Description
I'm thinking we may want to revise this, since it's a little complicated.
If you combine both, then yes, it will typically behave how you like. However, if your application is called by an upstream one you don't necessarily control, then it can be advantageous to omit the ParentBased composite sampler. The result is that you can sometimes end up with traces that have missing root spans, but the rest of your traces will be coherent and at the volume you care about. We've run into this several times with customers who do head sampling and it unfortunately means they have to pick one or the other. We've tried to get them to switch to tail-based sampling but they often can't.
I'm thinking of rolling that guidance out across all the languages, but if you agree, would you want to incorporate here, or handle orthogonally?
Originally posted by @cartermp in #3318 (comment)
We should also revisit the environmental variables description.