With log4j.xml per-deployment logging, the appenders are added within the org.apache.log4j.Logger.getLogger() call. Currently System.out.println("foo") initializes no-handler "stdout" logger which is essencially no-op.

To workaround, initializing the following 2 loggers before using System.out/err.

org.apache.log4j.Logger.getLogger("stdout");
org.apache.log4j.Logger.getLogger("stderr");