chore: use DefaultHasher to spread out nano time jitter

Author: scottgerring

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

@@ -22,10 +22,10 @@ use std::str::FromStr;
 use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
-#[cfg(feature = "experimental-http-retry")]
-use crate::retry_classification::http::classify_http_error;
 #[cfg(feature = "experimental-http-retry")]
 use crate::retry::{RetryErrorType, RetryPolicy};
+#[cfg(feature = "experimental-http-retry")]
+use crate::retry_classification::http::classify_http_error;
 
 // Shared HTTP retry functionality
 /// HTTP-specific error wrapper for retry classification
@@ -1492,8 +1492,8 @@ mod tests {
         #[test]
         fn test_with_retry_policy() {
             use super::super::HttpExporterBuilder;
-            use crate::WithHttpConfig;
             use crate::retry::RetryPolicy;
+            use crate::WithHttpConfig;
 
             let custom_policy = RetryPolicy {
                 max_retries: 5,

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

@@ -856,8 +856,8 @@ mod tests {
     #[cfg(feature = "experimental-grpc-retry")]
     #[test]
     fn test_with_retry_policy() {
-        use crate::WithTonicConfig;
         use crate::retry::RetryPolicy;
+        use crate::WithTonicConfig;
 
         let custom_policy = RetryPolicy {
             max_retries: 5,

opentelemetry-otlp/src/retry.rs

@@ -8,16 +8,32 @@
 //! retries. The function uses error classification to determine retry behavior and can honor
 //! server-provided throttling hints.
 
-#[cfg(any(feature = "experimental-grpc-retry", feature = "experimental-http-retry"))]
+#[cfg(any(
+    feature = "experimental-grpc-retry",
+    feature = "experimental-http-retry"
+))]
 use opentelemetry::otel_warn;
-#[cfg(any(feature = "experimental-grpc-retry", feature = "experimental-http-retry"))]
+#[cfg(any(
+    feature = "experimental-grpc-retry",
+    feature = "experimental-http-retry"
+))]
 use std::future::Future;
-use std::hash::DefaultHasher;
+#[cfg(any(
+    feature = "experimental-grpc-retry",
+    feature = "experimental-http-retry"
+))]
+use std::hash::{DefaultHasher, Hasher};
 use std::time::Duration;
-#[cfg(any(feature = "experimental-grpc-retry", feature = "experimental-http-retry"))]
+#[cfg(any(
+    feature = "experimental-grpc-retry",
+    feature = "experimental-http-retry"
+))]
 use std::time::SystemTime;
 
-#[cfg(any(feature = "experimental-grpc-retry", feature = "experimental-http-retry"))]
+#[cfg(any(
+    feature = "experimental-grpc-retry",
+    feature = "experimental-http-retry"
+))]
 use opentelemetry_sdk::runtime::Runtime;
 
 /// Classification of errors for retry purposes.
@@ -47,11 +63,17 @@ pub struct RetryPolicy {
 
 /// A runtime stub for when experimental_async_runtime is not enabled.
 /// This allows retry policy to be configured but no actual retries occur.
-#[cfg(not(any(feature = "experimental-grpc-retry", feature = "experimental-http-retry")))]
+#[cfg(not(any(
+    feature = "experimental-grpc-retry",
+    feature = "experimental-http-retry"
+)))]
 #[derive(Debug, Clone, Default)]
 pub struct NoOpRuntime;
 
-#[cfg(not(any(feature = "experimental-grpc-retry", feature = "experimental-http-retry")))]
+#[cfg(not(any(
+    feature = "experimental-grpc-retry",
+    feature = "experimental-http-retry"
+)))]
 impl NoOpRuntime {
     /// Creates a new no-op runtime.
     pub fn new() -> Self {
@@ -60,17 +82,19 @@ impl NoOpRuntime {
 }
 
 // Generates a random jitter value up to max_jitter
-#[cfg(any(feature = "experimental-grpc-retry", feature = "experimental-http-retry"))]
+#[cfg(any(
+    feature = "experimental-grpc-retry",
+    feature = "experimental-http-retry"
+))]
 fn generate_jitter(max_jitter: u64) -> u64 {
-    let now = SystemTime::now();
-    let nanos = now
+    let nanos = SystemTime::now()
         .duration_since(SystemTime::UNIX_EPOCH)
         .unwrap()
         .subsec_nanos();
 
-    let hasher = DefaultHasher::default();
-
-    nanos as u64 % (max_jitter + 1)
+    let mut hasher = DefaultHasher::default();
+    hasher.write_u32(nanos);
+    hasher.finish() % (max_jitter + 1)
 }
 
 /// Retries the given operation with exponential backoff, jitter, and error classification.
@@ -90,7 +114,10 @@ fn generate_jitter(max_jitter: u64) -> u64 {
 ///
 /// A `Result` containing the operation's result or an error if max retries are reached
 /// or a non-retryable error occurs.
-#[cfg(any(feature = "experimental-grpc-retry", feature = "experimental-http-retry"))]
+#[cfg(any(
+    feature = "experimental-grpc-retry",
+    feature = "experimental-http-retry"
+))]
 pub async fn retry_with_backoff<R, F, Fut, T, E, C>(
     runtime: R,
     policy: RetryPolicy,
@@ -151,7 +178,10 @@ where
 
 /// No-op retry function for when experimental_async_runtime is not enabled.
 /// This function will execute the operation exactly once without any retries.
-#[cfg(not(any(feature = "experimental-grpc-retry", feature = "experimental-http-retry")))]
+#[cfg(not(any(
+    feature = "experimental-grpc-retry",
+    feature = "experimental-http-retry"
+)))]
 pub async fn retry_with_backoff<R, F, Fut, T, E, C>(
     _runtime: R,
     _policy: RetryPolicy,

opentelemetry-otlp/src/retry_classification.rs

@@ -221,8 +221,8 @@ mod tests {
     // Tests for gRPC error classification using public interface
     #[cfg(feature = "grpc-tonic")]
     mod grpc_tests {
-        use crate::retry_classification::grpc::classify_tonic_status;
         use crate::retry::RetryErrorType;
+        use crate::retry_classification::grpc::classify_tonic_status;
         use tonic_types::{ErrorDetails, StatusExt};
 
         #[test]

opentelemetry-sdk/src/lib.rs

@@ -167,4 +167,3 @@ impl<T> From<std::sync::PoisonError<T>> for InMemoryExporterError {
         InMemoryExporterError::InternalFailure(format!("Mutex poison error: {err}"))
     }
 }
-