13 Comments

  1. Hi Dan – unfortunately, a CPU profiler is almost never the right tool for diagnosing slow or hanging requests.

    Most of the time, slow requests happen due to either slow db/network IO, or an application deadlock. The profiler will not help you see this because these operations are not CPU intensive (they usually end by placing the thread in a WAIT state, e.g. WaitOnMultipleObjects).

    In the rare cases where you have a high CPU hang, CPU intensive code could be the culprit and a CPU profiler could help identify it.

    In all other cases, you are better off with a debugger to look at the stacks where the hanging requests are stuck.

    Best,
    Mike

  2. matt g.

    Nice! helped catch a request hang today.

    Do you plan to blog more about how to figure out application-wide deadlocks? That”s a very interesting topic for us.

  3. Hi Matt,

    I”ll definitely blog about this in a later post. There is a lot to cover. We are also adding a diagnostic for this in LeanSentry to automatically figure it out without forcing the user to become an expert in troubleshooting deadlocks.

    Best,
    Mike

  4. After reviewing your blog I still can’t decipher where to start troubleshooting the hung issue that is getting this returned in the appcmd dump….any clues?

    C:\Users\administrator.FCQA>%windir%\system32\inetsrv\appcmd list requests /elap
    sed:10000
    REQUEST “f60000008002939f” (url:GET /FCB/LoanForms/Html/test_start_page.aspx, ti
    me:18236 msec, client:10.10.22.122, stage:BeginRequest, module:IIS Web Core)

  5. TS

    Hi Mark,
    Thanks for this blog. I am facing issue that site is getting stuck all of a sudden. There is no fixed action or page. Site is developed with asp.net 4.0 and placed on IIS 7.0.

    I also want to know how I can enable the debugger in IIS so I can try to catch the issue why its hanging.

  6. George

    I’m trying to connect to the server using another server but when the request is made it says connected but HTTP request sent, awaiting response… 500 Internal Server Error. How can I correct this?

  7. Vincent

    I tried running appcmd list requests /elapsed:30000 after navigating to c://windows/system32/inetserv but powershell is telling me “The term ‘appcmd’ is not recognized as the name of a cmdlet, function, script file, or operable program.” even though I can see it right there. I also tried executing it in the command window and there I get no error but I also get nothing back. It just goes straight back to a blank command prompt. What am I missing here?

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