Introduction to IIS Architecture:

IIS 7.0

• The Windows Process Activation Service (WAS), which enables sites to use protocols other than HTTP and HTTPS.
• A Web server engine that can be customized by adding or removing modules.
• Integrated request-processing pipelines from IIS and ASP.NET.

This article describes the components, modules, and request-processing architecture in the following sections:

• Components in IIS
• Protocol Listeners
• Hypertext Transfer Protocol Stack (HTTP.sys)
• World Wide Web Publishing Service (WWW service)
• Windows Process Activation Service (WAS)
• Modules in IIS
• Native Modules
• Managed Modules
• Request Processing in IIS
• Application Pools in IIS
• HTTP Request Processing in IIS

Compoents in IIS

IIS contains several components that perform important functions for the application and Web server roles in Windows Server® 2008 (IIS 7.0) and Windows Server 2008 R2 (IIS 7.5).

Each component has responsibilities, such as listening for requests made to the server, managing processes, and reading configuration files.

• Protocol listeners - HTTP.sys
• Services - World Wide Web Publishing Service (WWW service) and Windows Process Activation Service (WAS).