How do you log errors (Exceptions) in your ASP.NET

Question

I'm looking for the best way to log errors in an ASP.NET application. I want to be able to receive emails when errors occurs in my application, with detailed information about the Exception and the current Request.

In my company we used to have our own ErrorMailer, catching everything in the Global.asax Application_Error. It was "Ok" but not very flexible nor configurable.

We switched recently to NLog. It's much more configurable, we can define different targets for the errors, filter them, buffer them (not tried yet). It's a very good improvement.

But I discovered lately that there's a whole Namespace in the .Net framework for this purpose : System.Web.Management and it can be configured in the healthMonitoring section of web.config.

Have you ever worked with .Net health monitoring? What is your solution for error logging?

Answer 1

My team uses log4net from Apache. It's pretty lightweight and easy to setup. Best of all, it's completely configurable from the web.config file, so once you've got the hooks in your code setup, you can completely change the way logging is done just by changing the web.config file.

log4net supports logging to a wide variety of locations - database, email, text file, Windows event log, etc. My team has it configured to send detailed error information to a database, and also send an email to the entire team with enough information for us to determine in which part of the code the error originated. Then we know who is responsible for that piece of code, and they can go to the database to get more detailed information.

Answer 2

We use a custom homegrown logging util we wrote. It requires you to implement logging on your own everywhere you need it. But, it also allows you to capture a lot more than just the exception.

For example our code would look like this:

Try
  Dim p as New Person()
  p.Name = "Joe"
  p.Age = 30
Catch ex as Exception
  Log.LogException(ex,"Err creating person and assigning name/age")
  Throw ex
End Try

This way our logger will write all the info we need to a SQL database. We have email alerts set up at the DB level to look for certain errors or frequently occurring errors. It helps us identify exactly where the errors are coming from.

This might not be exactly what you're looking for. Another approach similar to using Global.asax is to us a code injection technique like AOP with PostSharp. This allows you to inject custom code at the beginning and end of every method or on every exception. It's an interesting approach but I believe it may have a heavy performance overhead.