Tail Sampling on Opentelemetry Sidecar Collector

[Sayyadd]

Hi,
I couldn't find accurate answer on documentation, that's why I am asking here.
Question is: If I deploy opentelemetry collector in sidecar mode, is it possible to apply tail sampling on that collector or I should do it on gateway collector ?

[yurishkuro]

Tail sampling needs to collect all spans for a trace before making a decision. A sidecar collector would normally only see a subset of a trace, assuming you have a distributed system with many services and many sidecars. So yes, you need to do tail sampling in the last stage collector which accepts traffic already partitioned by trace IDs.

[Sayyadd]

Thank you @yurishkuro