Address review comments

Author: scottgerring

opentelemetry-sdk/CHANGELOG.md

@@ -10,9 +10,8 @@
     [#2338](https://github.com/open-telemetry/opentelemetry-rust/pull/2338)
   - `ResourceDetector.detect()` no longer supports timeout option.
   - `opentelemetry::global::shutdown_tracer_provider()` Removed from the API, should now use `tracer_provider.shutdown()` see [#2369](https://github.com/open-telemetry/opentelemetry-rust/pull/2369) for a migration example. "Tracer provider" is cheaply cloneable, so users are encouraged to set a clone of it as the global (ex: `global::set_tracer_provider(provider.clone()))`, so that instrumentations and other components can obtain tracers from `global::tracer()`. The tracer_provider must be kept around to call shutdown on it at the end of application (ex: `tracer_provider.shutdown()`)
-  - The trait functions `LogExporter.shutdown` and `TraceExporter.shutdown` now explicitly return a result. The
-    semantics of the method have not changed, but you will have a new lint encouraging you to consume these results.
-
+  - If you are an exporter author, the trait functions `LogExporter.shutdown` and `TraceExporter.shutdown` must now return a result. Note that implementing shutdown is optional as the trait provides a default implementation that returns Ok(()).
+  
 ## 0.27.1
 
 Released 2024-Nov-27

opentelemetry-sdk/src/export/trace.rs

@@ -7,12 +7,14 @@ use std::borrow::Cow;
 use std::fmt::Debug;
 use std::time::SystemTime;
 
-/// Describes the result of an export.
-pub type ExportResult = Result<(), TraceError>;
-
 /// Describes the results of other operations on the trace API.
 pub type TraceResult<T> = Result<T, TraceError>;
 
+/// Describes the results of an export
+/// Note: This is an alias we will remove in the future, favouring
+/// using TraceResult directly.
+pub type ExportResult = TraceResult<()>;
+
 /// `SpanExporter` defines the interface that protocol-specific exporters must
 /// implement so that they can be plugged into OpenTelemetry SDK and support
 /// sending of telemetry data.
@@ -33,7 +35,7 @@ pub trait SpanExporter: Send + Sync + Debug {
     ///
     /// Any retry logic that is required by the exporter is the responsibility
     /// of the exporter.
-    fn export(&mut self, batch: Vec<SpanData>) -> BoxFuture<'static, ExportResult>;
+    fn export(&mut self, batch: Vec<SpanData>) -> BoxFuture<'static, TraceResult<()>>;
 
     /// Shuts down the exporter. Called when SDK is shut down. This is an
     /// opportunity for exporter to do any cleanup required.

opentelemetry-sdk/src/logs/log_processor.rs

@@ -596,10 +596,6 @@ mod tests {
             Ok(())
         }
 
-        fn shutdown(&mut self) -> LogResult<()> {
-            Ok(())
-        }
-
         fn set_resource(&mut self, resource: &Resource) {
             self.resource
                 .lock()