesManagementServiceChannel> testCF=null;
        static void Main(string[] args)
        {

            Retry(
                () =>
                {
                    bool flag = false;
                    var cf = new ChannelFactory<IMediaServicesManagementServiceChannel>(
                                   new NetTcpRelayBinding(),
                                   new EndpointAddress(ServiceBusEnvironment.CreateServiceUri("sb", "***Service Bus Name***", "***Relay Name***")));

                    cf.Endpoint.Behaviors.Add(new TransportClientEndpointBehavior { TokenProvider = TokenProvider.CreateSharedSecretTokenProvider("owner", "***Service Bus Token***") });

         
                    var ch1 = cf.CreateChannel();

                    try
                    {
                        Console.WriteLine(ch1.AddNumbers(3, 4));
                        flag = true;
                    }
                    catch
                    {
                        ch1.Abort();
                        flag = false;
                    }
                    finally
                    {
                        if (ch1 != null)
                        {
                            ch1.Close();
                        }
                    }
                    return flag;
                },
                5);
            


            Console.WriteLine("Press ENTER to close");
            Console.ReadLine();
        }

        public static void Retry(Func<bool> task, int times)
        {
            bool flag = false;
            
            for (int i = 0; i < times; i++ )
            {
                flag = task();
                
                if(flag==true)
                {
                    break;
                }
            }
        }


    }
}

Program.cs

這裏在client端加入了Retry的邏輯以用於因爲網絡不穩定或其餘緣由形成的Host Service Faulted State的情形。

同時要注意，WCF建立的Channel是Fault State時，在調用.Close()以前, 要先調用.Abort().

Reference Links:

http://jeffbarnes.net/blog/post/2007/04/24/wcf-your-proxy-can-only-fault-once.aspx

http://blog.tallan.com/2009/05/06/recover-from-a-wcf-service-fault/