Is there any documentation about the details of a given logger,
e.g. org.xwiki.notifications.filters.internal.UserAddedEventListener
- How is the logger configured?
- What is it logging at each Log-Level?
You might want to look at https://www.xwiki.org/xwiki/bin/view/Documentation/AdminGuide/Logging#HConfiguringLogging. By default, all loggers are configured in logback.xml, and you can see in the Log administration what is the level of each logger.
I think in most cases you will have to look at the class to know this (each logger is a class or a package which contains classes). And in this specific case, the answer is that it only has one error log, so not much to configure.