fix: Remove mut ref requirement for shutdown LogExporter

opentelemetry-otlp/CHANGELOG.md

@@ -4,6 +4,10 @@
 
 - The `OTEL_EXPORTER_OTLP_TIMEOUT`, `OTEL_EXPORTER_OTLP_TRACES_TIMEOUT`, `OTEL_EXPORTER_OTLP_METRICS_TIMEOUT` and `OTEL_EXPORTER_OTLP_LOGS_TIMEOUT` are changed from seconds to miliseconds.
 - Fixed `.with_headers()` in `HttpExporterBuilder` to correctly support multiple key/value pairs. [#2699](https://github.com/open-telemetry/opentelemetry-rust/pull/2699)
+- Fixed
+  [#2770](https://github.com/open-telemetry/opentelemetry-rust/issues/2770)
+  partially to properly handle `shutdown()` when using `http`. (`tonic` still
+  does not do proper shutdown)
 
 ## 0.28.0
 

opentelemetry-otlp/src/exporter/http/logs.rs

@@ -46,7 +46,7 @@
         Ok(())
     }
 
-    fn shutdown(&mut self) -> OTelSdkResult {
+    fn shutdown(&self) -> OTelSdkResult {
         let mut client_guard = self.client.lock().map_err(|e| {
             OTelSdkError::InternalFailure(format!("Failed to acquire client lock: {}", e))
         })?;

opentelemetry-otlp/src/exporter/tonic/logs.rs

@@ -5,23 +5,23 @@
 };
 use opentelemetry_sdk::error::{OTelSdkError, OTelSdkResult};
 use opentelemetry_sdk::logs::{LogBatch, LogExporter};
+use tokio::sync::Mutex;
 use tonic::{codegen::CompressionEncoding, service::Interceptor, transport::Channel, Request};
 
 use opentelemetry_proto::transform::logs::tonic::group_logs_by_resource_and_scope;
 
 use super::BoxInterceptor;
-use tokio::sync::Mutex;
 
 pub(crate) struct TonicLogsClient {
-    inner: Option<ClientInner>,
+    inner: Mutex<Option<ClientInner>>,
     #[allow(dead_code)]
     // <allow dead> would be removed once we support set_resource for metrics.
     resource: opentelemetry_proto::transform::common::tonic::ResourceAttributesWithSchema,
 }
 
 struct ClientInner {
     client: LogsServiceClient<Channel>,
-    interceptor: Mutex<BoxInterceptor>,
+    interceptor: BoxInterceptor,
 }
 
 impl fmt::Debug for TonicLogsClient {
@@ -46,23 +46,21 @@
         otel_debug!(name: "TonicsLogsClientBuilt");
 
         TonicLogsClient {
-            inner: Some(ClientInner {
+            inner: Mutex::new(Some(ClientInner {
                 client,
-                interceptor: Mutex::new(interceptor),
-            }),
+                interceptor,
+            })),
             resource: Default::default(),
         }
     }
 }
 
 impl LogExporter for TonicLogsClient {
     async fn export(&self, batch: LogBatch<'_>) -> OTelSdkResult {
-        let (mut client, metadata, extensions) = match &self.inner {
+        let (mut client, metadata, extensions) = match self.inner.lock().await.as_mut() {
             Some(inner) => {
                 let (m, e, _) = inner
                     .interceptor
-                    .lock()
-                    .await // tokio::sync::Mutex doesn't return a poisoned error, so we can safely use the interceptor here
                     .call(Request::new(()))
                     .map_err(|e| OTelSdkError::InternalFailure(format!("error: {:?}", e)))?
                     .into_parts();
@@ -86,11 +84,15 @@
         Ok(())
     }
 
