logback totalSizeCap 无效和maxHistory无效解决

totalSizeCap 无效升级logbackjar包到1.1.8版本，最好升级到1.2.0版本，因为1.2.0解决了当文件总大小大于2G时不能自动删除旧文件的问题，因为源码中有个文件大小判断是错误的。

源自https://tidyko.com/posts/589711b0.html

maxHistory 无效，需要增加一个设置 <cleanHistoryOnStart>true</cleanHistoryOnStart>，在只有设置为true并且 maxHistory 不为零才能起效。

源自https://www.jianshu.com/p/d9c08785430a

所以修改后的配置应该是

<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
 
<rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
<!-- rollover daily -->
<fileNamePattern>${LOG_HOME}/consumer.%d{yyyy-MM-dd}.%i.log</fileNamePattern>
<!-- each file should be at most 100MB, keep 60 days worth of history, but at most 20GB -->
<maxFileSize>50MB</maxFileSize>
<maxHistory>30</maxHistory>
<totalSizeCap>2GB</totalSizeCap>
<cleanHistoryOnStart>true</cleanHistoryOnStart>
</rollingPolicy>
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
</encoder>
</appender>

最后的

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

不能少了，根据实际配置来，appender name = 后面的参数是啥，就在<appender-ref ref="" /> 写啥

例子：

修改前：

<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
    <fileNamePattern>${log.home}/ui/${loggingUserId}/mylog_user_%d{yyyy-MM-dd}.log</fileNamePattern>
    <MaxHistory>7</MaxHistory>
</rollingPolicy>

修改后（增加【<cleanHistoryOnStart>true</cleanHistoryOnStart>】这一行）：

<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
    <fileNamePattern>${log.home}/ui/${loggingUserId}/mylog_user_%d{yyyy-MM-dd}.log</fileNamePattern>
    <MaxHistory>7</MaxHistory>
    <cleanHistoryOnStart>true</cleanHistoryOnStart>
</rollingPolicy>