feat(OTLP): add zstd and gzip compression support to HTTP OTLP exporter (#3092)

Author: scottgerring

opentelemetry-otlp/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## vNext
 
+- Add HTTP compression support with `gzip-http` and `zstd-http` feature flags
+
 ## 0.30.0
 
 Released 2025-May-23

opentelemetry-otlp/Cargo.toml

@@ -43,13 +43,18 @@ serde = { workspace = true, features = ["derive"], optional = true }
 thiserror = { workspace = true }
 serde_json = { workspace = true, optional = true }
 
+# compression dependencies
+flate2 = { version = "1.1.2", optional = true }
+zstd = { version = "0.13", optional = true }
+
 [dev-dependencies]
 tokio-stream = { workspace = true, features = ["net"] }
 opentelemetry_sdk = { workspace = true, features = ["trace", "testing"] }
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
 futures-util = { workspace = true }
 temp-env = { workspace = true }
 tonic = { workspace = true, features = ["router", "server"] }
+async-trait = { workspace = true }
 
 [features]
 # telemetry pillars and functions
@@ -67,6 +72,10 @@ default = ["http-proto", "reqwest-blocking-client", "trace", "metrics", "logs",
 grpc-tonic = ["tonic", "prost", "http", "tokio", "opentelemetry-proto/gen-tonic"]
 gzip-tonic = ["tonic/gzip"]
 zstd-tonic = ["tonic/zstd"]
+
+# http compression
+gzip-http = ["flate2"]
+zstd-http = ["zstd"]
 tls = ["tonic/tls-ring"]
 tls-roots = ["tls", "tonic/tls-native-roots"]
 tls-webpki-roots = ["tls", "tonic/tls-webpki-roots"]

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

@@ -1,4 +1,5 @@
 use super::OtlpHttpClient;
+use http::header::CONTENT_ENCODING;
 use http::{header::CONTENT_TYPE, Method};
 use opentelemetry::otel_debug;
 use opentelemetry_sdk::error::{OTelSdkError, OTelSdkResult};
@@ -14,14 +15,20 @@ impl LogExporter for OtlpHttpClient {
             .clone()
             .ok_or(OTelSdkError::AlreadyShutdown)?;
 
-        let (body, content_type) = self
+        let (body, content_type, content_encoding) = self
             .build_logs_export_body(batch)
             .map_err(OTelSdkError::InternalFailure)?;
 
-        let mut request = http::Request::builder()
+        let mut request_builder = http::Request::builder()
             .method(Method::POST)
             .uri(&self.collector_endpoint)
-            .header(CONTENT_TYPE, content_type)
+            .header(CONTENT_TYPE, content_type);
+
+        if let Some(encoding) = content_encoding {
+            request_builder = request_builder.header(CONTENT_ENCODING, encoding);
+        }
+
+        let mut request = request_builder
             .body(body.into())
             .map_err(|e| OTelSdkError::InternalFailure(e.to_string()))?;
 

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

@@ -19,13 +19,21 @@ impl MetricsClient for OtlpHttpClient {
                 _ => Err(OTelSdkError::AlreadyShutdown),
             })?;
 
-        let (body, content_type) = self.build_metrics_export_body(metrics).ok_or_else(|| {
-            OTelSdkError::InternalFailure("Failed to serialize metrics".to_string())
-        })?;
-        let mut request = http::Request::builder()
+        let (body, content_type, content_encoding) =
+            self.build_metrics_export_body(metrics).ok_or_else(|| {
+                OTelSdkError::InternalFailure("Failed to serialize metrics".to_string())
+            })?;
+
+        let mut request_builder = http::Request::builder()
             .method(Method::POST)
             .uri(&self.collector_endpoint)
-            .header(CONTENT_TYPE, content_type)
+            .header(CONTENT_TYPE, content_type);
+
+        if let Some(encoding) = content_encoding {
+            request_builder = request_builder.header("Content-Encoding", encoding);
+        }
+
+        let mut request = request_builder
             .body(body.into())
             .map_err(|e| OTelSdkError::InternalFailure(format!("{e:?}")))?;