C# – WCF client proxy initialization

cchannelwcf

I am consuming a WCF service and created its proxy using the VS 2008 service reference.

I am looking for the best pattern to call WCF service method

Should I create the client proxy instance every time I call the service method and close the client as soon as I am done with that? When I profiled my client application, I could see that it is taking a lot of time to get the Channel while initializing the proxy client
Should I use a Singleton pattern for the client proxy so that I can use the only once instance and get rid of the re-initializing overhead? Is there any hidden problem with this approach?

I am using the .Net framework 3.5 SP1, basicHttp binding with little customization.

Best Answer

It depends ;-)

If you have a sequence in your app that requires several calls after one another, you could hang on to the proxy client and keep using it to make further calls. Be warned though to check for the "faulted" state - if an error happens on the server, the channel between the client proxy and the server might "fault" and thus your client proxy becomes unusable.

Also - the expensive part is the creation of the ChannelFactory<T> - you could try to separate these two steps out when you create your client proyx in code:

ChannelFactory<IYourService> factory = new ChannelFactory<IYourService>();

Hang on to that channel factory, e.g. cache it somewhere

The second step should be much less intensive in terms of time and horsepower:

IYourService client = factory.CreateChannel();

You could do this step before every call (or call sequence) and shouldn't get bad performance out of that, really.

I would strongly recommend to avoid singletons whenever possible - it's like opening a can of worms, don't do it unless you absolutely, positively have to (e.g. to manage access to a single resource that's only available for one caller at a time).

Marc

Related Solutions

Wcf – How to set an HTTP Proxy (WebProxy) on a WCF client-side Service proxy

It makes sense that there is no Proxy property on the WCF proxy, because not all WCF proxies use HTTP for communication. After further review, I found that it is possible to set the proxy in WCF programmatically, if the WCF proxy uses an HTTP binding. I am documenting it here in case someone else needs it. To set the HTTP Proxy in code for a WCF client, do this:

// instantiate a proxy for the service
var svc= new ServiceClient();
// get the HTTP binding
var b = svc.Endpoint.Binding as System.ServiceModel.BasicHttpBinding;
b.ProxyAddress = new Uri("http://127.0.0.1:8888");
b.BypassProxyOnLocal = false;
b.UseDefaultWebProxy = false;

And to set the endpoint address - where to reach the server - in code, you would do something like this:

var e = svc.Endpoint;
e.Address = new System.ServiceModel.EndpointAddress(
    "http://remoteserver:5555/WcfXmlElement");

C# – WCF client connection issue

The connection will be closed when the underlying channel closes - by default, the BasicHttpBinding sends a connection HTTP header in messages with a Keep-Alive value, which enables clients to establish persistent connections to the services that support them.

This doesn't mean an instance of the service is kept alive, just the connection to the web server, if the web server supports it.

If you want the connection to close after every call then you can turn it off on the server side by defining a custom binding thus

<services> 
 <service>
  <endpoint address=""
        binding="customBinding"
        bindingConfiguration="HttpBinding" 
        contract="IContract" />
 </service>
</services>

<bindings>
 <customBinding>
   <binding name="HttpBinding" keepAliveEnabled="False"/>
 </customBinding>
</bindings>

Connections will close depending on how long your proxy hangs around for, and the generated proxy will reopen it again if it needs to.

Best Answer

Related Solutions

Wcf – How to set an HTTP Proxy (WebProxy) on a WCF client-side Service proxy

C# – WCF client connection issue

Related Topic