10 примеров Appender-ов для LOG4J

  <!-- ============================== -->
  <!-- A size based rolling appender -->
  <!-- ============================== -->
  <appender name="CUSTOMER_FILE_LOG"
    class="org.apache.log4j.RollingFileAppender">
    <param name="File" value="${oracle.j2ee.home}/log/sdp/system/system.log" />
    <param name="Append" value="true" />
    <param name="Encoding" value="UTF-8" />
    <param name="MaxFileSize" value="100000KB" />
    <param name="MaxBackupIndex" value="10" />

    <layout class="org.apache.log4j.PatternLayout">
      <param name="ConversionPattern"
        value="%d{yyyy-MM-dd HH:mm:ss,SSSZ} %-5r %-5p [%c{1}] (%t:%x) %m%n" />
    </layout>
  </appender>

  <!-- ============================== -->
  <!-- A size based rolling appender -->
  <!-- ============================== -->
  <appender name="TRAFFIC_FILE_LOG"
    class="org.apache.log4j.RollingFileAppender">
    <param name="File" value="${oracle.j2ee.home}/log/sdp/traffic/traffic.log" />
    <param name="Append" value="true" />
    <param name="Encoding" value="UTF-8" />
    <param name="MaxFileSize" value="100000KB" />
    <param name="MaxBackupIndex" value="10" />

    <layout class="org.apache.log4j.PatternLayout">
      <param name="ConversionPattern"
        value="%d{ISO8601} %-5p [%c{1}] (%t:%x) %m%n" />
    </layout>
  </appender>

  <!-- ============================== -->
  <!-- A size based rolling appender -->
  <!-- ============================== -->
  <appender name="BADMSG_FILE_LOG"
    class="org.apache.log4j.RollingFileAppender">
    <param name="File" value="${oracle.j2ee.home}/log/sdp/badmsg/badmsg.log" />
    <param name="Append" value="true" />
    <param name="Encoding" value="UTF-8" />
    <param name="MaxFileSize" value="100000KB" />
    <param name="MaxBackupIndex" value="10" />

    <layout class="org.apache.log4j.PatternLayout">
      <param name="ConversionPattern"
        value="%d{ISO8601} %-5p [%c{1}] (%t:%x) %m%n" />
    </layout>
  </appender>

  <!-- ============================== -->
  <!-- A size based rolling appender -->
  <!-- ============================== -->
  <appender name="CONFIG_FILE_LOG" class="org.apache.log4j.RollingFileAppender">
    <param name="File" value="${oracle.j2ee.home}/log/sdp/config/config.log" />
    <param name="Append" value="true"/>
    <param name="Encoding" value="UTF-8" />
    <param name="MaxFileSize" value="500KB"/>
    <param name="MaxBackupIndex" value="2"/>

    <layout class="org.apache.log4j.PatternLayout">
      <param name="ConversionPattern"
        value="%d{yyyy-MM-dd HH:mm:ss,SSSZ} [%c{1}] %m%n" />
    </layout>   
  </appender>

  <!-- ============================== -->
  <!-- A size based rolling appender -->
  <!-- ============================== -->
  <appender name="STATISTICS_FILE_LOG" class="org.apache.log4j.RollingFileAppender">
    <param name="File" value="${oracle.j2ee.home}/log/sdp/statistics/statistics.log" />
    <param name="Append" value="true" />
    <param name="Encoding" value="UTF-8" />
    <param name="MaxFileSize" value="100000KB" />
    <param name="MaxBackupIndex" value="10" />

    <layout class="org.apache.log4j.PatternLayout">
      <param name="ConversionPattern"
        value="%d{yyyy-MM-dd HH:mm:ss,SSSZ} %m%n" />
    </layout>
  </appender>

