title: How to determine what log level to use?
body: <p>The log levels WARN, ERROR and FATAL are pretty clear. But when is something DEBUG, and when INFO? </p>
  
  <p>I've seen some projects that are annoyingly verbose on the INFO level, but I've also seen code that favors the DEBUG level too much. In both cases, useful information is hidden in the noise.</p>
  
  <p>What are the criteria for determining log levels?  </p>