chore(tracing): Cleanup remanants of old tracing infrastructure

sfleen · sfleen · commit fb4e962397da · 2025-11-17T10:59:21.000-05:00
Signed-off-by: Scott Fleener &lt;scott@buoyant.io&gt;
diff --git a/linkerd/app/core/src/http_tracing.rs b/linkerd/app/core/src/http_tracing.rs
@@ -1,47 +1,15 @@
-use linkerd_error::Error;
+use linkerd_opentelemetry::otel::trace::SpanKind;
 use linkerd_stack::layer;
-use linkerd_trace_context::{
-    self as trace_context,
-    export::{ExportSpan, SpanKind, SpanLabels},
-    Span, TraceContext,
-};
-use std::sync::Arc;
-use tokio::sync::mpsc;
-
-pub type SpanSink = mpsc::Sender<ExportSpan>;
+use linkerd_trace_context::{export::SpanLabels, TraceContext};
 
 pub fn server<S>(
-    _sink: Option<SpanSink>,
     labels: impl Into<SpanLabels>,
 ) -> impl layer::Layer<S, Service = TraceContext<S>> + Clone {
     TraceContext::layer(SpanKind::Server, labels.into())
 }
 
 pub fn client<S>(
-    _sink: Option<SpanSink>,
     labels: impl Into<SpanLabels>,
 ) -> impl layer::Layer<S, Service = TraceContext<S>> + Clone {
     TraceContext::layer(SpanKind::Client, labels.into())
 }
-
-#[derive(Clone)]
-pub struct SpanConverter {
-    kind: SpanKind,
-    sink: SpanSink,
-    labels: SpanLabels,
-}
-
-impl trace_context::SpanSink for SpanConverter {
-    fn is_enabled(&self) -> bool {
-        true
-    }
-
-    fn try_send(&mut self, span: Span) -> Result<(), Error> {
-        self.sink.try_send(ExportSpan {
-            span,
-            kind: self.kind,
-            labels: Arc::clone(&self.labels),
-        })?;
-        Ok(())
-    }
-}
diff --git a/linkerd/app/core/src/lib.rs b/linkerd/app/core/src/lib.rs
@@ -65,7 +65,6 @@ pub struct ProxyRuntime {
     pub identity: identity::creds::Receiver,
     pub metrics: metrics::Proxy,
     pub tap: proxy::tap::Registry,
-    pub span_sink: Option<http_tracing::SpanSink>,
     pub drain: drain::Watch,
 }
 
diff --git a/linkerd/app/inbound/src/http/router.rs b/linkerd/app/inbound/src/http/router.rs
@@ -134,7 +134,7 @@ impl<C> Inbound<C> {
                             endpoint_labels(unsafe_authority_labels),
                         ),
                 )
-                .push_on_service(http_tracing::client(rt.span_sink.clone(), super::trace_labels()))
+                .push_on_service(http_tracing::client(super::trace_labels()))
                 .push_on_service(http::BoxResponse::layer())
                 .arc_new_http();
 
diff --git a/linkerd/app/inbound/src/http/server.rs b/linkerd/app/inbound/src/http/server.rs
@@ -78,10 +78,7 @@ impl<H> Inbound<H> {
                 .push_on_service(svc::MapErr::layer_boxed())
                 .push(rt.metrics.http_errors.to_layer())
                 .push(ServerRescue::layer())
-                .push_on_service(http_tracing::server(
-                    rt.span_sink.clone(),
-                    super::trace_labels(),
-                ))
+                .push_on_service(http_tracing::server(super::trace_labels()))
                 // Record when an HTTP/1 URI was in absolute form
                 .push_on_service(http::normalize_uri::MarkAbsoluteForm::layer())
                 .push_on_service(http::BoxResponse::layer())
diff --git a/linkerd/app/inbound/src/lib.rs b/linkerd/app/inbound/src/lib.rs
@@ -25,9 +25,7 @@ pub use self::{
 };
 use linkerd_app_core::{
     config::{ProxyConfig, QueueConfig},
-    drain,
-    http_tracing::SpanSink,
-    identity,
+    drain, identity,
     metrics::prom,
     proxy::tap,
     svc,
@@ -71,7 +69,6 @@ struct Runtime {
     metrics: InboundMetrics,
     identity: identity::creds::Receiver,
     tap: tap::Registry,
-    span_sink: Option<SpanSink>,
     drain: drain::Watch,
 }
 
