The root logger for the production server configuration's conf/log4j.xml file has no set priority. This means that DEBUG is used by default which in turn means that you have to enumerate categories to turn logging off rather than turn it on. Production system's likely don't need DEBUG level logging, so the root logger's severity/priority should be INFO, otherwise, we could run into problems with 3rd-party libraries (like Hibernate for example) that generate lots of DEBUG-level logging in production if they are not specifically changed with a category statement.