From 8a6306954e77ca521483fa3a53aedabeaf94f04a Mon Sep 17 00:00:00 2001
From: Dmitry Dementev <me@dementev.space>
Date: Sun, 8 Feb 2026 22:48:36 +0300
Subject: [PATCH] fix(monitoring): use delta() instead of rate() for CPU gauge
 metric

Fix Grafana warning about using rate() on gauge metric:
- ClickHouseProfileEvents_OSCPUVirtualTimeMicroseconds is a gauge, not counter
- rate() should only be used with counters; using delta() instead
- Add explicit datasource block for consistency

API verified via Context7:
- /prometheus/docs: rate() should never be used on gauges
---
 .../provisioning/dashboards/clickhouse-overview.json        | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/configs/grafana/provisioning/dashboards/clickhouse-overview.json b/configs/grafana/provisioning/dashboards/clickhouse-overview.json
index 454acd4..bc863dc 100644
--- a/configs/grafana/provisioning/dashboards/clickhouse-overview.json
+++ b/configs/grafana/provisioning/dashboards/clickhouse-overview.json
@@ -116,7 +116,11 @@
       },
       "targets": [
         {
-          "expr": "rate(ClickHouseProfileEvents_OSCPUVirtualTimeMicroseconds[1m]) / 1000000 / scalar(count({__name__=~\"ClickHouseAsyncMetrics_CPUFrequencyMHz_.*\"})) * 100",
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus_uid"
+          },
+          "expr": "delta(ClickHouseProfileEvents_OSCPUVirtualTimeMicroseconds[1m]) / 60 / 1000000 / scalar(count({__name__=~\"ClickHouseAsyncMetrics_CPUFrequencyMHz_.*\"})) * 100",
           "refId": "A"
         }
       ],