Fix OTel Appender for tracing from suppressing other layers (open-telemetry#2668)

Author: cijothomas

opentelemetry-appender-tracing/CHANGELOG.md

@@ -2,13 +2,14 @@
 
 ## vNext
 
+Fixes [1682](https://github.com/open-telemetry/opentelemetry-rust/issues/1682).
+"spec_unstable_logs_enabled" feature now do not suppress logs for other layers.
+
 ## 0.28.1
 
 Released 2025-Feb-12
 
-- Bump `tracing-opentelemetry` to 0.29
-- New experimental feature to use trace\_id & span\_id from spans created through the [tracing](https://crates.io/crates/tracing) crate (experimental_use_tracing_span_context) [#2438](https://github.com/open-telemetry/opentelemetry-rust/pull/2438)
-
+- New *experimental* feature to use trace_id & span_id from spans created through the [tracing](https://crates.io/crates/tracing) crate (experimental_use_tracing_span_context) [#2438](https://github.com/open-telemetry/opentelemetry-rust/pull/2438)
 
 ## 0.28.0
 
@@ -27,6 +28,7 @@ Released 2024-Nov-11
 - **Breaking** [2291](https://github.com/open-telemetry/opentelemetry-rust/pull/2291) Rename `logs_level_enabled flag` to `spec_unstable_logs_enabled`. Please enable this updated flag if the feature is needed. This flag will be removed once the feature is stabilized in the specifications.
 
 ## v0.26.0
+
 Released 2024-Sep-30
 
 - Update `opentelemetry` dependency version to 0.26
@@ -45,7 +47,7 @@ Released 2024-Sep-30
   Exporters might use the target to override the instrumentation scope, which previously contained "opentelemetry-appender-tracing".
 
 - **Breaking** [1928](https://github.com/open-telemetry/opentelemetry-rust/pull/1928) Insert tracing event name into LogRecord::event_name instead of attributes.
-   - If using a custom exporter, then they must serialize this field directly from LogRecord::event_name instead of iterating over the attributes. OTLP Exporter is modified to handle this.
+  - If using a custom exporter, then they must serialize this field directly from LogRecord::event_name instead of iterating over the attributes. OTLP Exporter is modified to handle this.
 - Update `opentelemetry` dependency version to 0.24
 
 ## v0.4.0

opentelemetry-appender-tracing/Cargo.toml

@@ -36,7 +36,6 @@ pprof = { version = "0.14", features = ["flamegraph", "criterion"] }
 default = []
 experimental_metadata_attributes = ["dep:tracing-log"]
 spec_unstable_logs_enabled = ["opentelemetry/spec_unstable_logs_enabled"]
-# TODO - Enable this in 0.28.1 (once tracing-opentelemetry v0.29 is released)
 experimental_use_tracing_span_context = ["tracing-opentelemetry"]
 
 

opentelemetry-appender-tracing/benches/logs.rs

@@ -17,7 +17,6 @@ use criterion::{criterion_group, criterion_main, Criterion};
 use opentelemetry::InstrumentationScope;
 use opentelemetry_appender_tracing::layer as tracing_layer;
 use opentelemetry_sdk::error::OTelSdkResult;
-use opentelemetry_sdk::logs::{LogBatch, LogExporter};
 use opentelemetry_sdk::logs::{LogProcessor, SdkLogRecord, SdkLoggerProvider};
 use opentelemetry_sdk::Resource;
 #[cfg(not(target_os = "windows"))]
@@ -27,40 +26,19 @@ use tracing_subscriber::prelude::*;
 use tracing_subscriber::Layer;
 use tracing_subscriber::Registry;
 
