Jaeger Exporter filters out links having a different link span id than the parent id

[shaicantor]

Please answer these questions before submitting a bug report.

What version of OpenTelemetry are you using?

@opentelemetry/[email protected]
@opentelemetry/[email protected]
@opentelemetry/[email protected]
@opentelemetry/[email protected]
@opentelemetry/[email protected]

What version of Node are you using?

16.11.1

Please provide the code you used to setup the OpenTelemetry SDK

tracing.js

const { getNodeAutoInstrumentations } = require("@opentelemetry/auto-instrumentations-node");
const { JaegerExporter } = require("@opentelemetry/exporter-jaeger");
const { SemanticResourceAttributes } = require('@opentelemetry/semantic-conventions');
const { Resource } = require('@opentelemetry/resources');
const { NodeTracerProvider } = require('@opentelemetry/sdk-trace-node');
const { BatchSpanProcessor, SimpleSpanProcessor } = require('@opentelemetry/sdk-trace-base');
const { registerInstrumentations } = require('@opentelemetry/instrumentation');
const {AwsInstrumentation} = require("@opentelemetry/instrumentation-aws-sdk");
const { CollectorTraceExporter } = require('@opentelemetry/exporter-collector');

const jaegerExporter = new JaegerExporter();
const tracerProvider = new NodeTracerProvider({
    resource: new Resource({
        [SemanticResourceAttributes.SERVICE_NAME]: JSON.parse(process.env.pm2_env)["SERVICE"]
    })
});

tracerProvider.addSpanProcessor(new SimpleSpanProcessor(jaegerExporter));
tracerProvider.register();
registerInstrumentations({
    tracerProvider: tracerProvider,
    instrumentations: [new AwsInstrumentation({}), getNodeAutoInstrumentations()],
});

What did you do?

• I provisioned an EC2 instance containing docker.
• Ran jaeger all-in-one - docker run -d -e COLLECTOR_ZIPKIN_HOST_PORT=:9411 -p 5775:5775/udp -p 6831:6831/udp -p 6832:6832/udp -p 5778:5778 -p 16686:16686 -p 14268:14268 -p 14269:14269 -p 14250:14250 -p 9411:9411 jaegertracing/all-in-one:local
• started my node.js applications using pm2 using --require tracing.js (the file from above)
• In my architecture I have a producer sending messages to SQS and a consumer receiving messages from SQS.

What did you expect to see?

• The instrumentation-aws-sdk implements parent child schemas according to the spec here

Process P: | Span Prod1 | Span Prod2 |
--
Process C:                      | Span Recv1 |
                                        | Span Proc1 |
                                               | Span Proc2 |

Field or Attribute	Span Prod1	Span Prod2	Span Recv1	Span Proc1	Span Proc2
Span name	"Q send"	"Q send"	"Q receive"	"Q process"	"Q process"
Parent				Span Recv1	Span Recv1
Links				Span Prod1	Span Prod2
SpanKind	PRODUCER	PRODUCER	CONSUMER	CONSUMER	CONSUMER
Status	Ok	Ok	Ok	Ok	Ok
net.peer.name	"ms"	"ms"	"ms"	"ms"	"ms"
net.peer.port	1234	1234	1234	1234	1234
messaging.system	"rabbitmq"	"rabbitmq"	"rabbitmq"	"rabbitmq"	"rabbitmq"
messaging.destination	"Q"	"Q"	"Q"	"Q"	"Q"
messaging.destination_kind	"queue"	"queue"	"queue"	"queue"	"queue"
messaging.operation			"receive"	"process"	"process"
messaging.message_id	"a1"	"a2"		"a1"	"a2"

• From the table above, following a conversation with @blumamir in this issue, I expected to see a reference in jaeger (link in open telemetry) from Span Proc1 to Span Prod1 but I didn't.
• As you can see Span Proc1 can have 1 parent (Span Recv1) but a link to a different span (in a different trace), but this code, I suspect enforces otherwise - https://github.com/open-telemetry/opentelemetry-js/blob/main/packages/opentelemetry-exporter-jaeger/src/transform.ts#L127

function spanLinksToThriftRefs(
  links: Link[],
  parentSpanId?: string
): ThriftReference[] {
  return links
    .map((link): ThriftReference | null => {
      if (link.context.spanId === parentSpanId) {
        const refType = ThriftReferenceType.FOLLOWS_FROM;
        const traceId = link.context.traceId;
        const traceIdHigh = Utils.encodeInt64(traceId.slice(0, 16));
        const traceIdLow = Utils.encodeInt64(traceId.slice(16));
        const spanId = Utils.encodeInt64(link.context.spanId);
        return { traceIdLow, traceIdHigh, spanId, refType };
      }
      return null;
    })
    .filter(ref => !!ref) as ThriftReference[];
}

To test it, I removed the condition and got this which is what I expected.

What did you see instead?

I saw a span without the reference to the desired span in a different trace.

Additional context

[blumamir]

reference to the expected behavior in specification:
https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/sdk_exporters/jaeger.md#links

I think we need to revisit this code and identify implementation gaps from the spec