A sample MVC application in Visual Studio 2010 configured to use local IIS web server

1. Enable profiling for w3wp.exe.

a) Find the application pool for the app.

Check IIS Manager, Sites – Default Web Site – MvcApplication1, Basic Settings. In my case the pool is DefaultAppPool:

Application pool in IIS manager

b) Enable user profile loading for the pool.

IIS Manager, Application Pools, DefaultAppPool, Advanced Settings, Process Model – Load User Profile, set to True:

Application pools in IIS manager

Advanced application pool settings

c) Find SID of the pool account.

From the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList key find ProfileImagePath with DefaultAppPool. In my case the SID is S-1-5-82-3006700770-424185619-1745488364-794895919-4004696415:

DefaultAppPool SID in registry

d) Set environment variables to invoke Runtime Flow profiler.

Using the found SID, add two string values to HKEY_USERS\S-1-5-82-3006700770-424185619-1745488364-794895919-4004696415\Environment:

Cor_Enable_Profiling=1
COR_PROFILER={C967CF3F-79BF-49a5-A10F-D5B269DB9E54}

Environment settings for DefaultAppPool

2. Close all running w3wp.exe processes.

In IIS Manager restart server.

3. Run monitoring.

In Runtime Flow – Customized Run, uncheck Stop monitoring when the command completes. Set Command to “C:\Program Files\Internet Explorer\iexplore.exe”. Set Command arguments to “http://localhost/MvcApplication1″. Optionally set Options – Monitoring Filter to “Module == MvcApplication1.dll”:

Customized run of Internet Explorer

Runtime Flow monitoring results

Download links: Visual Studio edition, Portable edition.

Download links: Visual Studio edition, Portable edition.

    class Program
    {
        static void Main(string[] args)
        {
            f(1);
        }

        static void f(int i)
        {
            if (i < 500)
                f(i + 1);
        }
    }

In Runtime Flow portable you can open maximum 58 recursive calls:

Maximum supported stack depth in Runtime Flow .NET 3.5

Layout recursion limit reached WPF error

The same problem exists when you view monitoring results in Visual Studio 2008/2005. In .NET 4.0 the layout recursion limit is increased from 255 to 4096. So in Visual Studio 2010 you can view much deeper stacks (though not 1024 deep due to other limitations).

I’ve created an additional Runtime Flow portable binary built for .NET 4.0 to enable more deep stack investigations:

Runtime Flow portable binaries for .NET 3.5 and .NET 4.0

If you have .NET 4.0 installed on the machine, it is now recommended to use RuntimeFlowPortable.NET40.exe instead of RuntimeFlowPortable.NET35.exe. It supports stacks up to 285 function calls:

Maximum supported stack depth in Runtime Flow .NET 4.0

Download link: Runtime Flow portable edition v1.3.1.

The Pause button on the Runtime Flow toolbar

Pause stops all updates to the Runtime Flow and Runtime Summary windows and eliminates most of monitoring overhead (speeding up the monitored application and limiting memory consumption). In this mode you can browse collected events and execute tasks in your application not required monitoring.

When you are ready to run a next use case, press the Resume button:

The Resume button on the Runtime Flow toolbar

Resume clears the Runtime Flow and Runtime Summary windows and resumes normal monitoring events processing.

The most common case to not collect monitoring data is to skip application startup. For convenience, I’ve added the Monitor application startup option:

Monitor application startup option

With Monitor application startup unchecked, no flow data is collected until you click the Resume button. This is useful when monitoring complex apps with very big initialization routines that you are not interested in.

Download links for Runtime Flow v1.3.0: Visual Studio edition, Portable edition.

Download links: Visual Studio edition, Portable edition.