Tags provided in config are missing in traces while using OpenTracing

[nairiti-sharma]

Environment Details

• Helidon Version: 3.2.2
• Helidon SE
• JDK version: JDK 17

While using OpenTracing on 3.2.2, we observed that tags set in config files do not appear in the traces collected. In case of Open Telemetry , this works fine.

While creating spanBuilder in OpenTelemetryTracer, the following is used.

@Override
public Span.Builder<?> spanBuilder(String name) {
    OpenTelemetrySpanBuilder builder = new OpenTelemetrySpanBuilder(delegate.spanBuilder(name));
    tags.forEach(builder::tag);
    return builder;
}

But, in case of OpenTracingTracer, it is as below, where setting the tag part is missing (tags.forEach(builder::tag);)

public Span.Builder<?> spanBuilder(String name) {
    return new OpenTracingSpanBuilder(delegate, delegate.buildSpan(name));
}

[dalexandrov]

Hello,
can you please provide more details?
I have created a sample Helidon SE project with OpenTracing and Zipkin, and it works ok:

The config is:

tracing:
  service: "helidon-service"
  tags:
    tag1: "tag1-value"
    tag2: "tag2-value"

[vasanth-bhat]

Thanks, Tried out sample, sending traces to "jaeger-all-in-one"
There is one difference.

In case of. "helidon-tracing-jaeger", the tracer tags from config show up as Process tags

[vasanth-bhat]

With "helidon-tracing-zipkins" , these show up as regular Span tags, and not under Process (Tracer Tags)

[tjquinno]

Closing this issue: works as designed.

TL;DR - The Zipkin data model does not support trace-level (also known as process-level) tags, although Jaeger and the Helidon tracing API do. To preserve trace-level tags in the only way available, the Helidon adapter for Zipkin adds them to each span. That is why the U/I distinguishes between process and span tags for Jaeger but not for Zipkin.

Zipkin doc of their data model Scroll down to the Model section and expand Trace. It consists only of a list of spans; there are no tags at the trace level (or under Endpoint which might have been another option).

To create an example:

Prep

1. Start with the Helidon SE QuickStart app.

2. Add the following to application.yaml:

   tracing:
     service: "test-my-app"
     enabled: true
     sample-type: "const"
     sample-param: 1
     propagation: [ "jaeger", "b3_single", "w3c" ]
     span-processor-type: simple
     tags:
       tag1: "tag1-value"  # JAEGER_TAGS
       tag2: "tag2-value"  # JAEGER_TAGS
     boolean-tags:
       tag3: true          # JAEGER_TAGS
       tag4: false         # JAEGER_TAGS
     int-tags:
       tag5: 145           # JAEGER_TAGS
       tag6: 741           # JAEGER_TAGS
   

3. Add the following to pom.xml:

       <dependency>
           <groupId>io.helidon.tracing</groupId>
           <artifactId>helidon-tracing</artifactId>
       </dependency>
       <dependency>
           <groupId>io.helidon.tracing</groupId>
           <artifactId>helidon-tracing-jaeger</artifactId>
       </dependency>
   <!--    <dependency> -->
   <!--        <groupId>io.helidon.tracing</groupId> -->
   <!--        <artifactId>helidon-tracing-zipkin</artifactId> -->
   <!--    </dependency> -->
   

4. In the GreetService class change the body of the getDefaultMessageHandler method to this:

   Tracer tracer = request.context().get(Tracer.class).orElse(Tracer.global());
   Span.Builder<?> spanBuilder = tracer.spanBuilder("anon-greeting").tag("sp1", "val1");
   request.context().get(SpanContext.class).ifPresent(spanBuilder::parent);
   Span span = spanBuilder.start();
   try (Scope scope = span.activate()) {
       sendResponse(response, "World");
       span.end();
   } catch (Exception ex) {
       span.end(ex);
   }
   

5. Start Jaeger and Zipkin locally.

   • Jaeger - see Jaeger getting started page for directions
   • Zipkin - see [Zipkin quick start page] https://zipkin.io/pages/quickstart for directions

Try with Jaeger

1. Build and run the Helidon QuickStart SE app you modified.

2. Access the default greeting endpoint: curl http://localhost:8080/greet

3. Browse to http://localhost:16686, the Jaeger U/I.

4. From the Services droplist select test-my-app (that is the tracing service name in application.yaml).

5. Click the Find Traces button, then click the top trace row, then click the anon-greeting span.

   The Tags display shows (among others) sp1=val1 which is a span-level tag assigned explicitly in the updated GreetService code. The Process display shows (among others) tag1=tag1-value (and tag2 and tag3) which are tracer-level tags assigned in the updated application.yaml in the tracing section.

6. Stop the quickstart app.

Try with Zipkin

1. In the dependencies you added to pom.xml comment out the one for Jaeger and uncomment the one for Zipkin.
2. Build and run the app again.
3. Browse to http://localhost:9411, the Zipkin U/I.
4. Click the Run Query button, then click the SHOW button next to the trace it displays.
5. Click the up-arrow near the upper left of the window which expands to show the child spans.
6. the top span, then click the + sign next to the trace.
7. Click the anon-greeting span, then click SHOW ALL ANNOTATIONS button.
8. The Tags list includes both the tracer-level tags (tag1, tag2, etc.) and the span-level tag (sp1).