Programming ASP.NET, 3rd Edition

Global Deployment

In the previous section, we stated that most applications are deployed by copying files to the proper directory. The exception occurs when you wish to use the same assembly in more than one application. In this case, you use global deployment.

There are many scenarios in which you might want to have a common assembly file accessible to multiple applications. A firm might have two different web sites on a server, both providing access to the same database. One web site is free of charge and open to the public but of limited functionality, but the other is fully functional, requiring a paid subscription. Since both sites access the same database, they will have common database query routines. They might also have common login routines. Using the same assembly to contain those common routines will enhance maintainability. Another scenario might be a web-hosting firm that has many web sites running on a server. It might want to offer some functionality to all its client web sites. Encapsulating this functionality in a globally available assembly would make this easy to offer and maintain.

Another consideration is versioning. When assemblies are local to an application, then each application can have its own version of common assemblies. The .NET Framework allows for global assemblies to have multiple versions. Each application making use of the global assembly can either specify the version it wants to use or take the latest version. By specifying the version, an application ...