From 282cbb18beae024f935a3aa5d3280ff79ff1957b Mon Sep 17 00:00:00 2001
From: JimMoen <LnJimMoen@outlook.com>
Date: Wed, 3 Apr 2024 17:35:49 +0800
Subject: [PATCH] fix: cpu usage and idle use two decimal places

- prometheus
- opentelemetry
---
 apps/emqx_management/src/emqx_mgmt.erl                 | 4 +++-
 apps/emqx_opentelemetry/src/emqx_opentelemetry.app.src | 2 +-
 apps/emqx_opentelemetry/src/emqx_otel_cpu_sup.erl      | 4 +++-
 changes/fix-12844.en.md                                | 1 +
 4 files changed, 8 insertions(+), 3 deletions(-)
 create mode 100644 changes/fix-12844.en.md

diff --git a/apps/emqx_management/src/emqx_mgmt.erl b/apps/emqx_management/src/emqx_mgmt.erl
index 35908d3bd..e46658619 100644
--- a/apps/emqx_management/src/emqx_mgmt.erl
+++ b/apps/emqx_management/src/emqx_mgmt.erl
@@ -221,7 +221,9 @@ vm_stats('cpu') ->
     case emqx_vm:cpu_util([CpuUtilArg]) of
         %% return 0.0 when `emqx_cpu_sup_worker` is not started
         {all, Use, Idle, _} ->
-            [{cpu_use, Use}, {cpu_idle, Idle}];
+            NUse = floor(Use * 100) / 100,
+            NIdle = ceil(Idle * 100) / 100,
+            [{cpu_use, NUse}, {cpu_idle, NIdle}];
         _ ->
             [{cpu_use, 0}, {cpu_idle, 0}]
     end;
diff --git a/apps/emqx_opentelemetry/src/emqx_opentelemetry.app.src b/apps/emqx_opentelemetry/src/emqx_opentelemetry.app.src
index 81631b03a..cb7c7d32a 100644
--- a/apps/emqx_opentelemetry/src/emqx_opentelemetry.app.src
+++ b/apps/emqx_opentelemetry/src/emqx_opentelemetry.app.src
@@ -1,6 +1,6 @@
 {application, emqx_opentelemetry, [
     {description, "OpenTelemetry for EMQX Broker"},
-    {vsn, "0.2.4"},
+    {vsn, "0.2.5"},
     {registered, []},
     {mod, {emqx_otel_app, []}},
     {applications, [
diff --git a/apps/emqx_opentelemetry/src/emqx_otel_cpu_sup.erl b/apps/emqx_opentelemetry/src/emqx_otel_cpu_sup.erl
index fc67831be..54f88ad99 100644
--- a/apps/emqx_opentelemetry/src/emqx_otel_cpu_sup.erl
+++ b/apps/emqx_opentelemetry/src/emqx_otel_cpu_sup.erl
@@ -119,7 +119,9 @@ code_change(_OldVsn, State, _Extra) ->
 refresh(#{interval := Interval} = State) ->
     NState =
         case cpu_sup:util([]) of
-            {all, U, I, _} ->
+            {all, Use, Idle, _} ->
+                U = floor(Use * 100) / 100,
+                I = ceil(Idle * 100) / 100,
                 State#{'cpu.use' => U, 'cpu.idle' => I};
             _ ->
                 State#{'cpu.use' => 0, 'cpu.idle' => 0}
diff --git a/changes/fix-12844.en.md b/changes/fix-12844.en.md
new file mode 100644
index 000000000..851c877ac
--- /dev/null
+++ b/changes/fix-12844.en.md
@@ -0,0 +1 @@
+CPU usage/idle statistics values are only retained with 2 decimal precision. This affects Prometheus statistical metrics and OpenTelemetry governance metrics.