@@ -154,7 +151,6 @@ impl Inbound<()> {
             metrics: InboundMetrics::new(runtime.metrics, prom),
             identity: runtime.identity,
             tap: runtime.tap,
-            span_sink: runtime.span_sink,
             drain: runtime.drain,
         };
         Self {
diff --git a/linkerd/app/inbound/src/test_util.rs b/linkerd/app/inbound/src/test_util.rs
@@ -99,7 +99,6 @@ pub fn runtime() -> (ProxyRuntime, drain::Signal) {
         identity: identity::creds::default_for_test().1,
         metrics: metrics.proxy,
         tap,
-        span_sink: None,
         drain,
     };
     (runtime, drain_tx)
diff --git a/linkerd/app/outbound/src/http/endpoint.rs b/linkerd/app/outbound/src/http/endpoint.rs
@@ -117,10 +117,7 @@ impl<T> Outbound<svc::ArcNewHttp<T, http::BoxBody>> {
                         .http_endpoint
                         .to_layer::<classify::Response, _, _>(),
                 )
-                .push_on_service(http_tracing::client(
-                    rt.span_sink.clone(),
-                    crate::trace_labels(),
-                ))
+                .push_on_service(http_tracing::client(crate::trace_labels()))
                 .push(NewRequireIdentity::layer())
                 .push(http::NewOverrideAuthority::layer(vec![
                     "host",
diff --git a/linkerd/app/outbound/src/http/server.rs b/linkerd/app/outbound/src/http/server.rs
@@ -48,7 +48,7 @@ impl<T> Outbound<svc::ArcNewCloneHttp<T>> {
                 .push(ServerRescue::layer(config.emit_headers))
                 .check_new_service::<T, http::Request<_>>()
                 // Initiates OpenTelemetry tracing.
-                .push_on_service(http_tracing::server(rt.span_sink.clone(), trace_labels()))
+                .push_on_service(http_tracing::server(trace_labels()))
                 .push_on_service(http::BoxResponse::layer())
                 // Convert origin form HTTP/1 URIs to absolute form for Hyper's
                 // `Client`.
diff --git a/linkerd/app/outbound/src/lib.rs b/linkerd/app/outbound/src/lib.rs
@@ -10,7 +10,6 @@ use linkerd_app_core::{
     config::{ProxyConfig, QueueConfig},
     drain,
     exp_backoff::ExponentialBackoff,
-    http_tracing::SpanSink,
     identity, io,
     metrics::prom,
     profiles,
@@ -97,7 +96,6 @@ struct Runtime {
     metrics: OutboundMetrics,
     identity: identity::NewClient,
     tap: tap::Registry,
-    span_sink: Option<SpanSink>,
     drain: drain::Watch,
 }
 
@@ -127,7 +125,6 @@ impl Outbound<()> {
             metrics: OutboundMetrics::new(runtime.metrics, prom),
             identity: runtime.identity.new_client(),
             tap: runtime.tap,
-            span_sink: runtime.span_sink,
             drain: runtime.drain,
         };
         Self {
diff --git a/linkerd/app/outbound/src/test_util.rs b/linkerd/app/outbound/src/test_util.rs
@@ -63,7 +63,6 @@ pub(crate) fn runtime() -> (ProxyRuntime, drain::Signal) {
         identity: linkerd_meshtls::creds::default_for_test().1,
         metrics: metrics.proxy,
         tap,
-        span_sink: None,
         drain,
     };
     (runtime, drain_tx)
diff --git a/linkerd/app/src/lib.rs b/linkerd/app/src/lib.rs
@@ -215,7 +215,6 @@ impl Config {
             identity: identity.receiver(),
             metrics: metrics.proxy,
             tap: tap.registry(),
-            span_sink: trace_collector.span_sink(),
             drain: drain_rx.clone(),
         };
         let inbound = Inbound::new(
diff --git a/linkerd/app/src/trace_collector.rs b/linkerd/app/src/trace_collector.rs
@@ -1,15 +1,12 @@
 use linkerd_app_core::{
-    control, dns, http_tracing::SpanSink, identity, metrics::ControlHttp as HttpMetrics,
-    opentelemetry, svc::NewService,
+    control, dns, identity, metrics::ControlHttp as HttpMetrics, opentelemetry, svc::NewService,
 };
 use linkerd_error::Error;
 use otel_collector::OtelCollectorAttributes;
 use std::{collections::HashMap, future::Future, pin::Pin};
 
 pub mod otel_collector;
 
-const SPAN_BUFFER_CAPACITY: usize = 100;
-
 #[derive(Clone, Debug)]
 pub enum Config {
     Disabled,
@@ -32,16 +29,6 @@ pub enum TraceCollector {
 
 pub struct EnabledCollector {
     pub addr: control::ControlAddr,
-    pub span_sink: SpanSink,
-}
-
-impl TraceCollector {
-    pub fn span_sink(&self) -> Option<SpanSink> {
-        match self {
-            TraceCollector::Disabled => None,
-            TraceCollector::Enabled(inner) => Some(inner.span_sink.clone()),
-        }
-    }
 }
 
 impl Config {
diff --git a/linkerd/app/src/trace_collector/otel_collector.rs b/linkerd/app/src/trace_collector/otel_collector.rs
@@ -5,7 +5,6 @@ use std::{
     collections::HashMap,
     time::{SystemTime, UNIX_EPOCH},
 };
-use tokio::sync::mpsc;
 use tonic::{body::Body as TonicBody, client::GrpcService};
 
 pub(super) struct OtelCollectorAttributes {
@@ -26,8 +25,6 @@ where
     S::ResponseBody: Body<Data = tonic::codegen::Bytes> + Send + 'static,
     <S::ResponseBody as Body>::Error: Into<Error> + Send,
 {
-    let (span_sink, _) = mpsc::channel(crate::trace_collector::SPAN_BUFFER_CAPACITY);
-
     let resource = sdk::Resource::builder()
         .with_attribute(KeyValue::new(
             semconv::attribute::PROCESS_PID,
@@ -55,5 +52,5 @@ where
     let addr = addr.clone();
     opentelemetry::install_opentelemetry_providers(svc, resource, legacy_metrics);
 
