Access Denied when using the ULS Log System

Question

I was following this tutorial:

http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.administration.spdiagnosticsservicebase.aspx

But I got an access denied:

protected override void Render(System.Web.UI.HtmlTextWriter writer)
{
    using (new SPMonitoredScope("RenderMethod"))
    {
         writer.Write(DisplayMessage);

         DiagnosticsService myULS = DiagnosticsService.Local; // ACCESS DENIED
         if (myULS != null)
         {
             SPDiagnosticsCategory cat = myULS[CategoryId.Provisioning];
             string format = "Tracing test of {0} service";
             myULS.WriteTrace(1, cat, TraceSeverity.Verbose, format, myULS.TypeName);
             myULS.WriteEvent(1, cat, EventSeverity.Information, format, myULS.TypeName);
         }
    }
}

I tried the following on a console application and the diagSvc is always null

SPDiagnosticsService diagSvc = SPDiagnosticsService.Local;
diagSvc.WriteTrace( 0, // custom trace id
    new SPDiagnosticsCategory("My category", 
        TraceSeverity.Monitorable, 
        EventSeverity.Error), // create a category
    TraceSeverity.Monitorable, // set the logging level of this record
    "Writing to the ULS log:  {0}", // custom message
    new object[] { "SharePoint rocks!"} // parameters to message
);

Answer 1

The "registration" of a subclass of SPDiagnosticBase requires Farm admin privileges.

The registration occurs on first access.

You'll need to call "DiagnosticsService.Local" in a context with Farm admin priveleges.

When you ran your console app you probably ran it as a farm admin user and the registration succeeded.

If you try to install your code on another system it will most likely fail again.

I would recommend to call DiagnosticService.Local in the FeatureInstalled method of a FeatureEventReceiver as they are called with Farm admin priveleges.

Answer 2

If you're running on SP2010, you probably need SPSecurity.RunWithElevatedPrivileges. I realize this is a very old question, but fellow Googlers might find this helpful :)

Answer 3

I found the answer, and posted on my blog here:

http://www.sharepoint2010blogger.com/2010/10/10/spfarm-gets-null-or-spdiagnosticsservice-local-gets-null/

Answer 4

Open Project Properties -> Build Target -> Platform Target -> Change from x86 to x64. Save the project and execute again.