open-nomad/client/stats/cpu.go
2023-04-10 15:36:59 +00:00

94 lines
2.3 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package stats
import (
"runtime"
"time"
shelpers "github.com/hashicorp/nomad/helper/stats"
"github.com/shirou/gopsutil/v3/cpu"
)
// CpuStats calculates cpu usage percentage
type CpuStats struct {
prevCpuTime float64
prevTime time.Time
totalCpus int
}
// NewCpuStats returns a cpu stats calculator
func NewCpuStats() *CpuStats {
numCpus := runtime.NumCPU()
cpuStats := &CpuStats{
totalCpus: numCpus,
}
return cpuStats
}
// Percent calculates the cpu usage percentage based on the current cpu usage
// and the previous cpu usage where usage is given as time in nanoseconds spend
// in the cpu
func (c *CpuStats) Percent(cpuTime float64) float64 {
now := time.Now()
if c.prevCpuTime == 0.0 {
// invoked first time
c.prevCpuTime = cpuTime
c.prevTime = now
return 0.0
}
timeDelta := now.Sub(c.prevTime).Nanoseconds()
ret := c.calculatePercent(c.prevCpuTime, cpuTime, timeDelta)
c.prevCpuTime = cpuTime
c.prevTime = now
return ret
}
// TicksConsumed calculates the total ticks consumes by the process across all
// cpu cores
func (c *CpuStats) TicksConsumed(percent float64) float64 {
return (percent / 100) * float64(shelpers.TotalTicksAvailable()) / float64(c.totalCpus)
}
func (c *CpuStats) calculatePercent(t1, t2 float64, timeDelta int64) float64 {
vDelta := t2 - t1
if timeDelta <= 0 || vDelta <= 0.0 {
return 0.0
}
overall_percent := (vDelta / float64(timeDelta)) * 100.0
return overall_percent
}
func (h *HostStatsCollector) collectCPUStats() (cpus []*CPUStats, totalTicks float64, err error) {
ticksConsumed := 0.0
cpuStats, err := cpu.Times(true)
if err != nil {
return nil, 0.0, err
}
cs := make([]*CPUStats, len(cpuStats))
for idx, cpuStat := range cpuStats {
percentCalculator, ok := h.statsCalculator[cpuStat.CPU]
if !ok {
percentCalculator = NewHostCpuStatsCalculator()
h.statsCalculator[cpuStat.CPU] = percentCalculator
}
idle, user, system, total := percentCalculator.Calculate(cpuStat)
cs[idx] = &CPUStats{
CPU: cpuStat.CPU,
User: user,
System: system,
Idle: idle,
Total: total,
}
ticksConsumed += (total / 100.0) * (float64(shelpers.TotalTicksAvailable()) / float64(len(cpuStats)))
}
return cs, ticksConsumed, nil
}