Make sending traces to Tempo less confusing

Author: ndr-ds

CLI.md

@@ -150,7 +150,7 @@ Client implementation and command-line tool for the Linera blockchain
   Default value: `10`
 * `--chrome-trace-exporter` — Enable OpenTelemetry Chrome JSON exporter for trace data analysis
 * `--otel-trace-file <OTEL_TRACE_FILE>` — Output file path for Chrome trace JSON format. Can be visualized in chrome://tracing or Perfetto UI
-* `--otel-exporter-otlp-endpoint <OTEL_EXPORTER_OTLP_ENDPOINT>` — OpenTelemetry OTLP exporter endpoint (requires tempo feature)
+* `--otel-exporter-otlp-endpoint <OTEL_EXPORTER_OTLP_ENDPOINT>` — OpenTelemetry OTLP exporter endpoint (requires otel feature)
 * `--wait-for-outgoing-messages` — Whether to wait until a quorum of validators has confirmed that all sent cross-chain messages have been delivered
 * `--long-lived-services` — (EXPERIMENTAL) Whether application services can persist in some cases between queries
 * `--blanket-message-policy <BLANKET_MESSAGE_POLICY>` — The policy for handling incoming messages

docker/Dockerfile

@@ -25,7 +25,7 @@ ARG binaries=
 ARG copy=${binaries:+_copy}
 ARG build_flag=--release
 ARG build_folder=release
-ARG build_features=scylladb,metrics,memory-profiling,tempo
+ARG build_features=scylladb,metrics,memory-profiling,otel
 ARG rustflags="-C force-frame-pointers=yes"
 
 FROM rust:1.74-slim-bookworm AS builder

linera-base/Cargo.toml

@@ -18,7 +18,7 @@ workspace = true
 metrics = ["prometheus"]
 reqwest = ["dep:reqwest"]
 revm = []
-tempo = ["opentelemetry-otlp"]
+otel = ["opentelemetry-otlp"]
 test = ["test-strategy", "proptest"]
 web = [
     "getrandom/js",

linera-base/src/tracing_otel.rs

@@ -1,28 +1,26 @@
 // Copyright (c) Zefchain Labs, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-//! OpenTelemetry integration for tracing with OTLP export to Tempo and Chrome trace export.
+//! OpenTelemetry integration for tracing with OTLP export and Chrome trace export.
 
 use tracing_chrome::ChromeLayerBuilder;
 use tracing_subscriber::{layer::SubscriberExt as _, util::SubscriberInitExt as _};
-#[cfg(feature = "tempo")]
+#[cfg(feature = "otel")]
 use {
     opentelemetry::{global, trace::TracerProvider},
     opentelemetry_otlp::{SpanExporter, WithExportConfig},
     opentelemetry_sdk::{trace::SdkTracerProvider, Resource},
     tracing_opentelemetry::OpenTelemetryLayer,
-    tracing_subscriber::{
-        filter::{filter_fn, FilterExt as _},
-        layer::Layer,
-    },
+    tracing_subscriber::{filter::filter_fn, layer::Layer},
 };
 
-/// Initializes tracing with OpenTelemetry OTLP exporter to Tempo.
+/// Initializes tracing with OpenTelemetry OTLP exporter.
 ///
-/// Exports traces to Tempo using the OTLP protocol. Requires the `tempo` feature.
+/// Exports traces using the OTLP protocol to any OpenTelemetry-compatible backend.
+/// Requires the `otel` feature.
 /// Only enables OpenTelemetry if OTEL_EXPORTER_OTLP_ENDPOINT env var is set.
 /// This prevents DNS errors in environments where OpenTelemetry is not deployed.
-#[cfg(feature = "tempo")]
+#[cfg(feature = "otel")]
 pub fn init_with_opentelemetry(log_name: &str, otlp_endpoint: Option<&str>) {
     // Check if OpenTelemetry endpoint is configured via parameter or env var
     let endpoint = match otlp_endpoint {
@@ -59,15 +57,17 @@ pub fn init_with_opentelemetry(log_name: &str, otlp_endpoint: Option<&str>) {
     global::set_tracer_provider(tracer_provider.clone());
     let tracer = tracer_provider.tracer("linera");
 
-    let telemetry_only_filter =
-        filter_fn(|metadata| metadata.is_span() && metadata.target() == "telemetry_only");
+    let otel_filter = filter_fn(|metadata| {
+        if !metadata.is_span() {
+            return false;
+        }
+        metadata
+            .fields()
+            .field("otel.skip")
+            .is_none()
+    });
 
