From 9a7e823e5be340e6e54bfac60edc6e1e0fd72d49 Mon Sep 17 00:00:00 2001
From: keith thornhill <keitht@openai.com>
Date: Mon, 20 Jul 2026 16:21:11 +0000
Subject: [PATCH] Extend second-based latency histogram buckets (#34375)

## Why

Requests longer than 10 seconds were grouped into the overflow bucket, limiting visibility into long-running request latency.

## What changed

Add second-based duration histogram boundaries at 12, 15, 20, 30, 60, and 120 seconds.

## Testing

Extend the duration histogram test to cover every new boundary and a 121-second overflow value.

GitOrigin-RevId: 063a5d397dbd37d3b3940c7a1632b7b479e874a4
---
 codex-rs/otel/src/metrics/client.rs |  3 ++-
 codex-rs/otel/tests/suite/timing.rs | 17 ++++++++++++++---
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/codex-rs/otel/src/metrics/client.rs b/codex-rs/otel/src/metrics/client.rs
index ec90584e0a..b0ba57a23f 100644
--- a/codex-rs/otel/src/metrics/client.rs
+++ b/codex-rs/otel/src/metrics/client.rs
@@ -53,7 +53,8 @@ const MILLISECOND_DURATION_BOUNDARIES: &[f64] = &[
 ];
 const SECOND_DURATION_UNIT: &str = "s";
 const SECOND_DURATION_BOUNDARIES: &[f64] = &[
-    0.0, 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1.0, 2.5, 5.0, 7.5, 10.0,
+    0.0, 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1.0, 2.5, 5.0, 7.5, 10.0, 12.0,
+    15.0, 20.0, 30.0, 60.0, 120.0,
 ];
 
 #[derive(Debug, Eq, Hash, PartialEq)]
diff --git a/codex-rs/otel/tests/suite/timing.rs b/codex-rs/otel/tests/suite/timing.rs
index 02259b6c72..2b119f4eb3 100644
--- a/codex-rs/otel/tests/suite/timing.rs
+++ b/codex-rs/otel/tests/suite/timing.rs
@@ -48,6 +48,7 @@ fn record_duration_keeps_whole_millisecond_behavior() -> Result<()> {
     Ok(())
 }
 
+/// Keeps long-running requests observable instead of collapsing their latency into the overflow bucket.
 #[test]
 fn record_duration_seconds_uses_fractional_seconds_and_scaled_buckets() -> Result<()> {
     let (metrics, exporter) = build_metrics_with_defaults(&[])?;
@@ -56,6 +57,13 @@ fn record_duration_seconds_uses_fractional_seconds_and_scaled_buckets() -> Resul
         Duration::from_millis(200),
         Duration::from_secs(1),
         Duration::from_millis(4900),
+        Duration::from_secs(12),
+        Duration::from_secs(15),
+        Duration::from_secs(20),
+        Duration::from_secs(30),
+        Duration::from_secs(60),
+        Duration::from_secs(120),
+        Duration::from_secs(121),
     ] {
         metrics.record_duration_seconds_with_description(
             "codex.request_duration_seconds",
@@ -73,14 +81,17 @@ fn record_duration_seconds_uses_fractional_seconds_and_scaled_buckets() -> Resul
         bounds,
         vec![
             0.0, 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1.0, 2.5, 5.0, 7.5, 10.0,
+            12.0, 15.0, 20.0, 30.0, 60.0, 120.0,
         ]
     );
     assert_eq!(
         bucket_counts,
-        vec![0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0]
+        vec![
+            0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1
+        ]
     );
-    assert!((sum - 6.1).abs() < f64::EPSILON * 8.0);
-    assert_eq!(count, 3);
+    assert!((sum - 384.1).abs() < f64::EPSILON * 512.0);
+    assert_eq!(count, 10);
     let metric = crate::harness::find_metric(&resource_metrics, "codex.request_duration_seconds")
         .expect("codex.request_duration_seconds metric should exist");
     assert_eq!(metric.unit(), "s");