public class test {

  public static void main(String[] args) {

    long timer = java.lang.System.currentTimeMillis();
    for (int i = 0; i < 1; i++) {
      log.trace("Трассировка");
      log.debug("Отладка");
      log.info("Информация");
      log.warn("Предупреждение");
      log.error("Ошибка");
      log.fatal("Фатальная ошибка");
    }
    timer = java.lang.System.currentTimeMillis() - timer;
    java.lang.System.err.println(timer);
 }

  private static org.apache.log4j.Logger log = Logger.getLogger(test.class);

}

<?xml version="1.0" encoding="windows-1251"?>
<!DOCTYPE log4j:configuration PUBLIC "-//APACHE//DTD LOG4J 1.2//EN" "log4j.dtd">

<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" debug="true">

  <appender name="aConsole" class="org.apache.log4j.ConsoleAppender">
    <layout class="org.apache.log4j.EnhancedPatternLayout">
      <param name="ConversionPattern" value="|%d{yyyy-MM-dd HH:mm:ss.SSS Z}|%-5p|%t|%c|%m%n"/>
    </layout>
  </appender>

  <appender name="aNULL" class="org.apache.log4j.NullAppender">
    <layout class="org.apache.log4j.EnhancedPatternLayout">
      <param name="ConversionPattern" value="|%d{yyyy-MM-dd HH:mm:ss.SSS Z}|%-5p|%t|%c|%m%n"/>
    </layout>
  </appender>

  <appender name="ASYNC" class="org.apache.log4j.AsyncAppender">
    <appender-ref ref="aConsole"/>
  </appender>

  <logger name="root">
    level = "trace"
  </logger>

  <root>
    <priority value="info"/>
    <appender-ref ref="aNULL"/>
  </root>

</log4j:configuration>