WCF History of Distributed Application

WCF 

History of Distributed Application

1.)        Monolithic applications give way to application with components using COM.

2.)        Desktop COM gave way to distributed COM (DCOM).

3.)        DCOM evolved into COM+ and integrated with Microsoft Transaction server.

4.)        .NET components can use enterprise services leverage COM+

5.)        .NET Remoting consists of a client and Remote object hosted on a remote server.

6.)        Enterprise service and .NET Remoting require client ,components and data to be on the same network

7.)        Web services enable us to pass data as XML over internet

a.)SOAP (Simple Object Access Protocol) defines structure of XML Messages Client and Services pass. 

Service Oriented Architecture

1.)        A service is a program that performs a task that you can interact with through well defined messages.

2.)        A service-oriented application consists of loosely couple service that communicate through messages and contracts

a.)        Client does not instantiate the service

3.)        Shift from remotely invoking components to passing messages between services

a.)      Evolution of development model for building distributed applications.

4.)        Service are autonomous

a.)        Build, manage and version service independently(u can build  service independently and client invoke service    independently)

b.)        Change a service without affecting clients as long as clients can communicate send and receiving the same messages.

5.)        Principles of service orientation

a.)        Contracts describe the messages services can send and receive

b.)        Schemes define how the client and service construct the messages they exchange

6.)        Compatibility is policy based

a.)      Service can define the circumstances under which clients can communicates with them.

What Wrong With What We Have?

1.)        Too many ways to crate distributed applications

a.)        Web services(SOA)

b.)        Enterprise Servicesn.Net remoting(not SOA)

2.)        Which should we used and when?

a.) Interoperability

b.) Internet or TCP?

c.)  Internally or Externally.

3.)        How easy to change from one to another?

WCF

1.)        WCF provides unified programming model for building service oriented application.

2.)        One model whether communication is internal or external

3.)        Same service can be exposed over multiple protocols without effort or switching technologies.

WCF Vs Web Services

1.)        Web services generally based on HTTP protocol and XML where as WCF based on not only HTTP but also TCP and other protocols.

2.)        Send messages using format as SOAP in web services and within WCF send messages using formats other than SOAP we can use

a.)        REST(Representational State Transfer)

b.)        POX(Plain Old XML)

3.)        Web service host only within web server where as WCF host on other than web server like java server.

Different way create WCF Sever and WCF Client

WCF Service-Server

1.)        Develop using VS2010 and deploy on IIS

2.)        Deploying on WAS(Windows Activation Service)

3.)        Self host

a.)        Console Application

b.)        Windows Application/WPF Application

c.)        Web Service.

WCF Client

1.)        Using VS2010 “Add Service Reference”

2.)        Using SVCutil.exe

3.)        Custom Program(our own ways)

How TO CREATE WCF SERVICE IN CONSOLE APPLICATION

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.ServiceModel;

using System.ServiceModel.Description;

namespace Myownwcfserver

{

    [ServiceContract]

    public interface IMyownWCFservice

    {

        [OperationContract]

        string SayHello(string name);

        [OperationContract]

        int square(int value);

        [OperationContract]

        int Add(int a, int b);

    }

    public class MyownWCFservice : IMyownWCFservice

    {

        public string SayHello(string name)

        {

            return "Hello " + name;

        }

        public int square(int value)

        {

            return value * value;

        }

        public int Add(int a, int b)

        {

            return a + b;

        }

    }

    class Program

    {

        static void Main(string[] args)

        {

            //create my Host

            ServiceHost MyWCFhost = new ServiceHost(typeof(MyownWCFservice), new Uri[] { new Uri("http://localhost:1059") });

            //cretate end point

            MyWCFhost.AddServiceEndpoint(typeof(IMyownWCFservice),new BasicHttpBinding(),"myownwcfathhtp");

            //add the metadata behaviour for clint understand particular service

            ServiceMetadataBehavior smb=new ServiceMetadataBehavior ();

            smb.HttpGetEnabled=true;

            //add the behaviour to my host

            MyWCFhost.Description.Behaviors.Add(smb);

            //open the host

            MyWCFhost.Open();

            //write some service activation messages

            Console.WriteLine("my own service is running ");

            Console.WriteLine("");

            Console.WriteLine("press any keys to shotdown the service");

            Console.ReadKey();

            //close the host

            MyWCFhost.Close();

        }

    }

}