The Logging view allows dynamic integration with the Log4J logging framework. The top half of the page allows the logging level of any category to be dynamically set. This is useful when debugging, since logging output for specific classes [6] can be individually enabled or disable.
The right side is a small second form, allowing new categories to be created. This can be useful to make broad changes in logging levels. For instance, creating a category "org.apache.tapestry" would allow the logging level of all Tapestry classes to be set in a single place.
[6] By convention, logging categories match the complete class name of the corresponding class. All Tapestry logging categories conform to this convention.