Micrometer tracing과 correlation ID는 한 요청을 어떻게 찾을까요?

spring:
  application:
    name: order-api

management:
  tracing:
    sampling:
      probability: 1.0
  opentelemetry:
    tracing:
      export:
        otlp:
          endpoint: "http://localhost:4318/v1/traces"

package com.example.order;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;

@Service
public class OrderService {

    private static final Logger log = LoggerFactory.getLogger(OrderService.class);

    public void placeOrder() {
        log.info("payment approval started");
    }
}

logging:
  pattern:
    correlation: "[${spring.application.name:},%X{traceId:-},%X{spanId:-}] "
  include-application-name: false

logging:
  structured:
    format:
      console: logstash

package com.example.order;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import org.springframework.stereotype.Component;

@Component
public class OrderProcessor {

    private static final Logger log = LoggerFactory.getLogger(OrderProcessor.class);

    public void process(String orderId) {
        try (MDC.MDCCloseable ignored = MDC.putCloseable("orderId", orderId)) {
            log.info("order processing started");
        }
    }
}

package com.example.order;

import org.springframework.stereotype.Component;
import org.springframework.web.client.RestClient;

@Component
public class PaymentClient {

    private final RestClient restClient;

    public PaymentClient(RestClient.Builder builder) {
        this.restClient = builder
                .baseUrl("http://payment-api:8080")
                .build();
    }

    public void approve(String orderId) {
        this.restClient.post()
                .uri("/payments/{orderId}", orderId)
                .retrieve()
                .toBodilessEntity();
    }
}

package com.example.order;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.task.support.ContextPropagatingTaskDecorator;

@Configuration(proxyBeanMethods = false)
public class ContextPropagationConfig {

    @Bean
    ContextPropagatingTaskDecorator contextPropagatingTaskDecorator() {
        return new ContextPropagatingTaskDecorator();
    }
}

package com.example.order;

import io.micrometer.observation.Observation;
import io.micrometer.observation.ObservationRegistry;
import org.springframework.stereotype.Component;

@Component
public class InventoryAllocator {

    private final ObservationRegistry observationRegistry;

    public InventoryAllocator(ObservationRegistry observationRegistry) {
        this.observationRegistry = observationRegistry;
    }

    public void allocate(String channel) {
        Observation.createNotStarted("inventory.allocate", this.observationRegistry)
                .lowCardinalityKeyValue("channel", channel)
                .observe(this::allocateInventory);
    }

    private void allocateInventory() {
        // 재고 할당 규칙을 실행해요.
    }
}