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Use exception handlers to define critical exceptions

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Exception handlers are application functions that "catch" exceptions that the applications throw to report errors and perform some error handling. By default, .NET Application Performance Monitoring defines critical exceptions as exceptions handled by specific exception handlers provided by the .NET framework. These handlers catch top-level ASP.NET exceptions, and web service exceptions that the monitored application failed to catch and handle internally. By adding exception handlers, you're adding to what application monitoring's definition of what a critical exception is. In effect, any exceptions handled by these functions will be considered critical exceptions. The advantage to doing this is that you maintain the benefit of streamlined reporting of critical exceptions only, but you've the additional benefit of reporting functions that are of interest to you. It's common to add any customer error handlers defined for web applications to the list of critical exception handlers so that you can be alerted when a user is sent to your error handler page in the web application.

Warning

Exception handlers are set on the process level. If you enable an exception handler for an application that is running in the process and then disable it for a different application running in that process, there will be a configuration conflict and application monitoring will be disabled. To resolve this, you must make the exception handling the same for all applications in the same process.

Default exception handlers

The default list of exception handlers includes:

  • Web.HttpApplication.RecordError
  • Web.UI.Page.HandleError
  • Web.Services.Protocols.WebServiceHandler.WriteException
  • AppDomain.OnUnhandledExceptionEvent
  • Windows.Forms.Application.ThreadContext.OnThreadException
  • AppDomain.OnUnhandledExceptionEvent
  • Runtime.Remoting.Messaging.ReturnMessage..ctor
  • Windows.Forms.DataGridView.OnDataError

Add an exception handler

To add an exception handler, follow these steps:

  1. To open the .NET Application Performance Monitoring template, in the Operations Manager console, in the navigation pane, select the Authoring button, select Management Pack Templates, and select .NET Application Performance Monitoring.

  2. Right-click the application group you want to modify, and then select Properties.

  3. On the Server-Side Defaults tab, select Advanced Settings.

  4. On the Advanced settings page, select Critical Exceptions to open the Exception handlers list page. This is where you can add exception handlers.

  5. To add an exception handler, select Add and enter the method you want to add to the exception handlers list. If you want this exception handler to affect monitoring, ensure the Enable monitoring checkbox is selected. Select OK.

    Important

    Adding handlers that are defined in the .NET Framework as part of mscorlib as Critical Exceptions won't produce any effect.

    Note

    The method name is case sensitive and should be specified in the following format: Namespace.ClassName.MethodName

Edit an exception handler

To edit an exception handler, follow these steps:

  1. Open the .NET Application Performance Monitoring template. In the Operations Manager console, in the navigation pane, select the Authoring button, select Management Pack Templates, and select .NET Application Performance Monitoring.

  2. Right-click the application group you want to modify and select Properties.

  3. On the Server-Side Defaults tab, select Advanced Settings.

  4. On the Advanced settings page, select Critical Exceptions. This opens the Exception handlers list page where you can edit exception handlers.

  5. To edit an exception handler, select Edit, select the exception handler you want to change, and then modify it. Select OK.

    Note

    The method name is case sensitive. Additionally, the method name should be specified in the following format: Namespace.ClassName.MethodName

Remove an exception handler

To remove an exception handler, follow these steps:

  1. Open the .NET Application Performance Monitoring template. In the Operations Manager console, in the navigation pane, select the Authoring button, select Management Pack Templates, and select .NET Application Performance Monitoring.
  2. Right-click the application group you want to modify and select Properties.
  3. On the Server-Side Defaults tab, select Advanced Settings.
  4. On the Advanced settings page, select Critical Exceptions. This opens the Exception handlers list page where you can remove exception handlers.
  5. To remove an exception handler, select the exception handler you want to remove, select Remove, and select OK.