异构服务链路追踪

文中使用的框架和服务：

网关：Spring Cloud Gateway

服务上游：Spring Boot 3.5.1 Spring Cloud 2025.0.0.0（Java）

服务下游：Kratos 2.8.0（Go）

链路追踪工具：Zipkin

Demo 地址：https://github.com/deigmata-paideias/deigmata-paideias/trace-transfer

Zipkin 启动

services:

  zipkin:
    image: 'openzipkin/zipkin:latest'
    container_name: "spring-ai-alibaba-zipkin"
    ports:
      - '9411:9411'

docker compose up -d 浏览器访问 9411.

关键性配置

SCG

pom.xml

tracing 组件

<dependency>
    <groupId>io.micrometer</groupId>
    <artifactId>micrometer-tracing</artifactId>
</dependency>

<dependency>
    <groupId>io.micrometer</groupId>
    <artifactId>micrometer-tracing-bridge-brave</artifactId>
</dependency>

<dependency>
    <groupId>io.zipkin.reporter2</groupId>
    <artifactId>zipkin-reporter-brave</artifactId>
</dependency>

Gateway

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-webflux</artifactId>
</dependency>

<!-- Spring Cloud Gateway -->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-gateway-server-webflux</artifactId>
</dependency>

application.yml

management:
  endpoints:
    web:
      exposure:
        include: '*'
  endpoint:
    health:
      show-details: ALWAYS
    logfile:
      external-file: ./logs/${spring.application.name}/console.log
  tracing:
    enabled: true
    sampling.probability: 1.0
    propagation:
      type: w3c
  zipkin:
    tracing:
      endpoint: http://localhost:9411/api/v2/spans

user-service

pom.xml 和 application.yml 相同。

pom 差异：

openfeign 远程调用

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>

FeignB3HeaderInterceptorConfig.java

如果不配置此请求拦截，openfeign 在 rpc 调用时不会自动透传请求头。

@Configuration
public class FeignB3HeaderInterceptorConfig {

    @Bean
    public RequestInterceptor b3HeaderInterceptor() {
        return template -> {
            ServletRequestAttributes attrs = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
            if (attrs != null) {
                HttpServletRequest request = attrs.getRequest();
                String b3 = request.getHeader("traceparent");
                if (b3 != null) {
                    template.header("traceparent", b3);
                }
            }
        };
    }
}

OpenFeign Client

@FeignClient(name = "kratos-user-svc", url = "http://localhost:8000")
public interface UserAPI {

    @GetMapping(value = "/api/v1/user/{id}")
    User getUser(@PathVariable("id") String id);

}

主类添加 @EnableFeignClients 注解，开启 FeignClient。

Kratos

main.go

Zipkin Init.

func zipkinTrace() {

    exporter, _ := zipkin.New("http://localhost:9411/api/v2/spans")

    otel.SetTracerProvider(trace.NewTracerProvider(
       trace.WithBatcher(exporter),
       trace.WithSampler(trace.AlwaysSample()),
    ))
}

zipkingTrace 函数放在 wireApp 之前。否则会导致 trace 失败？

Zipkin trace 截图

其他问题

1. tracing.propagation.type: w3c 要写 w3c ，b3 会导致请求头传递失败，串联不起来链路？

   这可能和下面代码有关，初始化成 zipkin b3.

   otel.SetTracerProvider(trace.NewTracerProvider(
     trace.WithBatcher(exporter),
     trace.WithSampler(trace.AlwaysSample()),
   ))

2. OpenFeign 必须要手动转发 tracing header？

3. kratos http & grpc 中间件添加 tracing.Server()？