[BUG]: Celery "on_error" Task not showing in DataDog Metrics

[clicktravel-antonrand]

Tracer Version(s)

2.7.0

Python Version(s)

Python 3.11.12

Pip Version(s)

pip 24.0

Bug Report

Hello,

Given the Reproduction code, I would expect to see a DataDog metric for the on_booking_error Celery task which is ran inside a parent task.

I don't see any metrics for this task though, despite seeing logs in DataDog showing it has ran (though I see metrics for the parent task).

Should DD Trace send metrics for the on_error callback task or do I need to do it manually?

Reproduction Code

tasks = [
    book_item.signature(
        args=[],
        immutable=True,
    )
    for item in booking_items
]

booking_finished_callback = on_booking_finished.s()

all_booking_tasks = chord(tasks)

res = all_booking_tasks(
    booking_finished_callback.on_error(on_booking_error.s())
)

Error Logs

No response

Libraries in Use

celery==5.3.6

Operating System

No response

[wantsui]

Thanks for the report!

I have a reproduction of this based on the details that you shared: #13812 and from reading the Celery docs more on how this is used: https://docs.celeryq.dev/en/latest/userguide/canvas.html .

I will sync with my team next week to see if this is something we can easily add, but in the meantime, if visibility is urgent - custom instrumentation work (which can be seen in my test PR): https://docs.datadoghq.com/tracing/trace_collection/custom_instrumentation/python/dd-api/?tab=decorator

It's just if you want to add errors, you will also need to follow the errors example.

Though I understand if you want to wait until when we study this behavior further to assess how we can implement this correctly!