chore: modify tonic exporters so we don't _need_ the async runtime if we don't want retry

Author: scottgerring

opentelemetry-otlp/Cargo.toml

@@ -70,10 +70,13 @@ serialize = ["serde", "serde_json"]
 default = ["http-proto", "reqwest-blocking-client", "trace", "metrics", "logs", "internal-logs"]
 
 # grpc using tonic
-grpc-tonic = ["tonic", "tonic-types", "prost", "http", "tokio", "opentelemetry-proto/gen-tonic", "opentelemetry_sdk/rt-tokio", "opentelemetry_sdk/experimental_async_runtime"]
+grpc-tonic = ["tonic", "tonic-types", "prost", "http", "tokio", "opentelemetry-proto/gen-tonic"]
 gzip-tonic = ["tonic/gzip"]
 zstd-tonic = ["tonic/zstd"]
 
+# grpc with retry support
+grpc-retry = ["grpc-tonic", "opentelemetry_sdk/experimental_async_runtime"]
+
 # http compression
 gzip-http = ["flate2"]
 zstd-http = ["zstd"]

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

@@ -14,8 +14,7 @@ use opentelemetry_proto::transform::logs::tonic::group_logs_by_resource_and_scop
 
 use super::BoxInterceptor;
 
-use crate::retry_classification::grpc::classify_tonic_status;
-use opentelemetry_sdk::retry::{retry_with_backoff, RetryPolicy};
+use opentelemetry_sdk::retry::RetryPolicy;
 use opentelemetry_sdk::runtime::Tokio;
 
 pub(crate) struct TonicLogsClient {
@@ -73,10 +72,10 @@ impl LogExporter for TonicLogsClient {
     async fn export(&self, batch: LogBatch<'_>) -> OTelSdkResult {
         let batch = Arc::new(batch);
 
-        match retry_with_backoff(
+        match super::tonic_retry_with_backoff(
             Tokio,
             self.retry_policy.clone(),
-            classify_tonic_status,
+            crate::retry_classification::grpc::classify_tonic_status,
             "TonicLogsClient.Export",
             || async {
                 let batch_clone = Arc::clone(&batch);

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

@@ -12,8 +12,7 @@ use tonic::{codegen::CompressionEncoding, service::Interceptor, transport::Chann
 use super::BoxInterceptor;
 use crate::metric::MetricsClient;
 
-use crate::retry_classification::grpc::classify_tonic_status;
-use opentelemetry_sdk::retry::{retry_with_backoff, RetryPolicy};
+use opentelemetry_sdk::retry::RetryPolicy;
 use opentelemetry_sdk::runtime::Tokio;
 
 pub(crate) struct TonicMetricsClient {
@@ -65,10 +64,10 @@ impl TonicMetricsClient {
 
 impl MetricsClient for TonicMetricsClient {
     async fn export(&self, metrics: &ResourceMetrics) -> OTelSdkResult {
-        match retry_with_backoff(
+        match super::tonic_retry_with_backoff(
             Tokio,
             self.retry_policy.clone(),
-            classify_tonic_status,
+            crate::retry_classification::grpc::classify_tonic_status,
             "TonicMetricsClient.Export",
             || async {
                 // Execute the export operation

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

@@ -18,6 +18,12 @@ use crate::{ExportConfig, OTEL_EXPORTER_OTLP_ENDPOINT, OTEL_EXPORTER_OTLP_HEADER
 
 #[cfg(feature = "grpc-tonic")]
 use opentelemetry_sdk::retry::RetryPolicy;
+#[cfg(feature = "grpc-retry")]
+use opentelemetry_sdk::retry::retry_with_backoff;
+#[cfg(feature = "grpc-tonic")]
+use opentelemetry_sdk::runtime::Runtime;
+#[cfg(feature = "grpc-tonic")]
+use std::future::Future;
 
 #[cfg(feature = "logs")]
 pub(crate) mod logs;
@@ -44,7 +50,7 @@ pub struct TonicConfig {
     pub(crate) channel: Option<tonic::transport::Channel>,
     pub(crate) interceptor: Option<BoxInterceptor>,
     /// The retry policy to use for gRPC requests.
-    #[cfg(feature = "grpc-tonic")]
+    #[cfg(feature = "grpc-retry")]
     pub(crate) retry_policy: Option<RetryPolicy>,
 }
 
@@ -138,7 +144,7 @@ impl Default for TonicExporterBuilder {
                 compression: None,
                 channel: Option::default(),
                 interceptor: Option::default(),
-                #[cfg(feature = "grpc-tonic")]
+                #[cfg(feature = "grpc-retry")]
                 retry_policy: None,
             },
             exporter_config: ExportConfig {
@@ -190,14 +196,14 @@ impl TonicExporterBuilder {
         };
 
         // Get retry policy before consuming self
-        #[cfg(feature = "grpc-tonic")]
+        #[cfg(feature = "grpc-retry")]
         let retry_policy = self.tonic_config.retry_policy.clone();
 
