How to use serialized spancontext as parent, so that link can be established between two spans

[MacNale]

I want to recreate a spancontext serialized into a file. e.g

private static SpanContext createContext() {
    SpanContext remoteSpanContext = SpanContext.createFromRemoteParent("12345678876543211234567887654321",
        "8765432112345678", TraceFlags.getSampled(), TraceState.getDefault());

    return remoteSpanContext;
}

Once the SpanContext is created, I wish to use this as if it came from REMOTE service to create subsequent spans.

addLegacyServiceSpans(createContext());

private static void addLegacyServiceSpans(SpanContext spanContext) {
  OpenTelemetry openTelemetryParent = ExampleConfiguration.initOpenTelemetry("MYSERVICE");
  Tracer trace = openTelemetryParent.getTracer("MYTRACE");
  Span parentSpan = trace.spanBuilder("MYNEWOPERATION")
    .setStartTimestamp(Instant.now().toEpochMilli(), TimeUnit.MILLISECONDS)
    .startSpan();
}

I am not sure, how 'parentSpan' can use the passed 'spanContext' as remote span context.

[jkwatson]

context.with(Span.wrap(spanContext)) will get you a Context instance that can be used as the argument to the setParent(Context) call on the SpanBuilder.

[surajeetdev]

the traceIdhex and spanIdHex below is from upstream.

                    SpanContext spanContext = SpanContext.createFromRemoteParent(traceIdHex, spanIdHex, TraceFlags.getSampled(), TraceState.getDefault());
                    
                    logger.info("CreatedSpanContext with traceId {} spanId {} ",spanContext.getTraceId(),spanContext.getSpanId());
                    Span spanNoOp =Span.wrap(spanContext);
                    
                    OpenTelemetry telemetry = GlobalOpenTelemetry.get();
                    Tracer tracer= telemetry.getTracerProvider().get("tracifer");
                    
                    Span span = tracer.spanBuilder(String.valueOf("flatbuffer_deserializer")).setParent(Context.current().with(spanNoOp)).startSpan();                        
                    try (Scope scope = span.makeCurrent()){
                     
                    }finally {
                        span.end();
                    }

[jkwatson]

I did this locally and it seems to have worked as desired. You're not seeing the trace id of the span being the same as the trace id that you pass in on the spanContext?

Here is my code :

    String traceIdHex = TraceId.fromLongs(23434, 343434);
    String spanIdHex = SpanId.fromLong(2343434);
    SpanContext spanContext = SpanContext.createFromRemoteParent(traceIdHex, spanIdHex, TraceFlags.getSampled(), TraceState.getDefault());

    System.out.println("CreatedSpanContext with traceId " + spanContext.getTraceId() + " spanId " + spanContext.getSpanId());
    Span spanNoOp =Span.wrap(spanContext);

    Span span = tracer.spanBuilder("flatbuffer_deserializer").setParent(Context.current().with(spanNoOp)).startSpan();
    try (Scope scope = span.makeCurrent()){

    }finally {
      span.end();
    }

And the output (with a logging span exporter installed in the SDK):

CreatedSpanContext with traceId 0000000000005b8a0000000000053d8a spanId 000000000023c20a
INFO: 'flatbuffer_deserializer' : 0000000000005b8a0000000000053d8a 5bbdac2a4690ba28 INTERNAL [tracer: ConfigureTraceExample:] {}

[surajeetdev]

Actually i do se the traceid and spanId in the logs (printed from the SpanContext that was created) to be the same i used to create the SpanContext.

I guess the SpanExporter might be messing up , as i don't see it as child of remote in the Jaeger UI

[jkwatson]

The remote wrapped span you created will never by exported by this process. It is assumed that an upstream process has already exported it somewhere.

[ukrcoder]

Tried the same with quarkus 3.4.3 and latest opentelemetry and it didn't add the parent. Any info maybe anything is changed? The problem is I don't have header traceparent but I'm able to get it in cookies and invoke this code snippet inside filter.