From ac2c74e5f3c5dd2ecb8a15cff7e7893b4e8b152c Mon Sep 17 00:00:00 2001
From: Min RK <benjaminrk@gmail.com>
Date: Thu, 9 Nov 2023 09:23:50 +0100
Subject: [PATCH] increase resolution of event-loop-tick metric to 5ms below
 50ms

---
 jupyterhub/metrics.py | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/jupyterhub/metrics.py b/jupyterhub/metrics.py
index 1389d212..c8e91ea0 100644
--- a/jupyterhub/metrics.py
+++ b/jupyterhub/metrics.py
@@ -236,6 +236,30 @@ EVENT_LOOP_INTERVAL_SECONDS = Histogram(
     'event_loop_interval_seconds',
     'Distribution of measured event loop intervals',
     namespace=metrics_prefix,
+    # Increase resolution to 5ms below 50ms
+    # because this is where we are most sensitive.
+    # No need to have buckets below 25, since we only measure every 20ms.
+    buckets=[
+        # 5ms from 25-50ms
+        25e-3,
+        30e-3,
+        35e-3,
+        40e-3,
+        45e-3,
+        50e-3,
+        # from here, default prometheus buckets
+        75e-3,
+        0.1,
+        0.25,
+        0.5,
+        0.75,
+        1,
+        2.5,
+        5,
+        7.5,
+        10,
+        float("inf"),
+    ],
 )