The Logging in Tomcat documentation states in the Log4J section on step 2 states: Download Log4J (v1.2 or later). This is incorrect. The current version of log4j (2.1) does not work with Tomcat 8. I have verified this. I configured per the instructions and log4j did not work. When I replaced the 2.1 jar with the current 1.2.x jar, logging worked as expected. The documentation should reflect that version 1.2.x is required, or Tomcat should be updated to work with the 2.1 jar and the documentation updated to reflect that requirement.
Fix in trunk, 8.0.x (for 8.0.19 onwards), 7.0.x (for 7.0.60 onwards) and 6.0.x (for 6.0.44 onwards).