The trace IDs are not being propagated.

[fleszarnatalia]

In what version(s) of Spring for Apache Kafka are you seeing this issue?
"3.3.7"

Describe the bug

When enabling tracing in Spring Kafka using the following configuration:

spring:
kafka:
template:
observation-enabled: true
listener:
observation-enabled: true

the trace IDs are not being propagated.

Description
The trace ID changes unexpectedly across different Kafka producer and consumer operations. Below is a sample log output demonstrating the issue:

2025-01-05T19:23:49.726+01:00 INFO 72749 --- [sample-service] [nio-8080-exec-1] [4b7ede1e7858060aeac5ffec1685171d-b03b1a50e75f9d99] c.b.b.c.g.ConfigurationsService
2025-01-05T19:23:49.922+01:00 INFO 72749 --- [sample-service] [ntainer#0-0-C-1] [28838532a77fd955681f83fbb0171a6c-134cd44f90cdb7ee] c.b.c.c.ConfigurationsConsumer

Notice the trace IDs:

[4b7ede1e7858060aeac5ffec1685171d-49e46abd74e60589] during producer initialization.
[28838532a77fd955681f83fbb0171a6c-134cd44f90cdb7ee] during consumer message processing.
The trace IDs do not remain consistent for operations that should belong to the same trace.

To Reproduce

Enable tracing with the configuration shown above.
Perform a Kafka producer operation, followed by a consumer operation.
Observe the logs and note the changing trace IDs.

Expected behavior

The trace ID should remain the same throughout the lifecycle of a trace, including producer creation, message publishing, consumer message processing, and downstream operations.

[artembilan]

I think with 3.3.7 you mean Spring Boot version.
Spring for Apache Kafka for that one is 3.2.6.

I don't think the producer creating phase is supposed to be included into some trace.
Usually that happens during Spring application startup.
However, I agree that producing and consuming has to be maintain the same trace.
That's exactly the whole point of the distributed tracing.

Would be great if you could share with us a simple project where we can reproduce the problem.

Thank you!

[artembilan]

Please, take a look into the sample I propose for the project code base: #3699.