# logback 插件

使用maven或gradle引入toolkit依赖。

    <dependency>
         <groupId>org.apache.skywalking</groupId>
         <artifactId>apm-toolkit-logback-1.x</artifactId>
         <version>{project.release.version}</version>
     </dependency>

在logback.xml的Pattern部分中设置%tid

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.core.encoder.LayoutWrappingEncoder">
            <layout class="org.apache.skywalking.apm.toolkit.log.logback.v1.x.TraceIdPatternLogbackLayout">
                <Pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%tid] [%thread] %-5level %logger{36} -%msg%n</Pattern>
            </layout>
        </encoder>
    </appender>

使用MDC，在logback.xml的Pattern部分中设置%tid

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.core.encoder.LayoutWrappingEncoder">
            <layout class="org.apache.skywalking.apm.toolkit.log.logback.v1.x.mdc.TraceIdMDCPatternLogbackLayout">
                <Pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%X{tid}] [%thread] %-5level %logger{36} -%msg%n</Pattern>
            </layout>
        </encoder>
    </appender>

支持logback AsyncAppender（也支持MDC），不需要其他配置。请参阅下面的logback.xml演示。有关详细信息：Logback AsyncAppender

    <configuration scan="true" scanPeriod=" 5 seconds">
        <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
            <encoder class="ch.qos.logback.core.encoder.LayoutWrappingEncoder">
                <layout class="org.apache.skywalking.apm.toolkit.log.logback.v1.x.mdc.TraceIdMDCPatternLogbackLayout">
                    <Pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%X{tid}] [%thread] %-5level %logger{36} -%msg%n</Pattern>
                </layout>
            </encoder>
        </appender>
    
        <appender name="ASYNC" class="ch.qos.logback.classic.AsyncAppender">
            <discardingThreshold>0</discardingThreshold>
            <queueSize>1024</queueSize>
            <neverBlock>true</neverBlock>
            <appender-ref ref="STDOUT"/>
        </appender>
    
        <root level="INFO">
            <appender-ref ref="ASYNC"/>
        </root>
    </configuration>

当你使用-javaagent激活skywalking tracer后，logback将会输出traceId（如果存在的话）。如果tracer未激活，输出将是TID: N/A

# logstash logback 插件

使用maven或gradle引入toolkit依赖。

<dependency>
    <groupId>org.apache.skywalking</groupId>
    <artifactId>apm-toolkit-logback-1.x</artifactId>
    <version>${skywalking.version}</version>
</dependency>

设置logback.xml的LogstashEncoder

<encoder charset="UTF-8" class="net.logstash.logback.encoder.LogstashEncoder">
    <provider class="org.apache.skywalking.apm.toolkit.log.logback.v1.x.logstash.TraceIdJsonProvider">
    </provider>
</encoder>

在logback-spring.xml中将Logstash的 LoggingEventCompositeJsonEncoder 设置为自定义json格式

1.将%tid的转换器添加为的子节点

<!--add converter for %tid -->
    <conversionRule conversionWord="tid" converterClass="org.apache.skywalking.apm.toolkit.log.logback.v1.x.LogbackPatternConverter"/>

2.为自定义json格式添加json编码器

<encoder class="net.logstash.logback.encoder.LoggingEventCompositeJsonEncoder">
            <providers>
                <timestamp>
                    <timeZone>UTC</timeZone>
                </timestamp>
                <pattern>
                    <pattern>
                        {
                        "level": "%level",
                        "tid": "%tid",
                        "thread": "%thread",
                        "class": "%logger{1.}:%L",
                        "message": "%message",
                        "stackTrace": "%exception{10}"
                        }
                    </pattern>
                </pattern>
            </providers>
</encoder>