New Features in WCF 4.5 - Part 5

“A ChannelFactory basically creates a Channel for WCF clients to communicate with WCF service endpoint“.

In one of my previous WCF Interview Questions Tutorial Series, we discussed about the difference between using ChannelFactory and Windows Communication Foundation Proxy. Here in this WCF Tutorial, we are going to discuss about a new feature of Windows Communication Foundation v 4.5 i.e. “ChannelFactory Cache“. WCF 4.5 now support for caching Channel Factories to reduce overhead associated while creating a new ChannelFactory instance.

Before moving forward, let’s first summarize that what we have covered so far in this WCF 4.5 Tutorial Series.

New Features in WCF 4.5 – Part 1
- Simplified Generated Configuration
- Validating WCF Configuration
New Features in WCF 4.5 – Part 2
- Single WSDL file
- Tooltip and Intellisense Support
New Features in WCF 4.5 – Part 3
- ASP.NET Compatibility Mode default change
- BasicHttpsBinding
New Features in WCF 4.5 – Part 4
- Task-based Programming Model

Using ChannelFactory is a good option, if we have control over Client as well as Server because in case of ChannelFactory, we have local interfaces (WCF Contract) on client to describe our WCF service.

Following is a simple code for creating a ChannelFactory:

static void Main(string[] args)
{
BasicHttpBinding cacheTestBinding = new BasicHttpBinding();
EndpointAddress cacheTestEndpoint = new
EndpointAddress(“http://localhost:XXX/CacheTestService.svc”);
ChannelFactory cacheTestChannelFac = new
ChannelFactory(cacheTestBinding, cacheTestEndpoint);

var objChannel = cacheTestChannelFac.CreateChannel();

Console.WriteLine(objChannel.MethodA());

objChannel.Close();
}

Although using ChannelFactory in Windows Communication Foundation is a nice approach but there is resource overhead involved in creating ChannelFactory instance. To avoid this overhead and boost performance, WCF developers were using some custom caching approach for ChannelFactory.

Now with WCF 4.5, built-in support available for ChannelFactory Cache through CacheSetting property of ClientBase<T> class. Possible values of CacheSetting property are:

System.ServiceModel.CacheSetting.AlwaysOn
System.ServiceModel.CacheSetting.Default
System.ServiceModel.CacheSetting.AlwaysOff

CacheSetting.AlwaysOn:
Caching is always ON meaning all instances of ClientBase within same app-domain will be using sameChannelFactory.

ClientBase<ICacheTestService>.CacheSetting = System.ServiceModel.CacheSetting.AlwaysOn;

CacheSetting.AlwaysDefault:

With default means that only instances of ClientBasecreated from configuration file endpoint will participate in caching. Others created programmatically will not participate. Also condition of same app-domain is also applicable here.

ClientBase<ICacheTestService>.CacheSetting = System.ServiceModel.CacheSetting.Default;

CacheSetting.AlwaysOff:
No caching for all instances of ClientBase<TChannel>.

ClientBase<ICacheTestService>.CacheSetting = System.ServiceModel.CacheSetting.AlwaysOff;

Undoubtedly, this new feature in Windows Communication Foundation v4.5 is really helpful for WCF developers to manage support for caching ChannelFactory instances.

New Features in WCF 4.5 – Part 5

Other Related Articles:

Top 10 Interview Questions and Answers Series: