Propagate span-context for Kafka Clients by injecting and extracting in message headers

[mnottheone]

Right now, auto instrumentation records spans for Kafka clients, but context propagation is missing. Let me know if I am wrong and I tried running it myself and span-ids were missing in message headers.
Context propagation for Kafka clients was supported for opentracing using java-kafka-client . This is really helpful for applications involving Kafka.

Changes involved will be implementing inject and extract in TextMapPropagator. I can see explicitly only propagator's setter and getter are implemented in InjectAdapter and extractAdapter. Any specific reasons? Didn't find any blocker in OpenTelemetery API.

Can we add context propagation for kafka clients ?

I don't know the best way to get it done. But happy to learn and make a pull request.

[iNikem]

There is code in place to propagate trace context via kafka headers:

opentelemetry-java-instrumentation/instrumentation/kafka-clients-0.11/src/main/java/io/opentelemetry/instrumentation/auto/kafkaclients/KafkaProducerInstrumentation.java

Line 114 in 7969a83

OpenTelemetry.getPropagators()

If that does not work, then something is broken and we should investigate it. Can you confirm it does not work?

[mnottheone]

I tried in debug mode and can see traceparent ( traceId-spanId.. ) in headers. But issue is spans from producers and consumers are not getting stitched in Jaeger. There are separate Traces/spans for producer and consumer messages. It lead me to assumption that context in not propagated.

Can see no extract here

In java-kafka-client it's done here

[trask]

Hi @mnottheone! Kafka propagation works for me, can you provide a standalone repro so we can try it out and see what might be different for your case?

[mnottheone]

Hi! I tried replicating in standalone, it was working. I simply removed some extra code for JaegerTracer (Jaeger and OpenTracing libs) and it also started working. Thanks a lot for prompt responses. Closing this issue.

[vimal3271]

@mnottheone I am facing the same issue where the producer and consumer traces are reported separately . Is there any config that I need to tune ? I am using Jaeger (1.27) as backend.

[mateuszrzeszutek]

Hey @vimal3271 ,
Can you open a new issue with the details of your setup? What libraries you're using for accessing kafka, what versions etc. It would be awesome if you could provide a code example or a reproduction scenario/app too

[Samarth888]

Hi, I am experiencing a similar problem where I am getting separate traces for producer and consumer instead of a single flow. I am using auto instrumentation and using Zipkin backend. I have also checked through debug mode and ensured that the headers are present, so I am not able to analyze if this is a propagation issue or something else.

[carlos045]

I have the same issue @Samarth888 I get my http call in one trace nd producer in other trace o dont know what happen