-    let otel_env_filter = tracing_subscriber::EnvFilter::builder()
-        .with_default_directive(tracing_subscriber::filter::LevelFilter::INFO.into())
-        .from_env_lossy();
-
-    let opentelemetry_filter = otel_env_filter.or(telemetry_only_filter);
-    let opentelemetry_layer = OpenTelemetryLayer::new(tracer).with_filter(opentelemetry_filter);
+    let opentelemetry_layer = OpenTelemetryLayer::new(tracer).with_filter(otel_filter);
 
     let config = crate::tracing::get_env_config(log_name);
     let maybe_log_file_layer = config.maybe_log_file_layer();
@@ -81,11 +81,11 @@ pub fn init_with_opentelemetry(log_name: &str, otlp_endpoint: Option<&str>) {
         .init();
 }
 
-/// Fallback when tempo feature is not enabled.
-#[cfg(not(feature = "tempo"))]
+/// Fallback when otel feature is not enabled.
+#[cfg(not(feature = "otel"))]
 pub fn init_with_opentelemetry(log_name: &str, _otlp_endpoint: Option<&str>) {
     eprintln!(
-        "OTLP export requires the 'tempo' feature to be enabled! Falling back to default tracing initialization."
+        "OTLP export requires the 'otel' feature to be enabled! Falling back to default tracing initialization."
     );
     crate::tracing::init(log_name);
 }

linera-chain/src/block_tracker.rs

@@ -101,7 +101,7 @@ impl<'resources, 'blobs> BlockExecutionTracker<'resources, 'blobs> {
     }
 
     /// Executes a transaction in the context of the block.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id,
         block_height = %self.block_height,
     ))]

linera-chain/src/chain.rs

@@ -390,7 +390,7 @@ where
         self.context().extra().chain_id()
     }
 
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
     ))]
     pub async fn query_application(
@@ -410,7 +410,7 @@ where
             .with_execution_context(ChainExecutionContext::Query)
     }
 
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
         application_id = %application_id
     ))]
@@ -425,7 +425,7 @@ where
             .with_execution_context(ChainExecutionContext::DescribeApplication)
     }
 
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
         target = %target,
         height = %height
@@ -556,7 +556,7 @@ where
     /// round timeouts.
     ///
     /// Returns `true` if incoming `Subscribe` messages created new outbox entries.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
         origin = %origin,
         bundle_height = %bundle.height
@@ -659,7 +659,7 @@ where
     /// If `must_be_present` is `true`, an error is returned if any of the bundles have not been
     /// added to the inbox yet. So this should be `true` if the bundles are in a block _proposal_,
     /// and `false` if the block is already confirmed.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
     ))]
     pub async fn remove_bundles_from_inboxes(
@@ -762,7 +762,7 @@ where
 
     /// Executes a block: first the incoming messages, then the main operation.
     /// Does not update chain state other than the execution state.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %block.chain_id,
         block_height = %block.height
     ))]
@@ -887,7 +887,7 @@ where
 
     /// Executes a block: first the incoming messages, then the main operation.
     /// Does not update chain state other than the execution state.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
         block_height = %block.height
     ))]
@@ -951,7 +951,7 @@ where
     /// Applies an execution outcome to the chain, updating the outboxes, state hash and chain
     /// manager. This does not touch the execution state itself, which must be updated separately.
     /// Returns the set of event streams that were updated as a result of applying the block.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
         block_height = %block.inner().inner().header.height
     ))]
@@ -989,7 +989,7 @@ where
 
     /// Adds a block to `preprocessed_blocks`, and updates the outboxes where possible.
     /// Returns the set of streams that were updated as a result of preprocessing the block.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
         block_height = %block.inner().inner().header.height
     ))]
@@ -1019,7 +1019,7 @@ where
     }
 
     /// Verifies that the block is valid according to the chain's application permission settings.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         block_height = %block.height,
         num_transactions = %block.transactions.len()
     ))]
@@ -1065,7 +1065,7 @@ where
     }
 
     /// Returns the hashes of all blocks we have in the given range.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
         next_block_height = %self.tip_state.get().next_block_height,
         start_height = ?range.start_bound(),
@@ -1123,7 +1123,7 @@ where
     /// Updates the outboxes with the messages sent in the block.
     ///
     /// Returns the set of all recipients.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
         block_height = %block.header.height
     ))]
@@ -1218,7 +1218,7 @@ where
     /// Updates the event streams with events emitted by the block if they form a contiguous
     /// sequence (might not be the case when preprocessing a block).
     /// Returns the set of updated event streams.
-    #[instrument(target = "telemetry_only", skip_all, fields(
+    #[instrument(skip_all, fields(
         chain_id = %self.chain_id(),
         block_height = %block.header.height
     ))]

linera-client/src/client_options.rs

@@ -112,7 +112,7 @@ pub struct ClientContextOptions {
     #[arg(long, env = "LINERA_OTEL_TRACE_FILE")]
     pub otel_trace_file: Option<String>,
 
-    /// OpenTelemetry OTLP exporter endpoint (requires tempo feature).
+    /// OpenTelemetry OTLP exporter endpoint (requires otel feature).
     #[arg(long, env = "LINERA_OTEL_EXPORTER_OTLP_ENDPOINT")]
     pub otel_exporter_otlp_endpoint: Option<String>,