The .NET Framework types are the foundation on which developers build .NET applications, components, and controls. The .NET Framework types use a hierarchical dot naming scheme. This scheme groups related types into namespaces so that developers can more easily search and reference them. The first part of the full name (i.e., up to the rightmost dot) is the namespace name. The last part of the name is the type name. For example,
System.Web.SessionState
shows the SessionState type, which belongs to the System.Web namespace. Developers can use the types in System.Web to manipulate collections of objects. The System.Web namespace provides support for Web server and client management, communication, and design. It also provides core infrastructure for ASP.NET, including Web Forms support. Hundreds, if not thousands, of namespaces are available to .NET application developers.
The System namespace is the root namespace for fundamental data types in the .NET Framework. This namespace includes classes that represent the base data types that all applications use: Object (the root of the inheritance hierarchy), Byte, Char, Array, Int32, String, and so on. Many of these types correspond to the primitive data types (e.g., Boolean types, decimal types) that a .NET programming language uses. For example, in Visual Basic .NET, you use the code
DIM testString as String
to declare a variable as a String primitive data type.
Now you have a good understanding of the .NET Framework and the components it encompasses. Let's take a look at installing the .NET Framework and the resulting implications.
Installation Requirements
The .NET Framework has both client and server installation requirements.
Client-side installation requirements. On the client side, you can install the .NET Framework on Windows XP Home Edition, Windows NT Workstation 4.0 , and Windows 98. The .NET Framework requires a 90MHz Pentium processor or the minimum speed that the OS requires, whichever is greater. The .NET Framework also requires 32MB of RAM, but Microsoft recommends 96MB of RAM.
Server-side installation requirements. On the server side, the .NET Framework requires one of these OSs:
- Windows 2000 Server, Win2K Advanced Server, Win2K Professional, or Win2K Datacenter Serverall with Service Pack 2 (SP2)
- Windows XP Professional Edition
Microsoft will include the .NET Framework with the entire Windows .NET server family, which is due to ship in late 2002. The .NET Framework requires a 133MHz Pentium processor or the minimum speed that the server OS requires, whichever is greater. The .NET Framework also requires 128MB of RAM, but Microsoft recommends 256MB of RAM.
Server-side .NET Framework installation has a few additional requirements. First, to use the Microsoft SQL Server .NET data provider (and your developers most likely will use it), you must install Microsoft Data Access Components (MDAC) 2.7. I mention MDAC because your developers might encounter problems with legacy ASP applications when running in side-by-side mode. (Side-by-side mode isn't a true mode; rather, it's a technique for implementing both old- and new-style code simultaneously. For example, ASP and ASP.NET are both Internet Server APIISAPIfilters, so they can run on the same IIS machine.) Although MDAC installations often strike fear in the hearts of IIS administrators, MDAC 2.7 installation is painless because it's simply an installation of ADO.NET, which has full XML support. Second, ASP.NET requires IIS 5.0 or later. So, ASP.NET won't run on NT 4.0 servers.
Installing the .NET Framework
Installing the .NET Framework on a server is no small chore, and the implications of putting that much code into the OS are spectacular. (For information about acquiring the .NET Framework, see the sidebar "Obtaining the .NET Framework.") Microsoft has a bootstrapper sample application that shows developers how to embed the .NET Framework into their .NET applications' setup code so that the .NET Framework installs automatically when their Web application installs. But can you imagine a software developer trying to convince you to let him or her install an application that includes tens, maybe hundreds, of megabytes of .NET Framework and Windows Component Update files necessary to install the .NET Framework?
The .NET Framework is included in the installation of the Windows Component Update. The Windows Component Update contains all the components that the .NET Framework installs and upgrades on an OS. Installation is a simple process requiring little or no decision-making, but it can take a long time on an inferior machine and will require a server reboot. Consider this requirement when you deploy the .NET Framework on your production servers.
Next Time
Having a good understanding of the .NET Framework before you even consider installing it into your production environment is imperative. You now know how to obtain the .NET Framework and what's required to install it. You should also have a good understanding of the .NET Framework's CLR and class library.
Next month, I'll continue this three-part series about integrating IIS and ASP.NET. In particular, I'll introduce you to ASP.NET's web.config filethe .NET equivalent of ASP's global.asa file.
End of Article
Sergey Lebedev June 15, 2004