This is the version of ExSampling before it was made into a repo. (Source code.)
The root span of the trace is considered the head
. All children of the root span in the trace can be considered a tail
. We use the terms "head" and "tail" because of head-based sampling and tail-based sampling.
For these examples, we've set up the sample_hook
to drop any event (span) that contains the app.drop
field.