Internet Information Services (IIS) Interview Questions And Answers

By default Each Application Pool runs with a Single Worker Process (W3Wp.exe). We can assign multiple Worker Process With a Single Application Pool. An Application Poll with multiple Worker process called Web Gardens. Each Worker Process Should have there own Thread and Own Memory space.

For creating web graden we need to go to Application Pool, then Right Click on Application Pool > Properties > Goto Performance Tab

In Web Garden Section, increase the number of worker process. By default it is 1.

Right click on Application Pool ->All Task ->Save Configuration to a File.
It will save the configuration file in xml format.

Application Pool stated that Multiple web applications or Group of web applications.
Application pool contain one or more Web URLs used by Worker processes.For one website or many website we can assign Application Pool, to avoid the effect of other website need to create seperate Application Pool.

Though we can create new application pool IIS with different settings, but IIS having its own default application pool named: DefaultAppPool

Open IIS Configuration Manager
First of all Right Click on Default web sites > New > Virtual Directory .
Browse the Physical Path. Set the properites. Click on OK

Yes. We can.
While creating Application Application Pool From IIS, there should have two option available first one is for Default Setting and Another is for Existing Setting as template.
We can select the second one and from the drop down listed below we can select any on the Application Pool as Template,.

1. Anonymous ( Default Authentication in IIS runs under IUSER_servername )
2. Integrated Windows Authentication
3. Basic Authentication
4. Digest Authentication
5. Passport Authentication

Use the following command “IISRESET”.

<Drive>:inetpubwwwroot

1. None
2. Scripts Only
3. Scripts and Executable

IIS having mainly two layer Kernel Mode and User Mode

Below are the subsection of both of them.
1. Kernel Mode
☛ HTTP.SYS

2. User Mode
☛ Web Admin Service
☛ Virtual Directory
☛ Application Pool

For IIS 6.0 – NetworkServices,LocalService,LocalSystem

For IIS 7.0 – NetworkServices,LocalService,LocalSystem and Application Pool Identity.

ISAPI filters are DLL files used to modify the enhance functionality allocated by IIS.By default ISAPI filters run in IIS server.

change request URL or headers
perform custom authentication
Handle encryption and compression

Configure multiple work process on one application pool in a web server is called as Web Garden.Application Pool can configure for multiple websites hosted in IIS.

App Pool and App Domain both are for isolations on different approches.App Pool use process to isolate without .net but for App Domain isolation methods by .net.

In Simple terms
For Multiple websites in IIS need different Application Pool.
In Single domain purpose we use Application Domain.

IIS having three different Identity.
1. Local System
2. Local Services
3. NetworkServices

This is one of the most question in IIS. And along with that interviewer can as what is the different between Web farm and Web Garden ?

When we hosted our web Application on multiple web server under a load balancer call the Web Farm. This is generally used for heavy load web application where there are many user request at a time. So When Web Application is hosted on Different IIS Server over a load balancer, Load balancer is responsible for distribute the load on different server.

HTTP.SYS is the kernel level components of IIS. All client request comes from client hit the HTTP.Sys of Kernel level. HTTP.SYS then makes a queue for each and every request for each and individual application pool based on the request.
Whenever we create any application pool IIS automatically registers the pool with HTTP.SYS to identify the particular during request processing.

Network Services

For IIS 6.0 > w3wp.exe
For IIS 7.0 > w3wp.exe
in IIS 5.1 worker process is aspnet_wp.exe.

First identify the Application pool name and process ID using cscript iisapi.vbs script.Later attach process from Visual Studio IDE.

Default Identity of IIS 6.0 is NetworkServices .
Which is having very minimum rights on your system. The user can only have the read access of the site.

We can set the Idle time out for an worker process from Application Pool Properties.

In Performance Tab of Application pool, we can set the Idle Time out of the worker process. This means worker process will shut down after that given time period if it stay idle. And will again wake up again if a new request comes.

Visual studio having It own ASP.NET Engine which is capable enough to run Asp.net web application from visual studio. So we just click on Run button to start the application.
Now this is the scenarios of local environment. But If we want to host it on server from where all user can access the sites then IIS comes into the picture.

IIS provides a redesigned WWW architecture that can help you achieve better performance, reliability, scalability, and security for our Web sites. IIS can support following Protocol HTTP/HTTPS, FTP, FTPS, SMTP Etc. We need to host the site on IIS, when request comes from client it first hits the IIS Server, then the server passed it to ASP.NET worker process to execute. Then the response also passes to client via IIS itself.