步骤:
1.把同样的WCF服务，在多个端口上"启动"(即同时运行多个wcf的实例，但每个实例都监听不同的端口)

2.用svcutil.exe生成的代理类，里面有N多构造函数的重载版本，观察一下类似下面的这个版本
 public AstroServiceClient(string endpointConfigurationName) :
            base(endpointConfigurationName)
    {
    }

即传入配置名生与代码类的实例,我们在web.config中的wcf配置节，做如下处理:

<client>
            <endpoint address="http://localhost:8001/Astro/" binding="wsHttpBinding"
                bindingConfiguration="WSHttpBinding_IAstroService" contract="IAstroService"
                name="1">
                <identity>
                    <dns value="localhost" />
                </identity>
            </endpoint>
          <endpoint address="http://localhost:8002/Astro/" binding="wsHttpBinding"
                bindingConfiguration="WSHttpBinding_IAstroService" contract="IAstroService"
                name="2">
            <identity>
              <dns value="localhost" />
            </identity>
          </endpoint>
          <endpoint address="http://localhost:8003/Astro/" binding="wsHttpBinding"
                bindingConfiguration="WSHttpBinding_IAstroService" contract="IAstroService"
                name="3">
            <identity>
              <dns value="localhost" />
            </identity>
          </endpoint>
        </client>

即对应多个wcf服务端的实例，配置多个name的endpoint节点

3.修改客户端的调用代码

把原来类似这样的代码:
using (AstroServiceClient _client = new AstroServiceClient())

改成

using (AstroServiceClient _client = new AstroServiceClient(new Random().Next(1, 4).ToString()))

即客户端随机从多个wcf服务端的host中挑一个，生成代码类实例

大功告成，说白了就是把一个wcf的host分身成了3个，并且客户端随机调用3者之一。