fix: make shutdown_with_timeout required on LogProcessor (#3133)

Author: davidhewitt

examples/tracing-http-propagator/src/server.rs

@@ -121,6 +121,10 @@ impl LogProcessor for EnrichWithBaggageLogProcessor {
     fn force_flush(&self) -> OTelSdkResult {
         Ok(())
     }
+
+    fn shutdown_with_timeout(&self, _timeout: Duration) -> OTelSdkResult {
+        Ok(())
+    }
 }
 
 /// A custom span processor that enriches spans with baggage attributes. Baggage

opentelemetry-appender-tracing/benches/log-attributes.rs

@@ -43,6 +43,10 @@ impl LogProcessor for NoopProcessor {
     fn force_flush(&self) -> OTelSdkResult {
         Ok(())
     }
+
+    fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
+        Ok(())
+    }
 }
 
 /// Creates a single benchmark for a specific number of attributes

opentelemetry-appender-tracing/benches/logs.rs

@@ -62,6 +62,10 @@ impl LogProcessor for NoopProcessor {
     ) -> bool {
         self.enabled
     }
+
+    fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
+        Ok(())
+    }
 }
 
 struct NoOpLogLayer {

opentelemetry-appender-tracing/src/layer.rs

@@ -934,6 +934,10 @@ mod tests {
         fn force_flush(&self) -> OTelSdkResult {
             Ok(())
         }
+
+        fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
+            Ok(())
+        }
     }
 
     #[cfg(feature = "spec_unstable_logs_enabled")]

opentelemetry-proto/src/transform/logs.rs

@@ -241,6 +241,10 @@ mod tests {
         fn force_flush(&self) -> OTelSdkResult {
             Ok(())
         }
+
+        fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
+            Ok(())
+        }
     }
 
     fn create_test_log_data(

opentelemetry-sdk/CHANGELOG.md

@@ -21,6 +21,8 @@ Released 2025-Sep-25
   The logs functionality now operates independently, while automatic correlation
   between logs and traces continues to work when the "trace" feature is
   explicitly enabled.
+- **Fix**: Fix shutdown of `SimpleLogProcessor` and async `BatchLogProcessor`.
+- Default implementation of `LogProcessor::shutdown_with_timeout()` will now warn to encourage users to implement proper shutdown.
 
 ## 0.30.0
 
@@ -43,7 +45,7 @@ also modified to suppress telemetry before invoking exporters.
 
 - **Feature**: Implemented and enabled cardinality capping for Metrics by
   default. [#2901](https://github.com/open-telemetry/opentelemetry-rust/pull/2901)
-  - The default cardinality limit is 2000 and can be customized using Views.  
+  - The default cardinality limit is 2000 and can be customized using Views.
   - This feature was previously removed in version 0.28 due to the lack of
     configurability but has now been reintroduced with the ability to configure
     the limit.
@@ -184,7 +186,7 @@ Released 2025-Mar-21
   ```
 
   After:
-  
+
   ```rust
     async fn export(&self, batch: Vec<SpanData>) -> OTelSdkResult
   ```

opentelemetry-sdk/benches/log.rs

@@ -38,7 +38,7 @@ impl LogProcessor for NoopProcessor {
         Ok(())
     }
 
-    fn shutdown(&self) -> OTelSdkResult {
+    fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
         Ok(())
     }
 }

opentelemetry-sdk/benches/log_exporter.rs

@@ -73,7 +73,7 @@ impl LogProcessor for ExportingProcessorWithFuture {
         Ok(())
     }
 
-    fn shutdown(&self) -> OTelSdkResult {
+    fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
         Ok(())
     }
 }
@@ -104,7 +104,7 @@ impl LogProcessor for ExportingProcessorWithoutFuture {
         Ok(())
     }
 
-    fn shutdown(&self) -> OTelSdkResult {
+    fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
         Ok(())
     }
 }

opentelemetry-sdk/benches/log_processor.rs

@@ -54,7 +54,7 @@ impl LogProcessor for NoopProcessor {
         Ok(())
     }
 
-    fn shutdown(&self) -> OTelSdkResult {
+    fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
         Ok(())
     }
 }
@@ -71,7 +71,7 @@ impl LogProcessor for CloningProcessor {
         Ok(())
     }
 
-    fn shutdown(&self) -> OTelSdkResult {
+    fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
         Ok(())
     }
 }
@@ -117,7 +117,7 @@ impl LogProcessor for SendToChannelProcessor {
         Ok(())
     }
 
-    fn shutdown(&self) -> OTelSdkResult {
+    fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
         Ok(())
     }
 }

opentelemetry-sdk/src/logs/log_processor.rs

@@ -31,7 +31,7 @@ use crate::{logs::SdkLogRecord, Resource};
 
 #[cfg(feature = "spec_unstable_logs_enabled")]
 use opentelemetry::logs::Severity;
-use opentelemetry::InstrumentationScope;
+use opentelemetry::{otel_warn, InstrumentationScope};
 
 use std::fmt::Debug;
 use std::time::Duration;
@@ -57,10 +57,21 @@ pub trait LogProcessor: Send + Sync + Debug {
     /// Shuts down the processor.
     /// After shutdown returns the log processor should stop processing any logs.
     /// It's up to the implementation on when to drop the LogProcessor.
+    ///
+    /// All implementors should implement this method.
     fn shutdown_with_timeout(&self, _timeout: Duration) -> OTelSdkResult {
+        // It would have been better to make this method required, but that ship
+        // sailed when the logs API was declared stable.
+        otel_warn!(
+            name: "LogProcessor.DefaultShutdownWithTimeout",
+            message = format!("LogProcessor::shutdown_with_timeout should be implemented by all LogProcessor types")
+        );
         Ok(())
     }
     /// Shuts down the processor with default timeout.
+    ///
+    /// Implementors typically do not need to change this method, and can just
+    /// implement `shutdown_with_timeout`.
     fn shutdown(&self) -> OTelSdkResult {
         self.shutdown_with_timeout(Duration::from_secs(5))
     }
@@ -140,6 +151,10 @@ pub(crate) mod tests {
         fn force_flush(&self) -> OTelSdkResult {
             Ok(())
         }
+
+        fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
+            Ok(())
+        }
     }
 
     #[derive(Debug)]
@@ -166,6 +181,10 @@ pub(crate) mod tests {
         fn force_flush(&self) -> OTelSdkResult {
             Ok(())
         }
+
+        fn shutdown_with_timeout(&self, _timeout: std::time::Duration) -> OTelSdkResult {
+            Ok(())
+        }
     }
 
     #[test]