Hello!
I am still working on a big web application in work. I will glad to tell you about the application, but this is for other conversation. I am glad to say that we are close to the end of the project and doing now last fine tuning on it.
The thing that I had to deal with for the last days is all the issue with publishing application errors in orderly fashion to the event viewer. The reason of doing it is to get the ability of tracking in runtime, bugs, errors or exceptions that can be appear while the application is in production. In this case we don't have the CLR debugger to find what was wrong (if something happend of course...), so we must publish the exception to the system's event viewer or just to a simple Log file (which less recommended then publishing to the system's event viewer).
Now, to the implementation (the imporatnt thing!!!)
In order to publish error to the event viewer, we need to use the Microsoft.ApplicationBlocks.ExceptionManagement assembly of Microsoft. This assembly expose us all the publishing tools that we will need to publish an errors (and more...).
In my web application, in global.asax file, in Application_Error method, I wanted to publish the exception to the event viewer. It is very important to do it there, because in every application error, like runtime errors, exceptions and actions that the application and systme doesn't know to deal with, this method is being called (by the application of course).
Now, before publishing the error to the event viewer, you need to distinguish between the different exceptions. Do it with your own information about every exception that is happening but, it is important to know that also in every response's redirect (Response.Redirect (" ... ", true) or server's transfer (Server.Transfer (" ... ", true) an ThreadAbortException is being raised.
Exception lastError = Server.GetLastError();
if (Server.GetLastError() is ThreadAbortException || lastError.InnerException is ThreadAbortException)
{
// Eat the exception - caused by Response.Redirect(..., true) or Server.Transfer(..., true).
Microsoft.ApplicationBlocks.ExceptionManagement.ExceptionManager.Publish(lastError.GetBaseException());
Server.ClearError();
}
else
{
Microsoft.ApplicationBlocks.ExceptionManagement.ExceptionManager.Publish(lastError.GetBaseException());
Server.ClearError();
Server.Transfer("~/Error.aspx", false);
}
By this example you can see the publish exceptions handling.
Now, do not forget to declare in the web.config file the appliation name and the exceptions pulishing handling:
<exceptionManagement mode="on">
<publisher assembly="Microsoft.ApplicationBlocks.ExceptionManagement" type="Microsoft.ApplicationBlocks.ExceptionManagement.DefaultPublisher" applicationname="APPLICATION_NAME"/>
</exceptionManagement>
One more thing... you need to register this assembly with the appliation name in the registry in purpose to let the application all the rights to publish the error in the event viewer, if you won't do it, the system won't let you write to the event viewer and you will get the exception: The event source ExceptionManagerInternalException does not exist and cannot be created with the current permissions. security exception and you will spend planty of time trying to solve it :) (like me...)
How to register this to the registry you ask?
Open notepad and write there this code:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Application\APPLICATION_NAME]
"EventMessageFile"="C:\\WINDOWS\\Microsoft.NET\\Framework\\v2.0.50727\\EventLogMessages.dll"
Save this file with .reg extension and double click on it, this will register this to the system's registry.
So, bye for now...