9656d0afa7
* Bump versions in versions.yaml * Prepare stable-v1 for version v1.26.0 * Prepare experimental-metrics for version v0.48.0 * Prepare experimental-logs for version v0.2.0-alpha * Prepare experimental-schema for version v0.0.9 * Update CHANGELOG * Unbump experimental-schema * Update CHANGELOG.md Co-authored-by: Robert Pająk <pellared@hotmail.com> --------- Co-authored-by: Robert Pająk <pellared@hotmail.com> Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>
"Passthrough" setup for OpenTelemetry
Some Go programs may wish to propagate context without recording spans. To do this in OpenTelemetry, simply install TextMapPropagators, but do not install a TracerProvider using the SDK. This works because the default TracerProvider implementation returns a "Non-Recording" span that keeps the context of the caller but does not record spans.
For example, when you initialize your global settings, the following will propagate context without recording spans:
// Setup Propagators only
otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
But the following will propagate context and create new, potentially recorded spans:
// Setup SDK
exp, _ := stdout.New(stdout.WithPrettyPrint())
tp = sdktrace.NewTracerProvider(
sdktrace.WithBatcher(exp),
)
otel.SetTracerProvider(tp)
// Setup Propagators
otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
The Demo
The demo has the following call structure:
Outer -> Passthrough -> Inner
If all components had both an SDK and propagators registered, we would expect the trace to look like:
|-------outer---------|
|-Passthrough recv-|
|Passthrough send|
|---inner---|
However, in this demo, only the outer and inner have TracerProvider backed by the SDK. All components have Propagators set. In this case, we expect to see:
|-------outer---------|
|---inner---|