fix(tracing): Fix distributed tracing context linking (#2247)

crates/obs/src/telemetry/otel.rs

@@ -41,17 +41,17 @@ use crate::config::OtelConfig;
 use crate::global::set_observability_metric_enabled;
 use crate::telemetry::filter::build_env_filter;
 use crate::telemetry::guard::OtelGuard;
-// Import helper functions from local.rs (sibling module)
-use crate::TelemetryError;
 use crate::telemetry::local::spawn_cleanup_task;
 use crate::telemetry::recorder::Recorder;
 use crate::telemetry::resource::build_resource;
 use crate::telemetry::rolling::{RollingAppender, Rotation};
+// Import helper functions from local.rs (sibling module)
+use crate::TelemetryError;
 use metrics::counter;
-use opentelemetry::{global, trace::TracerProvider};
+use opentelemetry::{global, propagation::TextMapCompositePropagator, trace::TracerProvider};
 use opentelemetry_appender_tracing::layer::OpenTelemetryTracingBridge;
 use opentelemetry_otlp::{Compression, Protocol, WithExportConfig, WithHttpConfig};
-use opentelemetry_sdk::propagation::TraceContextPropagator;
+use opentelemetry_sdk::propagation::{BaggagePropagator, TraceContextPropagator};
 use opentelemetry_sdk::{
     logs::SdkLoggerProvider,
     metrics::{PeriodicReader, SdkMeterProvider},
@@ -326,7 +326,8 @@ pub(super) fn init_observability_http(
 ///
 /// Returns `None` when the endpoint is empty or trace export is disabled.
 /// When enabled, the provider is also registered as the global tracer provider
-/// and installs the W3C trace-context propagator.
+/// and installs a composite propagator supporting both W3C TraceContext
+/// (traceparent header) and W3C Baggage (baggage header) propagation.
 fn build_tracer_provider(
     trace_ep: &str,
     config: &OtelConfig,
@@ -358,7 +359,14 @@ fn build_tracer_provider(
 
     let provider = builder.build();
     global::set_tracer_provider(provider.clone());
-    global::set_text_map_propagator(TraceContextPropagator::new());
+
+    // Configure composite propagator to support multiple trace context formats:
+    // - W3C TraceContext (traceparent header) - standard format for distributed tracing
+    // - W3C Baggage (baggage header) - for propagating user-defined key-value pairs
+    let propagator =
+        TextMapCompositePropagator::new(vec![Box::new(TraceContextPropagator::new()), Box::new(BaggagePropagator::new())]);
+    global::set_text_map_propagator(propagator);
+
     Ok(Some(provider))
 }
 

rustfs/src/server/http.rs

@@ -35,6 +35,7 @@ use hyper_util::{
 };
 use metrics::{counter, histogram};
 use opentelemetry::global;
+use opentelemetry::trace::TraceContextExt;
 use rustfs_common::GlobalReadiness;
 use rustfs_config::{RUSTFS_TLS_CERT, RUSTFS_TLS_KEY};
 use rustfs_ecstore::rpc::{TONIC_RPC_PREFIX, verify_rpc_signature};
@@ -636,7 +637,7 @@ fn process_connection(
             .layer(
                 TraceLayer::new_for_http()
                     .make_span_with(|request: &HttpRequest<_>| {
-                        let trace_id = request
+                        let request_id = request
                             .headers()
                             .get(http::header::HeaderName::from_static("x-request-id"))
                             .and_then(|v| v.to_str().ok())
@@ -646,6 +647,18 @@ fn process_connection(
                             propagator.extract(&HeaderMapCarrier::new(request.headers()))
                         });
 
+                        // Log trace context extraction for debugging distributed tracing
+                        if parent_context.has_active_span() {
+                            let span_ref = parent_context.span();
+                            debug!(
+                                otel_trace_id = %span_ref.span_context().trace_id(),
+                                otel_parent_span_id = %span_ref.span_context().span_id(),
+                                sampled = span_ref.span_context().is_sampled(),
+                                "Extracted trace context from incoming request headers"
+                            );
+                        } else {
+                            debug!("No trace context found in request headers, will create root span");
+                        }
                         // Extract real client IP from trusted proxy middleware if available
                         let client_info = request.extensions().get::<ClientInfo>();
                         let real_ip = client_info
@@ -653,7 +666,7 @@ fn process_connection(
                             .unwrap_or_else(|| "unknown".to_string());
 
                         let span = tracing::info_span!("http-request",
-                            trace_id = %trace_id,
+                            request_id = %request_id,
                             status_code = tracing::field::Empty,
                             method = %request.method(),
                             real_ip = %real_ip,