Professional Microsoft IIS 8

IIS 7.0 and Later Architecture

Although the architecture in IIS 7.0 and later versions is quite different from that of IIS 6.0 and prior versions and the code base has been entirely rewritten, many of the concepts and most of the architecture of the IIS family live on. ISAPI still exists, even though pipeline modules can be written to replace most ISAPI applications. The worker process and application pools are still in place, and inetinfo.exe and Http.sys still perform similar functions. In IIS 7.0 and above, the web server has become the application server, an integral part of the operating system included in all versions of Windows Server 2008 and later. IIS 8.0, which contains the code from IIS 7.0, includes all the functions and processes from IIS 7.0.

Whereas IIS 6.0 was the supporting platform for many applications, from ASP and ASP.NET to SharePoint, later versions of IIS have become part of the application itself. In many ways, IIS is now the application framework, supporting the application code and function. The architecture of IIS has been designed around this concept, allowing developers great freedom to alter, tune, and improve not only their applications, but also now the web server itself. The modularity and extensibility of IIS now goes far beyond the capability of ISAPI extensions, which in IIS 6.0 were tacked on as handlers for specific file types. Developers can now modify the server functionality to meet the needs of the application.

Pipeline Modes

A major ...