Logs are probably one of the most important parts of an application, whatever technology it uses. Why is that? Because without logs, you have no idea what your application is doing or why your application is behaving in a particular way.
Of course, we saw in Chapter 3, Monitor Your Application, how to instrument the application to get some monitoring information about the JVM and application, but it was very technical and mainly performance or tracking oriented. This is important but rarely enough and generally not helpful enough for operation and support teams who generally prefer a higher level view of application tracing. This is where logging enters into the game. However, it is important that you correctly use it and configure it, so that you do not impact your application performance.
You may think that Java EE and logging are...