How to drop spans

[cdvv7788]

I have a couple points in my system where I have consumers that hit a queue until it has something to consume (no long polling, a very frequent polling). Implementation improvements aside, I would like to know if there is a way to discard some span and it's children generated with auto-instrumentations in situations like this. Something along the lines of:

with tracer.start_as_current_span("my-span", noop=True):
    ...

I want to prevent useless traces from being sent at all, including its children. Why add a parent trace instead of preventing the span creation on automatic instrumentations? Because auto-instrumentations are still kind of limited, with database instrumentations lacking any mechanism to avoid creating spans.

Is this possible at the moment?

[lzchen]

@cdvv7788
Just to clarify, you want to have the option of not collecting telemetry for certain instrumentations, on a per request basis? Or do you just care about not exporting the telemetry?

If the former, you can create a custom Sampler that reads some attribute of the request and creates a no-op span based off that logic.

If the latter, you can create a custom SpanProcessor that drops the span before exporting based off of some custom logic.

[adriangb]

I do still think it would be nice to have a way to set a span to not be recording. Something like span.discard().