What logging is good logging for your app?

Question

So we've discussed logging in passing at my place of work and I was wondering if some of you guys here could give me some ideas of your approaches?

Typically our scenario is, no logging really at all, and mostly .NET apps, winforms/WPF clients talking through web services or direct to a db.

So, the real question is, where or what would you log? At the moment we have users reporting error messages - so I would assume log startups/shutdowns, exceptions...

Do you take it to calls to the web services or db? Page loads?

How do you get a good idea of what the user was trying to do at the time?

Is it better to go all the way and log everything across multiple attempts/days, or log only what you need to (given hdd is cheap).

I guess that's a few questions, but I wanted to get more of an idea of what the actual practice is out there in larger shops!

Answer 1

This post on highscalability.com provides a good perspective on logging in a large scale distributed system. (And coincidentally it starts out by mentioning a post on the JoelOnSoftware).