fix: open-telemetry#1690

Author: TommyCpp

examples/broken_traces/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "broken_traces"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+opentelemetry = "0.22.0"
+opentelemetry-stdout = { version = "0.3.0", features = ["trace"] }
+opentelemetry_sdk = "0.22.1"
+serde_json = "1.0.116"
+tracing = "0.1.40"
+tracing-opentelemetry = "0.23.0"
+tracing-subscriber = "0.3.18"

examples/broken_traces/src/main.rs

@@ -0,0 +1,53 @@
+use opentelemetry::{
+    trace::{Span, Tracer, TracerProvider as _},
+    KeyValue,
+};
+
+use opentelemetry_sdk::{
+    resource,
+    trace::{config, Config, TracerProvider},
+    Resource,
+};
+use opentelemetry_stdout::SpanExporterBuilder;
+use tracing::span;
+use tracing_opentelemetry::OpenTelemetrySpanExt;
+use tracing_subscriber::{layer::SubscriberExt, Registry};
+
+fn main() {
+    println!("Hello, world!");
+    let stdout_exporter = SpanExporterBuilder::default()
+        .with_encoder(|writer, data| {
+            serde_json::to_writer_pretty(writer, &data).unwrap();
+            Ok(())
+        })
+        .build();
+    let provider = TracerProvider::builder()
+        .with_config(Config::default().with_resource(Resource::new(vec![])))
+        .with_simple_exporter(stdout_exporter)
+        .build();
+    let tracer = provider.tracer("tracing-opentelemetry");
+    let telemetry = tracing_opentelemetry::layer().with_tracer(tracer);
+    let subscriber = Registry::default().with(telemetry);
+
+    tracing::subscriber::with_default(subscriber, || {
+        let tracer = provider.tracer("otel-tracing");
+
+        // this is the root span created using tokio tracing api
+        let root = span!(tracing::Level::TRACE, "tokio-tracing-span-parent");
+        let _enter = root.enter();
+
+        // this is a child span created using tokio tracing api
+        // this correctly parented to the root span
+        let child = span!(tracing::Level::TRACE, "tokio-tracing-span-child");
+        let _enter_child = child.enter();
+
+        // this is another child, created using otel tracing api
+        // but this is *NOT* parented to the above spans
+        // demonstrating broken traces when mixing and matching tracing and opentelemetry apis
+        // let mut span = tracer
+        //     .start_with_context("otel-tracing-span", &child.context());
+        let mut span = tracer
+            .start("otel-tracing-span");
+        span.end();
+    });
+}