尽管SpringBoot能够在application.properties来配置一些日志相关的内容,但是针对一个比较复杂,或者是有着自己运维体系的应用,这是远远不够用的.所以拓展自己的日志配置文件是必须的,官方推荐的是使用logback-spring.xml直接覆盖

,那么参照源码里面的TestCase可能配置内容如下.

<configuration>
    <include resource="org/springframework/boot/logging/logback/base.xml" />

    <property name="LOG_PATH" value="XXX" />
    <property name="LOG_PATTEN" value="[%-5level] %date [%thread] [%logger{36}:%line] >>> %msg%n" />

    
    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <File>xxx.log</File>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <FileNamePattern>xxx.%d{yyyy-MM-dd}.log</FileNamePattern>
        </rollingPolicy>
        <encoder charset="UTF-8">
            <pattern>${LOG_PATTEN}</pattern>
        </encoder>
    </appender>
    
    <appender name="ERROR" class="xxx.basic.logger.appender.logback.HttpAppender">
        <url>http://xxx:8081/api/logSetting</url>
        <filter class="ch.qos.logback.classic.filter.LevelFilter">
            <level>ERROR</level>
            <OnMismatch>DENY</OnMismatch>
            <OnMatch>ACCEPT</OnMatch>
        </filter>
    </appender>

    <logger name="com.alibaba.druid" level="ERROR" />
    ....

    <root>
        <level value="INFO" />
        <appender-ref ref="FILE" />
        <appender-ref ref="ERROR" />
    </root>
</configuration>

突然有一天线上磁盘告警,一般挂载到根目录下的磁盘是不会被业务直接使用的所以比较小.于是找到是tmp目录下有个很奇葩的spring.log.4接近30G .看日志内容是某个业务放量,打开了一个日志开关.于是对该应用日志配置文件进行排查.确定没有该日志文件的直接配置.于是转向了框架默认.

查看了一下上面所述的配置文件所引用的内容.发现base.xml默认也是声明了一些log行为.


base.xml

<included>
    <include resource="org/springframework/boot/logging/logback/defaults.xml" />
    <property name="LOG_FILE" value="${LOG_FILE:-${LOG_PATH:-${LOG_TEMP:-${java.io.tmpdir:-/tmp}}}/spring.log}"/>
    <include resource="org/springframework/boot/logging/logback/console-appender.xml" />
    <include resource="org/springframework/boot/logging/logback/file-appender.xml" />
    <root level="INFO">
        <appender-ref ref="CONSOLE" />
        <appender-ref ref="FILE" />
    </root>
</included>

file-appender.xml

<included>
    <appender name="FILE"
        class="ch.qos.logback.core.rolling.RollingFileAppender">
        <encoder>
            <pattern>${FILE_LOG_PATTERN}</pattern>
        </encoder>
        <file>${LOG_FILE}</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
            <fileNamePattern>${LOG_FILE}.%i</fileNamePattern>
        </rollingPolicy>
        <triggeringPolicy
            class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
            <MaxFileSize>10MB</MaxFileSize>
        </triggeringPolicy>
    </appender>
</included>

虽然我们include了上述的文件也通用声明了name为FILE的appender,但是没有被重新定义.于是只能去掉.但是没有这个base.xml关于SpringBoot的相关的启动信息和运行时的其他信息便不会输出.于是看下了base.xml 所包含的另一个文件.

<!--
Default logback configuration provided for import, equivalent to the programmatic
initialization performed by Boot
-->

<included>
    <conversionRule conversionWord="clr" converterClass="org.springframework.boot.logging.logback.ColorConverter" />
    <conversionRule conversionWord="wex" converterClass="org.springframework.boot.logging.logback.WhitespaceThrowableProxyConverter" />
    <conversionRule conversionWord="wEx" converterClass="org.springframework.boot.logging.logback.ExtendedWhitespaceThrowableProxyConverter" />
    <property name="CONSOLE_LOG_PATTERN" value="${CONSOLE_LOG_PATTERN:-%clr(%d{yyyy-MM-dd HH:mm:ss.SSS}){faint} %clr(${LOG_LEVEL_PATTERN:-%5p}) %clr(${PID:- }){magenta} %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:-%wEx}}"/>
    <property name="FILE_LOG_PATTERN" value="%d{yyyy-MM-dd HH:mm:ss.SSS} ${LOG_LEVEL_PATTERN:-%5p} ${PID:- } --- [%t] %-40.40logger{39} : %m%n${LOG_EXCEPTION_CONVERSION_WORD:-%wEx}"/>

    <appender name="DEBUG_LEVEL_REMAPPER" class="org.springframework.boot.logging.logback.LevelRemappingAppender">
        <destinationLogger>org.springframework.boot</destinationLogger>
    </appender>

    <logger name="org.apache.catalina.startup.DigesterFactory" level="ERROR"/>
    <logger name="org.apache.catalina.util.LifecycleBase" level="ERROR"/>
    <logger name="org.apache.coyote.http11.Http11NioProtocol" level="WARN"/>
    <logger name="org.apache.sshd.common.util.SecurityUtils" level="WARN"/>
    <logger name="org.apache.tomcat.util.net.NioSelectorPool" level="WARN"/>
    <logger name="org.crsh.plugin" level="WARN"/>
    <logger name="org.crsh.ssh" level="WARN"/>
    <logger name="org.eclipse.jetty.util.component.AbstractLifeCycle" level="ERROR"/>
    <logger name="org.hibernate.validator.internal.util.Version" level="WARN"/>
    <logger name="org.springframework.boot.actuate.autoconfigure.CrshAutoConfiguration" level="WARN"/>
    <logger name="org.springframework.boot.actuate.endpoint.jmx" additivity="false">
        <appender-ref ref="DEBUG_LEVEL_REMAPPER"/>
    </logger>
    <logger name="org.thymeleaf" additivity="false">
        <appender-ref ref="DEBUG_LEVEL_REMAPPER"/>
    </logger>
</included>

它定义的是SpringBoot的默认logger.于是文章开头的logback-spring.xml便修改为

<configuration>
    <include resource="org/springframework/boot/logging/logback/defaults.xml" />
    ....
</configuration>

/tmp/spring.log.*的文件便不会再有日志输出.使用命令 【 >spring.log.4 】把文件内容置成空.然后再删除掉,问题解决.