Web services are interesting from several perspectives. From a technological perspective, web services try to solve some problems faced when using tightly coupled technologies such as CORBA and DCOM. These are problems such as getting through firewalls, dealing with the complexities of lower-level transport protocols, and integrating heterogeneous platforms. Web services are also interesting from an organizational and economic perspective, because they open doors for new ways of doing business and integrating systems between organizations. DCOM and CORBA are fine for building enterprise applications with software running on the same platform and in the same closely administered local network. They are not fine, however, for building applications that span platforms, span the Internet, and need to achieve Internet scalability. They were simply not designed for this purpose. This is where web services come in. Web services represent the next logical step in the evolution of component-based distributed technologies. Some key advantages include the following:
Web services are simple: That simplicity means they can be easily supported on a wide range of platforms.
Web services are loosely coupled: The web service may extend its interface and add new methods without affecting the clients as long as it still provides the old methods and parameters.
Web services are stateless: A client makes a request to a web service, the web service returns the result, and the connection is closed. There is no permanent connection. This makes it easy to scale up and out to many clients and use a server farm to serve the web services. The underlying HTTP used by web services is also stateless. Of course, it is possible to provide some state by using additional techniques such as the ones you use in ASP.NET web pages, including cookies. However, these techniques aren’t standardized.
Web services are firewall-friendly: Firewalls can pose a challenge for distributed object technologies. The only thing that almost always gets through firewalls is HTTP traffic on ports 80 and 443. Because web services use HTTP, they can pass through firewalls without explicit configuration.
Web services are simple: That simplicity means they can be easily supported on a wide range of platforms.
Web services are loosely coupled: The web service may extend its interface and add new methods without affecting the clients as long as it still provides the old methods and parameters.
Web services are stateless: A client makes a request to a web service, the web service returns the result, and the connection is closed. There is no permanent connection. This makes it easy to scale up and out to many clients and use a server farm to serve the web services. The underlying HTTP used by web services is also stateless. Of course, it is possible to provide some state by using additional techniques such as the ones you use in ASP.NET web pages, including cookies. However, these techniques aren’t standardized.
Web services are firewall-friendly: Firewalls can pose a challenge for distributed object technologies. The only thing that almost always gets through firewalls is HTTP traffic on ports 80 and 443. Because web services use HTTP, they can pass through firewalls without explicit configuration.
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