在日志中加上链路追踪示例

环境：

springboot + spring-cloud-starter-sleuth + logback

logback.xml示例：

<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="true" scanPeriod="10 seconds">
    <!--定义日志文件的存储地址 勿在 LogBack 的配置中使用相对路径-->
    <property name="LOG_HOME" value="./log" />
    <property name="APP_NAME" value="boot" />
    <!-- 控制台输出 -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%d{HH:mm:ss.SSS} [%X{traceId}-%X{X-B3-TraceId}] [%thread] %-5level %logger{50} - %msg%n</pattern>
        </encoder>
    </appender>
    <root level="INFO">
        <appender-ref ref="STDOUT" />
    </root>
    <!-- 按照每天生成日志文件 -->
    <appender name="FILE"  class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <FileNamePattern>${LOG_HOME}/%d{yyyy-MM-dd}/${APP_NAME}.%d{yyyy-MM-dd}.log</FileNamePattern>
            <MaxHistory>1</MaxHistory>
        </rollingPolicy>
        <encoder>
            <pattern>%d{HH:mm:ss.SSS} [%X{traceId}-%X{X-B3-TraceId}] [%thread] %-5level %logger{50} - %msg%n</pattern>
        </encoder>
    </appender>
    <appender name="ASYNC" class="ch.qos.logback.classic.AsyncAppender">
        <appender-ref ref="FILE" />
        <queueSize>512</queueSize>
        <discardingThreshold>0</discardingThreshold>
    </appender>
    <logger name="com.boot.core" level="info">
        <appender-ref ref="ASYNC" />
    </logger>
    <appender name="VISIT_LOG"  class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <FileNamePattern>${LOG_HOME}/%d{yyyy-MM-dd}/${APP_NAME}.%d{yyyy-MM-dd}.visit.log</FileNamePattern>
            <MaxHistory>1</MaxHistory>
        </rollingPolicy>
        <encoder>
            <pattern>%d{HH:mm:ss.SSS} [%X{traceId}-%X{X-B3-TraceId}] [%thread] %-5level %logger{50} - %msg%n</pattern>
        </encoder>
    </appender>
    <appender name="VISIT_ASYNC" class="ch.qos.logback.classic.AsyncAppender">
        <appender-ref ref="VISIT_LOG" />
        <queueSize>512</queueSize>
        <discardingThreshold>0</discardingThreshold>
    </appender>
    <logger name="com.boot.code" level="info">
        <appender-ref ref="VISIT_ASYNC" />
    </logger>
</configuration>

上面截图代码中logger标签中name属性可以包路径也可以是类路径，如果是包路径把该包下的所有打印的日志放到箭头所指的文件中，如果是类的全路径亦然。

其中的[%X{traceId}-%X{X-B3-TraceId}] 为链路追踪号：

 代码参考：https://github.com/Pinshuducha/boot