This might be a very simple and known to most of us, but I found it as a query in a discussion forum of one of my article “Debug your ASP.NET Application while Hosted on IIS” which was published at Code Project . Question was regarding list of worker processes in “Process Attach window” of Visual studio. Though all the sites are running properly on IIS, still he was not able to view any processes in “Attach Process Window” while trying to attach a process from Visual Studio.
In one of my previous blog post, Identifying Worker Process (w3wp.exe) – IIS 6.0 and IIS 7.0 for Debugging ASP.NET Application – I have explained about how we can identify the list of currently running worker process using command prompt while we need to attach process from visual studio . But do you know for IIS 7.0 and IIS 7.5 we can get the worker process (w3wp.exe) details like Application Pool name, Process ID, CPU Usages from IIS Manager itself. Even you can get details of each worker process for a “Web Garden” scenarios. So when you need to attach some process for debugging from Visual studio, Instead of going to command prompt, you can easily identify the worker process Id from IIS itself.
In this blog post I have going to list out all of my IIS articles that I have published over last few years. Why I am going to do such post ? Because, I have been asked many question on IIS and different debugging options related with IIS and ASP.NET Applications by many readers. Many times I have had given reference of my different articles. This post will be the single reference for all of those articles. In this blog post I have given link and small overview of all of my IIS articles, so that I can refer a single articles to who ever wants to learn about IIS.
This article describes details of IIS configuration, Virtual Directory creation, Application Pool Creation, Application Pool settings, IIS Request processing for ASP.NET .
If you are debugging a ASP.NET web application which is hosted on IIS, you need to attach the particular worker process in Visual Studio to start debugging. To Attach a process we can go to Tools > Attach Process or use shortcut key Ctrl +P. The process window will show the worker process (w3wp.exe) which is currently running on IIS. You need to select the process and click on attach button to start the debugging.
Problem starts when you have multiple worker process running on IIS. If you have multiple sites hosted on IIS and each site having their own application pool then you will see the list of all worker process in the Process Attach window.
Here you need to identify the particular worker process which is associated with your application pool.
Note: Whenever we create a new Application Pool, the ID of the Application Pool is being generated and it’s registered with the HTTP.SYS (Kernel Level of IIS) . So whenever HTTP.SYS Received the request from any web application, it checks for the Application Pool and based on the application pool it send the request