Tomcat原生日志长期运行可能导致硬盘被耗尽，影响系统运行，本文讨论对Tomcat日志的绕接方案，使用log4j三方件的能力接管Tomcat日志能力从而实现绕接。

把需要jar包复制到tomcat lib

主要涉及下面三个包：

log4j-api-2.3.jar log4j-core-2.3.jar log4j-jul-2.3.jar

设置环境变量

编辑setenv.sh

#!/bin/sh
export  "CLASSPATH=$CLASSPATH:$CATALINA_HOME/lib/log4j-jul-2.3.jar:$CATALINA_HOME/lib/log4j-api-2.3.jar:$CATALINA_HOME/lib/log4j-core-2.3.jar"

export
 CATALINA_OPTS="$CATALINA_OPTS
 -Djava.util.logging.manager=org.apache.logging.log4j.jul.LogManager
 -Dlog4j.configurationFile=$CATALINA_HOME/conf/log4j2.xml"

编辑log4j2.xml

<?xml version="1.0" encoding="utf-8"?>
<Configuration status="info">
 <Properties>
   <Property name="logdir">${sys:catalina.base}/logs</Property>   
   <Property name="layout">%d [%t] %-5p %c-%m%n</Property> 
 </Properties> 
 <Appenders>   
   <Console name="CONSOLE" target="SYSTEM_OUT">     
     <PatternLayout pattern="${layout}"/>   
   </Console>   
   <RollingFile name="CATALINA"  fileName="${logdir}/catalina.log"       
 filePattern="${logdir}/catalina.%d{yyyy-MM-dd}.log.gz">     
     <PatternLayout pattern="${layout}"/>     
     <SizeBasedTriggeringPolicy size="50MB"/>     
     <!-- DefaultRolloverStrategy属性如不设置，则默认为最多同一文件夹下7个文件，这里设置了20-->     
     <DefaultRolloverStrategy max="20"/>   
   </RollingFile>   
   <RollingFile name="LOCALHOST" fileName="${logdir}/localhost.log" filePattern="${logdir}/localhost.%d{yyyy-MM-dd}-%i.log.gz">     
     <PatternLayout pattern="${layout}"/>     
     <SizeBasedTriggeringPolicy size="50MB"/>     
     <!-- DefaultRolloverStrategy属性如不设置，则默认为最多同一文件夹下7个文件，这里设置了20-->     
     <DefaultRolloverStrategy max="20"/>   
   </RollingFile>   
   <RollingFile name="ACCESSLOG" fileName="${logdir}/localhost_access.log"       
 filePattern="${logdir}/localhost_acess.%d{yyyy-MM-dd}-%i.log.gz">     
     <PatternLayout pattern="${layout}"/>     
     <SizeBasedTriggeringPolicy size="50MB"/>     
     <!-- DefaultRolloverStrategy属性如不设置，则默认为最多同一文件夹下7个文件，这里设置了20 -->     
     <DefaultRolloverStrategy max="20"/>
   </RollingFile> 
 </Appenders> 
 <Loggers>
    <Logger name="com.huawei.cloudsop.tomcat.api.log" level="debug" additivity="false">     
     <AppenderRef ref="ACCESSLOG"/>   
   </Logger>   
   <Logger name="org.apache.catalina.core.ContainerBase"   level="info"
 additivity="false">
     <AppenderRef ref="LOCALHOST"/>
   </Logger>
    <Root level="info">
     <AppenderRef ref="CATALINA"/>
   </Root>
 </Loggers>
</Configuration>

修改server.xml

<Valve className="com.xxx.tomcat.api.log.AccessLogValveExt"
 pattern="%h %l %u %t "%r" %s %b %{x-request-id}i"/>

编写绕接类AccessLogValveExt

package com.xxx.tomcat.api.log;

import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.valves.AccessLogValve;

import java.io.CharArrayWriter;

public class AccessLogValveExt extends AccessLogValve
{
    */**
     * The descriptive information about
this implementation.
     */
    *protected static final String *info *=
            "com.huawei.cloudsop.tomcat.api.log.AccessLogValveExt/1.0";

    private static final org.apache.juli.logging.Log accessLog =
            org.apache.juli.logging.LogFactory.getLog(AccessLogValveExt.class);

    // rewrite log func of
    public void log(CharArrayWriter message) {
        accessLog.info(message.toString());
    }

    @Override
    public void log(Request request, Response response, long time) {
        super.log(request, response, time);
    }

    public String getInfo() {
        return info;
    }

    @Override
    protected synchronized void open() {
        // do nothing
    }
}

大功告成