Add system CPU metrics to metrics-v3 (#19560)

endpoint: /minio/metrics/v3/system/cpu

metrics:
- minio_system_cpu_avg_idle
- minio_system_cpu_avg_iowait
- minio_system_cpu_load
- minio_system_cpu_load_perc
- minio_system_cpu_nice
- minio_system_cpu_steal
- minio_system_cpu_system
- minio_system_cpu_user

cmd/metrics-v3-system-cpu.go

@@ -0,0 +1,82 @@
+// Copyright (c) 2015-2024 MinIO, Inc.
+//
+// # This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package cmd
+
+import (
+	"context"
+	"math"
+)
+
+const (
+	sysCPUAvgIdle   = "avg_idle"
+	sysCPUAvgIOWait = "avg_iowait"
+	sysCPULoad      = "load"
+	sysCPULoadPerc  = "load_perc"
+	sysCPUNice      = "nice"
+	sysCPUSteal     = "steal"
+	sysCPUSystem    = "system"
+	sysCPUUser      = "user"
+)
+
+var (
+	sysCPUAvgIdleMD   = NewGaugeMD(sysCPUAvgIdle, "Average CPU idle time")
+	sysCPUAvgIOWaitMD = NewGaugeMD(sysCPUAvgIOWait, "Average CPU IOWait time")
+	sysCPULoadMD      = NewGaugeMD(sysCPULoad, "CPU load average 1min")
+	sysCPULoadPercMD  = NewGaugeMD(sysCPULoadPerc, "CPU load average 1min (percentage)")
+	sysCPUNiceMD      = NewGaugeMD(sysCPUNice, "CPU nice time")
+	sysCPUStealMD     = NewGaugeMD(sysCPUSteal, "CPU steal time")
+	sysCPUSystemMD    = NewGaugeMD(sysCPUSystem, "CPU system time")
+	sysCPUUserMD      = NewGaugeMD(sysCPUUser, "CPU user time")
+)
+
+// loadCPUMetrics - `MetricsLoaderFn` for system CPU metrics.
+func loadCPUMetrics(ctx context.Context, m MetricValues, c *metricsCache) error {
+	cpuMetrics, _ := c.cpuMetrics.Get()
+
+	if cpuMetrics.LoadStat != nil {
+		m.Set(sysCPULoad, cpuMetrics.LoadStat.Load1)
+		perc := cpuMetrics.LoadStat.Load1 * 100 / float64(cpuMetrics.CPUCount)
+		m.Set(sysCPULoadPerc, math.Round(perc*100)/100)
+	}
+
+	ts := cpuMetrics.TimesStat
+	tot := ts.User + ts.System + ts.Idle + ts.Iowait + ts.Nice + ts.Steal
+	cpuUserVal := math.Round(ts.User/tot*100*100) / 100
+	m.Set(sysCPUUser, cpuUserVal)
+	cpuSystemVal := math.Round(ts.System/tot*100*100) / 100
+	m.Set(sysCPUSystem, cpuSystemVal)
+	cpuNiceVal := math.Round(ts.Nice/tot*100*100) / 100
+	m.Set(sysCPUNice, cpuNiceVal)
+	cpuStealVal := math.Round(ts.Steal/tot*100*100) / 100
+	m.Set(sysCPUSteal, cpuStealVal)
+
+	// metrics-resource.go runs a job to collect resource metrics including their Avg values and
+	// stores them in resourceMetricsMap. We can use it to get the Avg values of CPU idle and IOWait.
+	cpuResourceMetrics, found := resourceMetricsMap[cpuSubsystem]
+	if found {
+		if cpuIdleMetric, ok := cpuResourceMetrics[getResourceKey(cpuIdle, nil)]; ok {
+			avgVal := math.Round(cpuIdleMetric.Avg*100) / 100
+			m.Set(sysCPUAvgIdle, avgVal)
+		}
+		if cpuIOWaitMetric, ok := cpuResourceMetrics[getResourceKey(cpuIOWait, nil)]; ok {
+			avgVal := math.Round(cpuIOWaitMetric.Avg*100) / 100
+			m.Set(sysCPUAvgIOWait, avgVal)
+		}
+	}
+	return nil
+}