What is WCF Service?
When your business relies on a service-oriented architecture, you must make sure that your services are robust. The most important driver behind the robustness of your application is where/how you host your service. You must ask yourself several questions when thinking about hosting services: What are the availability requirements of my services? How am I going to manage and deploy my services? Do I need to support older versions of my services?
Introduction to WCF (Windows Communication Foundation)
Learning how to cover these business requirements is essential to developing successful services. You have to host services on your own host. Windows Communication Foundation (WCF) doesn't come with its own host, but instead comes with a class called
ServiceHost that allows you to host WCF services in your own application easily. You don't have to think about any of the network transport specifics to be able to make sure that your services are reachable. It's a matter of configuring your services' endpoints either programmatically or declaratively, and calling the Open method of ServiceHost. All of the generic functionality regarding bindings, channels, dispatchers, and listeners is integrated into ServiceHostBase
and ServiceHost. This means that the responsibility of the application that you use to host your service, the application where ServiceHost is running, is significantly less than you would expect up front.
Exploring Your Hosting Options
On the Microsoft .NET platform, you have several types of managed Windows applications that you can create with Microsoft Visual Studio.NET:
|
|
- WinForms applications
- Console applications
- Windows services
- Web applications (ASP.NET) hosted on Internet Information Services (IIS)
- WCF services inside IIS 7.0 and WAS on Windows Vista or Windows Server code
name "Longhorn"
|
If you look through the project templates that come with Microsoft Visual Studio 2005, you will find other options available at your disposal. For obvious reasons, we don't consider any of the other templates to be viable options to use in the services world. It is worth noting, however, that WCF doesn't block you from running your service in any other type of application as long as it provides you with a .NET application domain. (If you don't know the concepts behind a .NET application domain, please refer to the "Understanding .NET Application Domains" section that follows.) It all comes down to the requirements you have for your host. To summarize the options, think about the following three generic categories of hosts for your WCF services:
|
|
- Self-hosting in any managed .NET application
- Hosting in a Windows service
- Hosting in different versions of IIS
|