Unable to integrate Uvicorn (multiple workers) to SigNoz.

[nitin1993915]

Bug description

*Below mentioned Docker CMDs work with single uvicorn worker to get the app traces but does not work with multiple uvicorn workers
["opentelemetry-instrument", "uvicorn", "app:app", "--host", "0.0.0.0", "--port", "8000"]
-- worked
["opentelemetry-instrument", "uvicorn", "app:app", "--host", "0.0.0.0", "--port", "8000", "--workers", `"2"]
-- did not work
*

Expected behavior

Should be able to check the traces on UI with multiple unicorn workers

[welcome]

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[pranay01]

@srikanthccv do you have insights on this?

[srikanthccv]

@nitin1993915 Which version of SDK are you using? Unlike gunicorn, uvicorn doesn't have any hooks that can be used to instantiate new span processor for each worker https://github.com/open-telemetry/opentelemetry-python/tree/main/docs/examples/fork-process-model. The newer version of sdk attempt to fix this to certain extent but there might be some limitation with uvicorn.

[pranay01]

@nitin1993915 Just checking if you are still facing this issue or this is solved. Please update here accordngly

[GokulNC]

Hi @pranay01

I am still facing this same when using multiple workers. With single worker, it works fine.
I installed SigNoz by cloning the repo today, and I was following this guide to setup SigNoz with FastAPI:
https://signoz.io/blog/opentelemetry-fastapi/

[srikanthccv]

You can get it to work using gunicorn + uvicorn.workers.UvicornWorker class but the uvicorn is directly not supported. Please follow up on the upstream repo for any updates open-telemetry/opentelemetry-python-contrib#385.