From 81d1464d7ab4b67031692ae81cabb212869489e6 Mon Sep 17 00:00:00 2001
From: kosuke-fujishiro <kosuke.fujishiro09@gmail.com>
Date: Thu, 22 Jan 2026 16:13:57 +0900
Subject: [PATCH] fix: spawn process metrics as background task

init_process_observer runs an infinite loop to collect system metrics,
so it must be spawned as a background task instead of being awaited.
Also add gzip-tonic feature for OTLP compression support.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 Cargo.lock         |  1 +
 Cargo.toml         |  1 +
 src/cli/metrics.rs | 16 ++++++++++------
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 209f542f0b..7c3f0aa079 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6179,6 +6179,7 @@ dependencies = [
  "axum",
  "base64 0.22.1",
  "bytes",
+ "flate2",
  "h2 0.4.13",
  "http 1.4.0",
  "http-body 1.0.1",
diff --git a/Cargo.toml b/Cargo.toml
index d926bc2eec..247ef3ccb1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -170,6 +170,7 @@ opentelemetry-otlp = { version = "0.28", features = [
   "metrics",
   # required to make grpc requests
   "grpc-tonic",
+  "gzip-tonic",
   "tls-roots",
 ], optional = true }
 opentelemetry-prometheus = "0.28"
diff --git a/src/cli/metrics.rs b/src/cli/metrics.rs
index edcda325ec..267f1ff8ee 100644
--- a/src/cli/metrics.rs
+++ b/src/cli/metrics.rs
@@ -1,4 +1,4 @@
-use anyhow::{anyhow, Result};
+use anyhow::Result;
 
 use crate::core::runtime::TargetRuntime;
 
@@ -18,17 +18,21 @@ fn cache_metrics(runtime: &TargetRuntime) -> Result<()> {
     Ok(())
 }
 
-async fn process_resources_metrics() -> Result<()> {
+fn process_resources_metrics() {
     let meter = opentelemetry::global::meter("process-resources");
 
-    opentelemetry_system_metrics::init_process_observer(meter)
-        .await
-        .map_err(|err| anyhow!(err))
+    // init_process_observer runs an infinite loop to collect system metrics,
+    // so it must be spawned as a background task
+    tokio::spawn(async move {
+        if let Err(err) = opentelemetry_system_metrics::init_process_observer(meter).await {
+            tracing::warn!("process_resources_metrics failed: {}", err);
+        }
+    });
 }
 
 pub async fn init_metrics(runtime: &TargetRuntime) -> Result<()> {
     cache_metrics(runtime)?;
-    process_resources_metrics().await?;
+    process_resources_metrics();
 
     Ok(())
 }