fix(telemetry): don't include metric events in spans

.changesets/fix_bnjjj_filter_metric_events.md

@@ -0,0 +1,5 @@
+### Don't include metric events in spans ([PR #5649](https://github.com/apollographql/router/pull/5649))
+
+Previously some internal metric events were included in traces and spans. This PR remove this noise.
+
+By [@bnjjj](https://github.com/bnjjj) in https://github.com/apollographql/router/pull/5649

apollo-router/src/plugins/telemetry/otel/layer.rs

@@ -42,6 +42,7 @@ use crate::plugins::telemetry::consts::OTEL_STATUS_CODE;
 use crate::plugins::telemetry::consts::OTEL_STATUS_MESSAGE;
 use crate::plugins::telemetry::consts::REQUEST_SPAN_NAME;
 use crate::plugins::telemetry::consts::ROUTER_SPAN_NAME;
+use crate::plugins::telemetry::formatters::filter_metric_events;
 use crate::plugins::telemetry::reload::IsSampled;
 use crate::plugins::telemetry::reload::SampledSpan;
 use crate::plugins::telemetry::reload::SPAN_SAMPLING_RATE;
@@ -960,6 +961,10 @@ where
     /// [`ERROR`]: tracing::Level::ERROR
     /// [`Error`]: opentelemetry::trace::StatusCode::Error
     fn on_event(&self, event: &Event<'_>, ctx: Context<'_, S>) {
+        // Don't include deprecated metric events
+        if !filter_metric_events(event) {
+            return;
+        }
         // Ignore events that are not in the context of a span
         if let Some(span) = ctx.lookup_current() {
             let mut extensions = span.extensions_mut();

apollo-router/tests/integration/telemetry/jaeger.rs

@@ -342,7 +342,6 @@ async fn validate_trace(
         .finish();
 
     let id = id.to_string();
-    println!("trace id: {}", id);
     let url = format!("http://localhost:16686/api/traces/{id}?{params}");
     for _ in 0..10 {
         if find_valid_trace(
@@ -428,6 +427,12 @@ fn verify_router_span_fields(
             .first(),
         Some(&&Value::String("1.0".to_string()))
     );
+    assert!(router_span
+        .select_path("$.logs[*].fields[?(@.key == 'histogram.apollo_router_span')].value")?
+        .is_empty(),);
+    assert!(router_span
+        .select_path("$.logs[*].fields[?(@.key == 'histogram.apollo_router_span')].value")?
+        .is_empty(),);
     if custom_span_instrumentation {
         assert_eq!(
             router_span