This document discusses ASP.NET request processing internals. It begins by explaining the role of the web server and walking through the ASP.NET request pipeline. It then dives deeper into how IIS handles requests by using application pools, worker processes, and HTTP.SYS. The document demonstrates how requests flow from the client, through IIS and HTTP.SYS, to the worker process which executes the ASP.NET page lifecycle. It also covers HTTP modules and handlers and how they fit into request processing.

1. ASP.NET Request Processing Internals Abhijit Jana Consultant | Microsoft http://abhijitjana.net

2. Agenda Role of Web Server ASP.NET Request Processing Internals Internal of Web Server Request Processing Request Pipeline Page Life Cycle

4. ASP.NET Development Server

5. WebDev.WebServer20.exe ( CLR 2.0 )

6. WebDev.WebServer40.exe (CLR 4.0 )

8. Moving to IIS Process Request (w3wp.exe) Request Response

9. Key Concept Application Pool Worker Process Web Farm Web Garden IIS Application Pool Application Pool Application Pool Worker Process Worker Process Worker Process w3wp Web Application 1 Web Application 2 Web Application 3 Web Application 4

10. Application Pool and HTTP.SYS IIS Application Pool Application Pool Application Pool W3wp.exe W3wp.exe W3wp.exe HTTP.SYS ApplicationHost.Config

11. Demo

12. Protocol Listener [ HTTP.SYS ] Protocol Listener is the part of Kernel Level of IIS Protocol listeners receive protocol-specific requests send them to IIS for processing return responses to requestors It the Kernel mode Protocol stack which listens to the HTTP and HTTPSRequest Kernel-mode caching Kernel Mode Queuing

13. WWW service and WAS Part of User Level of IIS World Wide Web Publishing Service (WWW service) and Windows Process Activation Service (WAS) run as Local System in the same Svchost.exe process Performance Monitoring Processing Monitoring Configuration Management Svchost.exe Windows Process Activation Service (WAS) World Wide Web Publishing Service (WWW service) HTTP.SYS

14. Overall View Of IIS Application Pool ApplicationHost.Config Svchost.exe World Wide Web Publishing Service (WWW service) Windows Process Activation Service (WAS) HTTP.SYS

15. Looking bit Inside of Request Processing HTTP Module HTTP Module IIS HTTP Module Application Pool Application Pool Svchost.exe Application Pool W3wp.exe W3wp.exe W3wp.exe WWW service WAS HTTP Module HTTP Module HTTP.SYS HTTP Handler HTTP Handler

17. HTTP.sys Interacts with WWW Publishing Services and sync with the related configuration stored in applicationHost.config.

18. The WWW Service receives configuration like application pool, virtual directory, site details from applcationHost.config

19. WWW Publishing Services gets the request from Http.Sys and passed to WAS

20. WAS starts a worker process for the application pool associated with the request was made.

21. Workerprocess execute ASP.NET Internals operations

22. The worker process processes returns a response to HTTP.sys.

24. Demo

25. Inside Worker Process (w3wp.exe) cond.. W3wp.exe Web Server Core Modules BeginRequest BasicAuthenticationModule Authentication HttpCacheModule Authorization StaticCompressionModule Cache Resolution DynamicStaticCompressionModule Handler URL Authorization Release State Tracing Update Log HTTP Error End Request Processing HTTP Logging

27. Plug-in / out modules you want on the server or Application Specific.

28. customize a server to a specific role in your environment.

29. custom modules to replace existing modules or to introduce new features based on application on server specific

30. Content Module ( IsapiFilter ,IsapiFilterModule )

31. Security Module (BasicAuthenticationModule )

32. Caching Module ( HttpCacheModule)

33. Compression Module ( StaticCompressionModule )HTTP Module HTTP Module HTTP Module HTTP Module HTTP Module HTTP Handler HTTP Handler

34. ASP.NET Routing W3wp.exe Web Server Core BeginRequest Authentication Routing Module Authorization Cache Resolution Handler IHandler Release State Update Log End Request Processing

35. Once done with HTTP Pipeline Page_PreInit Page_Init ASP.NET Page Life Cycle Load View State Load Post Back Data Page_Load Page Post back event Pre Render Save View State Render Unload

36. Summary

38. IIS URL Rewriting and ASP.NET Routing

39. IIS 7.0 Request Filtering and URL Rewriting

41. Thank You ! Abhijit Jana Blog : http://abhijitjana.net http://dailydotnettips.com Twitter : @AbhijitJana