Align Sampling API with specs

[lzchen]

Looks like Sampling "API' is actually defined as part of the SDK.

As well, there are some implementation details that are possibly deviating from the spec.
For example, spans set with is_recording_events to False are currently not even started/ended. According to the spec, it seems the spans should still be passed onto the processor but not the exporter (if is_sampled flag is set).

Also, the is_recording_events field seems to be always returning True as part of the SDK. We probably need this to be an actual property of the span.

[aravinsiva]

I can look into this if help is still needed.

[aabmass]

@lzchen, can Aravin take this or did you already start on it?

[lzchen]

@aravinsiva
Go for it! Thanks.

[aravinsiva]

To summarize what needs to be done:

• The Sampling API needs to be moved to the SDK
• And ensuring all corresponding methods meet the spec

Correct? Just want to be sure before I get working

[lzchen]

@aravinsiva
Yes seems about right.

[codeboten]

@aravinsiva are you still interested in taking this on? Just checking that you'll have enough time to work on it.

[aravinsiva]

Hi @codeboten I have done some work on it. However I have a time sensitive project being worked on right now. So if this is high priority perhaps reassigning it is best.

[lzchen]

open-telemetry/opentelemetry-specification#611

EDIT: Done.

[lzchen]

open-telemetry/opentelemetry-specification#610

EDIT: Done

[lzchen]

open-telemetry/opentelemetry-specification#881

[cijothomas]

To summarize what needs to be done:

• The Sampling API needs to be moved to the SDK
• And ensuring all corresponding methods meet the spec

Correct? Just want to be sure before I get working

the IsRecording of Span must be in the API.
the Sampled flag is part of SpanContext which is part of API.

The actual Samplers, ability to set samplers - part of SDK.

[lzchen]

Closed and opening individual issues in the future.