Harish Ranganathan
Application Platform Evangelist
Microsoft India

AGENDA
• HTTP Runtime • HTTP Context
• IIS & ASP.NET Relation • Global.asax
• HTTP Modules • Page Framework
• HTTP Handlers • Best Practices

HTTP Runtime
• A low-level HTTP processing infrastructure
• Logical replacement for ISAPI filters/extensions
• Ability to add, replace, or remove core pieces of
the product
• Benefits: Built-in thread pool, asynchronous
support, access to ASP.NET intrinsic objects

HTTP Runtime

Http Runtime

IIS-ASP.NET Relation
w3wp.exe (IIS 6.0)
http.sys (Kernel Mode)

IIS-ASP.NET Relation
Document types are
mapped to ISAPI
extensions in the IIS
Manager

IIS – ASP.NET Relation

HTTP Pipeline
HTTP
IIS aspnet_isapi HttpModules HttpHandler
Request

HTTP Modules
• Called before and after the handler executes
• Ability to intercept, participate or modify each
individual request into an application
Ex: Changing URL in request/response to hide
server names behind firewall.
• The HTTP Application provides several events
that modules can synchronize with

HTTP Modules
• Global Application Events:
– Start
– End
• Per request events (in order):
– BeginRequest – PreRequestHandlerExecute
– AuthenticateRequest – PostRequestHandlerExecute
– AuthorizeRequest – ReleaseRequestState
– ResolveRequestCache – UpdateRequestCache
– AcquireRequestState – EndRequest
• Per request events (non-deterministic):
– PreSendRequestHeaders
– PreSendRequestContent
– Error

HTTP Modules
Built-In HTTP Modules:
• Authentication Modules
• Authorization Modules
• OutputCache Module
• SessionState Module
• Configuring HTTP Modules
– Use httpModules section handler
• View the Machine.Config

HTTP Handlers
• Handlers:
– Are the endpoint in the request process
– Only one handler is invoked per request
• Examples
– ASP.NET Page Handler:
• Implements the ASP.NET Page Framework
• Processes all requests for .aspx pages
– ASP.NET Service Handler:
• Implements Web Services
• Processes all requests for .asmx pages
• Configuring HTTP Handlers

HTTP Handlers & Modules

HTTP Context
• Encapsulates all information about an individual
HTTP request
• ASP.NET intrinsic objects are exposed as properties
of the HttpContext
• Modules and Handlers get a reference to an
HttpContext object representing the current
request
• Flows through the lifetime of a request

HTTP Context
• ASP.NET supports all ASP classic members
Property Managed Class
– Request HttpRequest
– Response HttpResponse
– Server HttpServerUtility
– Session HttpSessionState
– Application HttpApplicationState
• ASP.NET adds several new and useful members
– Request.Files
– Response.Cache
– Error/User/Trace

Global.asax
• Extends on the familiar functionality of the
Global.asa
• Global.asax must be located in the root of a Web
application
• Enables easy handling of Application level events
without a custom HttpModule

Global.asax
Updates:
• Are automatically detected
• Causes the Global.asax to be recompiled
• Restarts the HTTP Application
• ASP.NET completes all current requests before
shutting down old application
• Fires Application_End event
• Shuts down App Domain

HTTP Context & Global.asax

Page Framework
• Overview
• Page Object
• Page Lifecycle
• Page Events
• Control Tree
• Page Directives

Page Framework
Page Object:
• Inherits from Control, implements IHttpHandler
• All .aspx pages inherit from Page
• Exposes the ASP.NET intrinsics
• Wires up events (Page_Load, Page_Init…)

Page Framework
Init
Page Lifecycle: LoadViewState
Constructor PostBack Data Processing
Load
ProcessRequest
(hidden from user)
PostBack Change Notification
PostBack Event Handling
PreRender
SaveViewState
Render
Dispose

Page Framework

Best Practices
• Return Multiple Resultsets
• Paged Data Access
• Connection Pooling
• ASP.NET Cache API
• Per Request caching
• Background Processing

Best Practices
• Page Output Caching and Proxy Servers
• Session State & Viewstate
• Debug vs. Release
• Exception Handling

Related Content
Breakout Sessions (session codes and titles)
Interactive Theater Sessions (session codes and titles)
Hands-on Labs (session codes and titles)
Hands-on Labs (session codes and titles)

Track Resources
Resource 1
Resource 2
Resource 3
Resource 4

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not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS,
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