         // If a custom channel was provided, use that channel instead of creating one
         if let Some(channel) = self.tonic_config.channel {
             return Ok((channel, interceptor, compression, 
-                #[cfg(feature = "grpc-tonic")] retry_policy,
-                #[cfg(not(feature = "grpc-tonic"))] None));
+                #[cfg(feature = "grpc-retry")] retry_policy,
+                #[cfg(not(feature = "grpc-retry"))] None));
         }
 
         let config = self.exporter_config;
@@ -226,8 +232,8 @@ impl TonicExporterBuilder {
 
         otel_debug!(name: "TonicChannelBuilt", endpoint = endpoint_clone, timeout_in_millisecs = timeout.as_millis(), compression = format!("{:?}", compression), headers = format!("{:?}", headers_for_logging));
         Ok((channel, interceptor, compression, 
-            #[cfg(feature = "grpc-tonic")] retry_policy,
-            #[cfg(not(feature = "grpc-tonic"))] None))
+            #[cfg(feature = "grpc-retry")] retry_policy,
+            #[cfg(not(feature = "grpc-retry"))] None))
     }
 
     fn resolve_endpoint(default_endpoint_var: &str, provided_endpoint: Option<String>) -> String {
@@ -320,6 +326,40 @@ impl TonicExporterBuilder {
     }
 }
 
+/// Wrapper for retry functionality in tonic exporters.
+/// Provides a unified call path that either uses retry_with_backoff when grpc-retry
+/// feature is enabled, or executes the operation once when it's not.
+#[cfg(feature = "grpc-tonic")]
+async fn tonic_retry_with_backoff<R, F, Fut, T>(
+    runtime: R,
+    policy: RetryPolicy,
+    classify_fn: fn(&tonic::Status) -> opentelemetry_sdk::retry::RetryErrorType,
+    operation_name: &'static str,
+    operation: F,
+) -> Result<T, tonic::Status>
+where
+    R: Runtime,
+    F: Fn() -> Fut,
+    Fut: Future<Output = Result<T, tonic::Status>>,
+{
+    #[cfg(feature = "grpc-retry")]
+    {
+        retry_with_backoff(runtime, policy, classify_fn, operation_name, operation).await
+    }
+    
+    #[cfg(not(feature = "grpc-retry"))]
+    {
+        // When retry feature is not enabled, execute operation once
+        // avoid unused param warnings ...
+        let _ = runtime;
+        let _ = policy;
+        let _ = classify_fn;
+        let _ = operation_name;
+        
+        operation().await
+    }
+}
+
 fn merge_metadata_with_headers_from_env(
     metadata: MetadataMap,
     headers_from_env: HeaderMap,
@@ -493,7 +533,7 @@ pub trait WithTonicConfig {
         I: tonic::service::Interceptor + Clone + Send + Sync + 'static;
 
     /// Set the retry policy for gRPC requests.
-    #[cfg(feature = "grpc-tonic")]
+    #[cfg(feature = "grpc-retry")]
     fn with_retry_policy(self, policy: RetryPolicy) -> Self;
 }
 
@@ -537,7 +577,7 @@ impl<B: HasTonicConfig> WithTonicConfig for B {
         self
     }
 
-    #[cfg(feature = "grpc-tonic")]
+    #[cfg(feature = "grpc-retry")]
     fn with_retry_policy(mut self, policy: RetryPolicy) -> Self {
         self.tonic_config().retry_policy = Some(policy);
         self
@@ -775,7 +815,7 @@ mod tests {
         });
     }
 
-    #[cfg(feature = "grpc-tonic")]
+    #[cfg(feature = "grpc-retry")]
     #[test]
     fn test_with_retry_policy() {
         use crate::WithTonicConfig;
@@ -798,7 +838,7 @@ mod tests {
         assert_eq!(retry_policy.jitter_ms, 50);
     }
 
-    #[cfg(feature = "grpc-tonic")]
+    #[cfg(feature = "grpc-retry")]
     #[test]
     fn test_default_retry_policy_when_none_configured() {
         // This test requires us to create a tonic client, but we can't easily do that without

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

@@ -16,8 +16,7 @@ use tonic::{codegen::CompressionEncoding, service::Interceptor, transport::Chann
 
 use super::BoxInterceptor;
 
-use crate::retry_classification::grpc::classify_tonic_status;
-use opentelemetry_sdk::retry::{retry_with_backoff, RetryPolicy};
+use opentelemetry_sdk::retry::RetryPolicy;
 use opentelemetry_sdk::runtime::Tokio;
 
 pub(crate) struct TonicTracesClient {
@@ -75,10 +74,10 @@ impl SpanExporter for TonicTracesClient {
     async fn export(&self, batch: Vec<SpanData>) -> OTelSdkResult {
         let batch = Arc::new(batch);
 
-        match retry_with_backoff(
+        match super::tonic_retry_with_backoff(
             Tokio,
             self.retry_policy.clone(),
-            classify_tonic_status,
+            crate::retry_classification::grpc::classify_tonic_status,
             "TonicTracesClient.Export",
             || async {
                 let batch_clone = Arc::clone(&batch);