-    EnabledCollector { addr, span_sink }
+    EnabledCollector { addr }
 }
diff --git a/linkerd/trace-context/src/export.rs b/linkerd/trace-context/src/export.rs
@@ -1,27 +1,4 @@
-use crate::Span;
 use std::collections::HashMap;
 use std::sync::Arc;
 
-#[derive(Copy, Clone, Debug, PartialEq)]
-pub enum SpanKind {
-    Server = 1,
-    Client = 2,
-}
-
-impl From<SpanKind> for opentelemetry::trace::SpanKind {
-    fn from(value: SpanKind) -> Self {
-        match value {
-            SpanKind::Server => opentelemetry::trace::SpanKind::Server,
-            SpanKind::Client => opentelemetry::trace::SpanKind::Client,
-        }
-    }
-}
-
 pub type SpanLabels = Arc<HashMap<String, String>>;
-
-#[derive(Debug)]
-pub struct ExportSpan {
-    pub span: Span,
-    pub kind: SpanKind,
-    pub labels: SpanLabels,
-}
diff --git a/linkerd/trace-context/src/lib.rs b/linkerd/trace-context/src/lib.rs
@@ -6,7 +6,6 @@ mod service;
 
 pub use self::service::TraceContext;
 use bytes::Bytes;
-use linkerd_error::Error;
 use opentelemetry::{KeyValue, SpanId, TraceId};
 use std::fmt;
 use std::time::SystemTime;
@@ -54,24 +53,6 @@ pub struct Span {
     pub labels: Vec<KeyValue>,
 }
 
-pub trait SpanSink {
-    fn is_enabled(&self) -> bool;
-
-    fn try_send(&mut self, span: Span) -> Result<(), Error>;
-}
-
-impl<K: SpanSink> SpanSink for Option<K> {
-    #[inline]
-    fn is_enabled(&self) -> bool {
-        self.as_ref().map(SpanSink::is_enabled).unwrap_or(false)
-    }
-
-    #[inline]
-    fn try_send(&mut self, span: Span) -> Result<(), Error> {
-        self.as_mut().expect("Must be enabled").try_send(span)
-    }
-}
-
 // === impl Id ===
 
 impl From<Id> for Vec<u8> {
diff --git a/linkerd/trace-context/src/service.rs b/linkerd/trace-context/src/service.rs
@@ -1,9 +1,9 @@
-use crate::export::{SpanKind, SpanLabels};
+use crate::export::SpanLabels;
 use futures::{future::Either, prelude::*};
 use http::Uri;
 use linkerd_stack::layer;
 use opentelemetry::context::FutureExt;
-use opentelemetry::trace::{Span, SpanRef, TraceContextExt, Tracer};
+use opentelemetry::trace::{Span, SpanKind, SpanRef, TraceContextExt, Tracer};
 use opentelemetry::KeyValue;
 use opentelemetry_http::{HeaderExtractor, HeaderInjector};
 use opentelemetry_semantic_conventions as semconv;
@@ -39,7 +39,7 @@ impl<S> TraceContext<S> {
     ) -> impl layer::Layer<S, Service = TraceContext<S>> + Clone {
         layer::mk(move |inner| TraceContext {
             inner,
-            kind,
+            kind: kind.clone(),
             labels: labels.clone(),
         })
     }
@@ -225,7 +225,7 @@ where
             let span_name = req.uri().path().to_owned();
             let mut span = tracer
                 .span_builder(span_name)
-                .with_kind(self.kind.into())
+                .with_kind(self.kind.clone())
                 .start_with_context(&tracer, &parent_ctx);
             self.add_request_labels(&mut span, &req);
 

Original file line number	Diff line number	Diff line change
`@@ -65,7 +65,6 @@ pub struct ProxyRuntime {`
`65`	`65`	`pub identity: identity::creds::Receiver,`
`66`	`66`	`pub metrics: metrics::Proxy,`
`67`	`67`	`pub tap: proxy::tap::Registry,`
`68`		`- pub span_sink: Option<http_tracing::SpanSink>,`
`69`	`68`	`pub drain: drain::Watch,`
`70`	`69`	`}`
`71`	`70`
Original file line number	Diff line number	Diff line change
`@@ -134,7 +134,7 @@ impl<C> Inbound<C> {`
`134`	`134`	`endpoint_labels(unsafe_authority_labels),`
`135`	`135`	`),`
`136`	`136`	`)`
`137`		`- .push_on_service(http_tracing::client(rt.span_sink.clone(), super::trace_labels()))`
	`137`	`+ .push_on_service(http_tracing::client(super::trace_labels()))`
`138`	`138`	`.push_on_service(http::BoxResponse::layer())`
`139`	`139`	`.arc_new_http();`
`140`	`140`