Could not start IIS - CannotStartSessionException

Hi all,
I am trying to use ANTS Performance Profiler to analyse performance for a website running on II6(32 bit mode) on WIndows 2003 x64.
The site contains .NET 1.1 compiled binary files but runs under ASP.NET 2.0(32 bit version).
I managed to get the test going under IIS default port but if I try to run it on a unused port (8013 is the one proposed in Application settings) I have this exception :
Could not start IIS.
at bJ.Launch()
at RedGate.Profiler.Session.ProfilerSession.j()

Caused by:

Could not start IIS.
at bQ.PerformLaunch()
at bJ.Launch()

Caused by:

Object reference not set to an instance of an object.
stack trace:
at RedGate.Profiler.Engine.Startup.IIS.IIS6Utilities.GetW3wpArgs(Uri url, Boolean profileOnNewPort, Int32 newPort)
at bp.StartProfilingIIS(String currentUserName, String subprocessVariableValue)
at RedGate.Profiler.Engine.Startup.IIS.IISStarter`1.StartProfilingIIS(String currentUserName, String subprocessVariableValue)
at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Int32 methodPtr, Boolean fExecuteInContext, Object[]& outArgs)
at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg, Int32 methodPtr, Boolean fExecuteInContext)
rethrown at [0]:
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at RedGate.Profiler.Engine.Startup.IIISActuator`1.StartProfilingIIS(String currentUserName, String subprocessVariableValue)
at bQ.PerformLaunch()


  • Sorry you are having problems, can you use ensure you are using "classic" mode for your app pool?

    You could also extend the timeout of app pool startup (I use 99 seconds, just to be sure!)

    Please try that and let me know if you have any further problems.
  • Hi,
    I am using II6 so there is no classic mode. The reported error only comes up if I try to start a profiling session using an unused port( in order to prevent the worker process that hosts the actual site to restart as per ANTS Performance Profiler) documentation.
  • Sorry for the long delay in response- I kept on trying to reproduce this and it wasn't easy. I finally did this and the upshot is - its now bug number PP-703. I am now lobbying for the fix to be in the next major relase for the product.
  • Are there any workarounds in the short term? Restarting IIS to profile on the original port works, but it's a bit unfriendly on a shared server.

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