🔍 OpenTelemetry 트레이싱 예시 (Java)

import io.opentelemetry.api.OpenTelemetry;
import io.opentelemetry.api.trace.Span;
import io.opentelemetry.api.trace.Tracer;
import io.opentelemetry.context.Scope;
import io.opentelemetry.sdk.OpenTelemetrySdk;
import io.opentelemetry.sdk.trace.SdkTracerProvider;
import io.opentelemetry.sdk.trace.export.BatchSpanProcessor;
import io.opentelemetry.exporter.jaeger.JaegerGrpcSpanExporter;

public class OrderService {
    private final Tracer tracer;
    
    public OrderService(OpenTelemetry openTelemetry) {
        this.tracer = openTelemetry.getTracer("order-service");
    }
    
    public void processOrder(Order order) {
        // 스팬 생성
        Span span = tracer.spanBuilder("processOrder").startSpan();
        
        // 스팬에 속성 추가
        span.setAttribute("orderId", order.getId());
        span.setAttribute("customerId", order.getCustomerId());
        span.setAttribute("amount", order.getAmount());
        
        try (Scope scope = span.makeCurrent()) {
            // 재고 확인
            checkInventory(order);
            
            // 결제 처리
            processPayment(order);
            
            // 배송 준비
            prepareShipment(order);
            
            span.addEvent("Order processed successfully");
        } catch (Exception e) {
            span.recordException(e);
            span.setStatus(StatusCode.ERROR, e.getMessage());
            throw e;
        } finally {
            span.end();
        }
    }
    
    private void checkInventory(Order order) {
        Span span = tracer.spanBuilder("checkInventory")
            .setParent(Context.current().with(Span.current()))
            .startSpan();
        
        try (Scope scope = span.makeCurrent()) {
            // 재고 확인 로직
            // ...
        } finally {
            span.end();
        }
    }
    
    // 다른 메서드들도 유사하게 구현
}