-    fn shutdown(&mut self) -> OTelSdkResult {
-        match self.inner.take() {
-            Some(_) => Ok(()), // Successfully took `inner`, indicating a successful shutdown.
-            None => Err(OTelSdkError::AlreadyShutdown), // `inner` was already `None`, meaning it's already shut down.
-        }
+    fn shutdown(&self) -> OTelSdkResult {
+        // TODO: Implement actual shutdown
+        // Due to the use of tokio::sync::Mutex to guard
+        // the inner client, we need to await the call to lock the mutex
+        // and that requires async runtime.
+        // It is possible to fix this by using
+        // a dedicated thread just to handle shutdown.
+        // But for now, we just return Ok.
+        Ok(())
     }
 
     fn set_resource(&mut self, resource: &opentelemetry_sdk::Resource) {

opentelemetry-otlp/src/logs.rs

@@ -156,4 +156,13 @@
             SupportedTransportClient::Http(client) => client.set_resource(resource),
         }
     }
+
+    fn shutdown(&self) -> OTelSdkResult {
+        match &self.client {
+            #[cfg(feature = "grpc-tonic")]
+            SupportedTransportClient::Tonic(client) => client.shutdown(),
+            #[cfg(any(feature = "http-proto", feature = "http-json"))]
+            SupportedTransportClient::Http(client) => client.shutdown(),
+        }
+    }
 }

opentelemetry-sdk/CHANGELOG.md

@@ -60,6 +60,10 @@
   `LogProcessor` and `LogExporter` traits. `SdkLogger` no longer passes its
   `scope` name but instead passes the incoming `name` when invoking
   `event_enabled` on processors.
+- **Breaking** for custom LogExporter authors: `shutdown()` method in
+ `LogExporter` trait no longer requires a mutable ref to `self`. If the exporter
+ needs to mutate state, it should rely on interior mutability.
+ [2764](https://github.com/open-telemetry/opentelemetry-rust/pull/2764)
 
 ## 0.28.0
 

opentelemetry-sdk/src/logs/export.rs

@@ -136,7 +136,7 @@
     ) -> impl std::future::Future<Output = OTelSdkResult> + Send;
 
     /// Shuts down the exporter.
-    fn shutdown(&mut self) -> OTelSdkResult {
+    fn shutdown(&self) -> OTelSdkResult {
         Ok(())
     }
     #[cfg(feature = "spec_unstable_logs_enabled")]

opentelemetry-sdk/src/logs/in_memory_exporter.rs

@@ -211,7 +211,7 @@ impl LogExporter for InMemoryLogExporter {
         Ok(())
     }
 
-    fn shutdown(&mut self) -> OTelSdkResult {
+    fn shutdown(&self) -> OTelSdkResult {
         self.shutdown_called
             .store(true, std::sync::atomic::Ordering::Relaxed);
         if self.should_reset_on_shutdown {

opentelemetry-sdk/src/logs/log_processor.rs

@@ -92,7 +92,7 @@ pub(crate) mod tests {
             Ok(())
         }
 
-        fn shutdown(&mut self) -> OTelSdkResult {
+        fn shutdown(&self) -> OTelSdkResult {
             Ok(())
         }
 

opentelemetry-sdk/src/logs/log_processor_with_async_runtime.rs

@@ -321,7 +321,7 @@ mod tests {
             Ok(())
         }
 
-        fn shutdown(&mut self) -> OTelSdkResult {
+        fn shutdown(&self) -> OTelSdkResult {
             Ok(())
         }
 

opentelemetry-sdk/src/logs/simple_log_processor.rs

@@ -117,7 +117,7 @@ impl<T: LogExporter> LogProcessor for SimpleLogProcessor<T> {
     fn shutdown(&self) -> OTelSdkResult {
         self.is_shutdown
             .store(true, std::sync::atomic::Ordering::Relaxed);
-        if let Ok(mut exporter) = self.exporter.lock() {
+        if let Ok(exporter) = self.exporter.lock() {
             exporter.shutdown()
         } else {
             Err(OTelSdkError::InternalFailure(

opentelemetry-stdout/src/logs/exporter.rs

@@ -57,7 +57,7 @@
         }
     }
 
-    fn shutdown(&mut self) -> OTelSdkResult {
+    fn shutdown(&self) -> OTelSdkResult {
         self.is_shutdown.store(true, atomic::Ordering::SeqCst);
         Ok(())
     }