Tracing

分布式链路追踪示例。

完整示例代码：juice-samples

1.添加依赖

首先，添加juice-spring-boot-starter依赖：

<dependency>
    <groupId>io.infinityclub</groupId>
    <artifactId>juice-spring-boot-starter</artifactId>
    <version>1.0.0</version>
</dependency>

2.增加配置项

application.yml增加如下配置：

# juice
juice:
  tracing:
    enable: true
    pathPatterns: /api/*

应用启动后，juice-spring-boot-starter会自动注入juice.tracing.filter.TracingFilter，接口响应头会出现 X-TraceId。

如果希望RestTemplate发送请求时自动携带traceId和spanId，可以在RestTemplate上加上@DistributedTracing，如下：

import juice.tracing.annotation.DistributedTracing;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;

@Configuration
public class RestTemplateConfig {

    @DistributedTracing
    @Bean
    public RestTemplate restTemplate() {
        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
        factory.setReadTimeout(30000);//单位为ms
        factory.setConnectTimeout(20000);//单位为ms

        return new RestTemplate(factory);
    }

}

3.ELK + Logback

如果项目中使用的是logback日志框架，只需要在logback-spring.xml 加上相应配置即可在日志中输出TraceId。

完整logback-spring.xml示例：

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <property name="projectName" value="@project.artifactId@" />
    <property name="LOG_LEVEL" value="INFO" />
    <property name="LOG_PATH" value="logs/${projectName}"/>
    <property name="LOG_FILE_NAME" value="${projectName}"/>
    <property name="LOG_PATTERN" value="%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] [%X{X-TraceId}] %-5level %logger - %msg%n"/>
    <property name="LOG_STASH_HOST" value="10.10.37.2:5045" />

    <!--配置规则类的位置-->
    <conversionRule conversionWord="ip" converterClass="juice.core.logback.IPLogConfig" />
    <appender name="LOGSTASH" class="net.logstash.logback.appender.LogstashTcpSocketAppender">
        <destination>${LOG_STASH_HOST}</destination>
        <keepAliveDuration>5 minutes</keepAliveDuration>
        <writeBufferSize>81920</writeBufferSize>
        <encoder charset="UTF-8" class="net.logstash.logback.encoder.LoggingEventCompositeJsonEncoder">
            <providers>
                <timestamp/>
                <version/>
                <pattern>
                    <pattern>
                        <!-- ${hostIp}是应用服务所在系统IP，${prodName} 是服务项目名称 ，需要提前配置logback变量；这些格式是固定的，如果需要调整，需要提前沟通 -->
                        {"host": "%ip","project": "${projectName}","log_level": "%level","trace": "%X{X-TraceId:-}","span": "%X{X-SpanId:-}","parent": "%X{X-ParentSpanId:-}","thread": "%thread","class": "%logger","message": "%msg","exception_stack": "%ex{full}"}
                    </pattern>
                </pattern>
            </providers>
        </encoder>
    </appender>

    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
            <fileNamePattern>${LOG_PATH}/${LOG_FILE_NAME}-%d{yyyy-MM-dd}.%i.log</fileNamePattern>
            <maxFileSize>500MB</maxFileSize>
            <maxHistory>7</maxHistory>
            <totalSizeCap>4GB</totalSizeCap>
        </rollingPolicy>
        <encoder>
            <pattern>${LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>${LOG_PATTERN}</pattern>
            <charset>UTF-8</charset>
        </encoder>
    </appender>

    <!--async appender-->
    <appender name ="asyncLogStash" class= "ch.qos.logback.classic.AsyncAppender">
        <discardingThreshold >0</discardingThreshold>
        <queueSize>256</queueSize>
        <appender-ref ref ="LOGSTASH"/>
    </appender>

    <appender name ="asyncFile" class= "ch.qos.logback.classic.AsyncAppender">
        <discardingThreshold >0</discardingThreshold>
        <queueSize>256</queueSize>
        <appender-ref ref ="FILE"/>
    </appender>

    <appender name ="asyncConsole" class= "ch.qos.logback.classic.AsyncAppender">
        <discardingThreshold >0</discardingThreshold>
        <queueSize>128</queueSize>
        <appender-ref ref ="CONSOLE"/>
    </appender>

    <root level="${LOG_LEVEL}">
        <appender-ref ref="asyncLogStash"/>
        <appender-ref ref="asyncFile"/>
        <appender-ref ref="asyncConsole"/>
    </root>

    <logger name="juice" level="DEBUG" />

</configuration>