Category Archives: Web Server

IIS Request Handling Process Model

IIS (Internet Information Server) is one of the most powerful web servers from Microsoft that is used to host your ASP.NET Web application. IIS has it’s own ASP.NET Process Engine  to handle the ASP.NET request. So, when a request comes from client to server, IIS takes that request and process it and send response back to clients.

Worker Process (w3wp.exe): Worker Process (w3wp.exe) runs the ASP.Net application in IIS. This process is responsible to manage all the request and response that are coming from client system. In short, Worker process is the heart of ASP.NET Web Application which runs on IIS.

Application Pool: Application pool is the container of worker process. Application pool is used to separate the sets of IIS worker processes that share the same configuration. This makes sure that the particular web application doesn’t impact other web application.

Note: One Application Pool can have one or many Worker Processes. An application pool with more than one worker process is called ‘Web Garden’.

HTTP.SYS Process: HTTP.SYS resides in Kernel Layer of IIS. HTTP.SYS is responsible for pass the request to particular Application pool. It contains the ID of each Application Pool. (Whenever we creates a new Application Pool, the ID of the Application Pool is being generated and it’s registered with the HTTP.SYS).

ISAPI extensions: ISAPI extensions are the IIS way to handle requests for different resources. Once ASP.NET is installed, it installs its own ISAPI extension (aspnet_isapi.dll) and adds the mapping into IIS.

IIS Request Handling Process Model

IIS Request Handling Process Model

 

Flow of ASP.NET Request:

 

1. Client Request hits the web server. Internally this request comes to Kernel Layer of IIS means at HTTP.SYS.
2. HTTP.SYS indentifies the name and ID of Application Pool for that ASP.NET Request.
3. Now Request comes to user level of IIS. WAS (Web Admin Service) puts the request from HTTP.SYS to Application Pool.
4. When Application pool receives the request, it simply passes the request to worker process (w3wp.exe).
5. The worker process “w3wp.exe” looks up the URL of the request in order to load the correct ISAPI extension (aspnet_isapi.dll).
6. ISAPI creates an HTTPRuntime Object to Process the request via HTTPModule and HTTPHanlder.HTTPRuntime is an entry point of the application.

 

Note: After these steps, after that the ASP.NET Page LifeCycle events starts.

How to install Internet Information Services (IIS)

IIS (Internet Information Server) is one of the most powerful web servers from Microsoft that is used to host your ASP.NET Web application. IIS has it’s own ASP.NET Process Engine  to handle the ASP.NET request. So, when a request comes from client to server, IIS takes that request and process it and send response back to clients.

Step 1 – Control Panel
Go to Control Panel -> Add Remove Programs 

Step 2 – Windows Configuration
Click Add/Remove Windows Components

Step 3 – Select IIS
The Windows Component Wizard will appear. You need to select the Internet Information Services (IIS) checkbox and then click Next.

How to install IIS

How to install IIS

Step 4 – Insert Your XP Professional CD
Now you will probably be asked to insert your Windows XP Professional CD.

Step 5 – Installing IIS

Once your Windows XP Professional CD (or network based installation) is available your Internet Information Services is being installed.

Now you have successfully installed IIS.

What is Web Server ?

A Web Server is a Computer or Combination of computers, which is connected through internet or intranet to serve the clients requests, coming from their web browser.

It is a large repository of web pages which transfer to the client in response to their request. The client send request to the server through protocol such as FTP, HTTP, SMTP etc. for their own specific use.

Every web server has a unique IP address and domain name which identifies that machine on the network. A server contains the server software installed on it, which manages the client request and response them.

what is web server.

what is web server.

The most widely used Web server Microsoft’s Internet Information Server ( IIS ) and Apache.

  • HTTP Server – It handles HTTP request coming from client’s browser and transfer the static pages to client in response to their request.
  • FTP Server – This type of server used for file transfer from one machine (Computer) to another using the internet or intranet. It uses File Transfer Protocols to transfer file from one computer to another.
  • Mail Server – A Mail Server store and retrieve mail messages from client mail box.
  • Application Server – It is installed database and web servers.

Every web page on the internet also has a unique address, called a Uniform Resource Locator, or URL. Something like “www.meeraacademy.com/page1.htm” is an example of a typical URL. When a user types that URL into a web browser, the machine the browser is running on sends a request to the IP address of the machine running the web server for that page, requesting that all the content found there be sent back. Once the web server receives that request, it sends the page content back to the IP address of the computer asking for it. The web browser then translates that content into all of the text, pictures, links, videos, etc. that so many web pages contain.