  <!-- ============================== -->
  <!-- A size based rolling appender -->
  <!-- ============================== -->
 <appender name="STATISTICS_FORMAT_FILE_LOG" class="org.apache.log4j.RollingFileAppender">
    <param name="File" value="${oracle.j2ee.home}/log/sdp/statistics/statistics.log" />
    <param name="Append" value="true" />
    <param name="Encoding" value="UTF-8" />
    <param name="MaxFileSize" value="100000KB" />
    <param name="MaxBackupIndex" value="10" />

    <layout class="org.apache.log4j.PatternLayout">
      <param name="ConversionPattern"
        value="%m%n" />
    </layout>
  </appender>

  <!-- ============================== -->
  <!-- A size based rolling appender -->
  <!-- ============================== -->
  <appender name="EVENTLOGGER_FILE_SIZE"
    class="org.apache.log4j.RollingFileAppender">
    <param name="File" value="${oracle.j2ee.home}/log/sdp/events.log" />
    <param name="Append" value="true" />
    <param name="Encoding" value="UTF-8" />
    <param name="MaxFileSize" value="100000KB" />
    <param name="MaxBackupIndex" value="10" />
    <layout class="oracle.sdp.eventlogger.BasicLayout"></layout>
  </appender>

  <!-- ============================== -->
  <!-- Append messages to the console -->
  <!-- ============================== -->
  <appender name="CONSOLE" class="org.apache.log4j.ConsoleAppender">
    <param name="Threshold" value="ERROR" />
    <param name="Encoding" value="UTF-8" />
    <layout class="org.apache.log4j.PatternLayout">
      <param name="ConversionPattern"
        value="%d{yyyy-MM-dd HH:mm:ss,SSSZ} %-5p [%c{1}] %m%n" />
    </layout>
  </appender>

  <!-- ============================== -->
  <!-- Append to TCP SOCKET -->
  <!-- ============================== -->
  <appender name="SYSTEM_SOCKET"
    class="org.apache.log4j.net.SocketAppender">
    <param name="RemoteHost" value="127.0.0.1" />
    <param name="Port" value="4477" />
    <param name="Threshold" value="DEBUG" />
  </appender>

  <!-- ============================== -->
  <!-- Syslog events                  -->
  <!-- ============================== -->
  <appender name="TRAFFIC_SYSLOG"
    class="org.apache.log4j.net.SyslogAppender">
    <param name="Threshold" value="INFO" />
    <param name="Facility" value="LOCAL1" />
    <!-- param name="FacilityPrinting" value="false"/ -->
    <param name="SyslogHost" value="127.0.0.1" />
    <layout class="org.apache.log4j.PatternLayout">
      <param name="ConversionPattern"
        value="%d{yyyy-MM-dd HH:mm:ss,SSSZ} %-5r %-5p [%c] (%t:%x) %m%n" />
    </layout>
  </appender>

  <!-- ============================== -->
  <!-- Syslog events                   -->
  <!-- ============================== -->
  <appender name="SYSTEM_SYSLOG"
    class="org.apache.log4j.net.SyslogAppender">
    <param name="Threshold" value="ERROR" />
    <param name="Facility" value="LOCAL0" />
    <!-- param name="FacilityPrinting" value="false"/ -->
    <param name="SyslogHost" value="127.0.0.1" />
    <layout class="org.apache.log4j.PatternLayout">

        <param name="ConversionPattern"
        value="%d{yyyy-MM-dd HH:mm:ss,SSSZ} %-5r %-5p [%c] (%t:%x) %m%n" />
    </layout>
  </appender>

  <!-- ============================== -->
  <!-- Syslog events                   -->
  <!-- ============================== -->
  <appender name="EVENTLOGGER_SYSLOG"
    class="org.apache.log4j.net.SyslogAppender">
    <param name="Threshold" value="ALL" />
    <param name="Facility" value="LOCAL2" />
    <!-- param name="FacilityPrinting" value="false"/ -->
    <param name="SyslogHost" value="127.0.0.1" />
    <layout class="oracle.sdp.eventlogger.BasicLayout"></layout>
  </appender>

Оригинал
Полезная статья о сути appender-ов
Простой и понятный пример настройки