05快速学习了解 OpenTelemetry
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初使化::

    exp, err := jaeger.New(jaeger.WithCollectorEndpoint(jaeger.WithEndpoint(url)))


    optionBatcher := sdktrace.WithBatcher(exp)
    //// or:
    // batcher := tracesdk.NewBatchSpanProcessor(exp)
    // optionBatcher := tracesdk.WithSpanProcessor(batcher),

    optionSampler := sdktrace.WithSampler(sdktrace.ParentBased(sdktrace.TraceIDRatioBased(sampler)))

    resource := resource.NewSchemaless(semconv.ServiceNameKey.String(servicename)))
    //// or
    // resource := resource.NewWithAttributes(
    //   semconv.SchemaURL,
    //   semconv.ServiceNameKey.String(service),
    //   attribute.String("environment", environment),
    //   attribute.Int64("ID", id),
    // )
    optionResource := tracesdk.WithResource(resource)


    tp := sdktrace.NewTracerProvider(
        optionBatcher,
        optionSampler,
        optionResource
    )

    // 设置全局变量tp
    otel.SetTracerProvider(tp)
    // 设置全局变量propagator
    otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(
      propagation.TraceContext{}, propagation.Baggage{}))
    // 设置错误处理
    otel.SetErrorHandler(otel.ErrorHandlerFunc(func(e error) {
      log.Errorf("[otel] error: %v", err)
    }))


本服务使用::

    tr := otel.Tracer("<traceName>")
    _, span := tr.Start(ctx, spanName)
    span.SetAttributes(attribute.Key("<key>").String("<value>"))
    defer span.End()


其他服务初使化::

    requestMetadata, _ := metadata.FromIncomingContext(ctx)
    metadataCopy := requestMetadata.Copy()
    bags, spanCtx := opentelemetry.Extract(ctx, propagator, &metadataCopy)
    ctx = baggage.ContextWithBaggage(ctx, bags)
    tr := otel.Tracer(opentelemetry.TraceName)

    name, attr := opentelemetry.SpanInfo(info.FullMethod, opentelemetry.PeerFromCtx(ctx))

    ctx, span := tr.Start(trace.ContextWithRemoteSpanContext(ctx, spanCtx), name,
      trace.WithSpanKind(trace.SpanKindServer), trace.WithAttributes(attr...))
    defer span.End()