WCF客户端，是否保留引用？

Question

Consider the following scenario:

There is a windows service hosting a WCF service.

The WCF service provides an interface between clients and an AppFabric server located on a physically different machine. It retreievs objects, does calculations on it and returns the best one.

20-30 clients can connect to the service at the same time which is not that much.

What would be better, create an instance every time a query is done on the service or have the client object as a member and call functions. Creating an instance litters everything with try finally block which I dont like but what about the client connection, what are the disadvantages? Can the host be restarted and have clients still work? What is the usual/preferred way to do this?

try
{
  PreOrderService.PreorderServiceClient proxy = new   PreOrderService.PreorderServiceClient("netTcpPreorderService");

  List<PreOrder> preOrders = proxy.FindWallet(preOrder.WalletId);
}
finally
{
  if (proxy.State != CommunicationState.Faulted)
    proxy.Close();
}

Answer 1

I prefer to do the following:

proxy = newServiceReference1.ServiceDataContractTestClient(); 
try
{ 
    proxy.MetodThrowsException();
    proxy.Close(); 
} 
catch
{ 
    proxy.Abort(); 
    throw; // Or handle exception
}

This does not care if the server connection has been lost, and does not throw a CommunicationObjectFaultedException when proxy.MetodThrowsException() breaks the server.

If you find that it reduces readability, then wrap it in a separate method.