-#[derive(Debug, Clone)]
-struct NoopExporter {
-    enabled: bool,
-}
-
-impl LogExporter for NoopExporter {
-    #[allow(clippy::manual_async_fn)]
-    fn export(
-        &self,
-        _batch: LogBatch<'_>,
-    ) -> impl std::future::Future<Output = OTelSdkResult> + Send {
-        async { OTelSdkResult::Ok(()) }
-    }
-
-    fn event_enabled(&self, _: opentelemetry::logs::Severity, _: &str, _: &str) -> bool {
-        self.enabled
-    }
-}
-
 #[derive(Debug)]
-struct NoopProcessor<E: LogExporter> {
-    exporter: E,
+struct NoopProcessor {
+    enabled: bool,
 }
 
-impl<E: LogExporter> NoopProcessor<E> {
-    fn new(exporter: E) -> Self {
-        Self { exporter }
+impl NoopProcessor {
+    fn new(enabled: bool) -> Self {
+        Self { enabled }
     }
 }
 
-impl<E: LogExporter> LogProcessor for NoopProcessor<E> {
-    fn emit(&self, _: &mut SdkLogRecord, _: &InstrumentationScope) {
-        // no-op
-    }
+impl LogProcessor for NoopProcessor {
+    fn emit(&self, _: &mut SdkLogRecord, _: &InstrumentationScope) {}
 
     fn force_flush(&self) -> OTelSdkResult {
         Ok(())
@@ -72,11 +50,11 @@ impl<E: LogExporter> LogProcessor for NoopProcessor<E> {
 
     fn event_enabled(
         &self,
-        level: opentelemetry::logs::Severity,
-        target: &str,
-        name: &str,
+        _level: opentelemetry::logs::Severity,
+        _target: &str,
+        _name: &str,
     ) -> bool {
-        self.exporter.event_enabled(level, target, name)
+        self.enabled
     }
 }
 
@@ -126,8 +104,7 @@ fn benchmark_no_subscriber(c: &mut Criterion) {
 }
 
 fn benchmark_with_ot_layer(c: &mut Criterion, enabled: bool, bench_name: &str) {
-    let exporter = NoopExporter { enabled };
-    let processor = NoopProcessor::new(exporter);
+    let processor = NoopProcessor::new(enabled);
     let provider = SdkLoggerProvider::builder()
         .with_resource(
             Resource::builder_empty()

opentelemetry-appender-tracing/src/layer.rs

@@ -158,6 +158,14 @@ where
         event: &tracing::Event<'_>,
         _ctx: tracing_subscriber::layer::Context<'_, S>,
     ) {
+        let severity = severity_of_level(event.metadata().level());
+        let target = event.metadata().target();
+        #[cfg(feature = "spec_unstable_logs_enabled")]
+        if !self.logger.event_enabled(severity, target) {
+            // TODO: See if we need internal logs or track the count.
+            return;
+        }
+
         #[cfg(feature = "experimental_metadata_attributes")]
         let normalized_meta = event.normalized_metadata();
 
@@ -170,9 +178,9 @@ where
         let mut log_record = self.logger.create_log_record();
 
         // TODO: Fix heap allocation
-        log_record.set_target(meta.target().to_string());
+        log_record.set_target(target.to_string());
         log_record.set_event_name(meta.name());
-        log_record.set_severity_number(severity_of_level(meta.level()));
+        log_record.set_severity_number(severity);
         log_record.set_severity_text(meta.level().as_str());
         let mut visitor = EventVisitor::new(&mut log_record);
         #[cfg(feature = "experimental_metadata_attributes")]
@@ -203,17 +211,6 @@ where
         //emit record
         self.logger.emit(log_record);
     }
-
-    #[cfg(feature = "spec_unstable_logs_enabled")]
-    fn event_enabled(
-        &self,
-        _event: &tracing_core::Event<'_>,
-        _ctx: tracing_subscriber::layer::Context<'_, S>,
-    ) -> bool {
-        let severity = severity_of_level(_event.metadata().level());
-        self.logger
-            .event_enabled(severity, _event.metadata().target())
-    }
 }
 
 const fn severity_of_level(level: &Level) -> Severity {