Since log4net does a great job at not clogging up the resources, I tend to be a little verbose on logging because when you have to change to debug mode, the more info you have, the better. Here’s what I typically log:
DEBUG Level
- Any parameters passed into the
method - Any row counts from result sets I retrieve
- Any datarows that may contain suspicious data when being passed down to the method
- Any “generated” file paths, connection strings, or other values that could get mungled up when being “pieced together” by the environment.
INFO Level
- The start and end of the method
- The start and end of any major loops
- The start of any major case/switch statements
ERROR Level
- Handled exceptions
- Invalid login attempts (if security is an issue)
- Bad data that I have intercepted forreporting
FATAL Level
- Unhandled exceptions.
Also having a lot of logging details prevents me from asking the user what they were doing when they got the error message. I can easily piece it together.