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")

		cpuNice:           "CPU nice time",
		cpuLoad1:          "CPU load average 1min",
		cpuLoad5:          "CPU load average 5min",
		cpuLoad15:         "CPU load average 15min",
		cpuLoad1Perc:      "CPU load average 1min (perentage)",
		cpuLoad5Perc:      "CPU load average 5min (percentage)",
		cpuLoad15Perc:     "CPU load average 15min (percentage)",
	}
	resourceMetricsGroups = []*MetricsGroupV2{

}

// exponentialMovingAverage calculates the exponential moving average
func exponentialMovingAverage(beta, previousAvg, incrementAvg float64) float64 {
	return (1-beta)*incrementAvg + beta*previousAvg
}

// getExpMovingAvgBytesPerSecond returns the exponential moving average for the bucket in bytes
func (m *bucketMeasurement) getExpMovingAvgBytesPerSecond() float64 {
	m.lock.Lock()

	Rotational bool
	Metrics    DiskMetrics
	Error      string // carries the error over the network
}

// DiskMetrics has the information about XL Storage APIs
// the number of calls of each API and the moving average of
// the duration of each API.
type DiskMetrics struct {
	LastMinute              map[string]AccElem `json:"apiLatencies,omitempty"`
	APICalls                map[string]uint64  `json:"apiCalls,omitempty"`

	currTransferRate   MetricName = "current_transfer_rate"
	avgTransferRate    MetricName = "average_transfer_rate"
	maxTransferRate    MetricName = "max_transfer_rate"
	credentialErrors   MetricName = "credential_errors"

	currLinkLatency MetricName = "current_link_latency_ms"
	avgLinkLatency  MetricName = "average_link_latency_ms"
	maxLinkLatency  MetricName = "max_link_latency_ms"

	dialect := DB.Dialector.Name()
	switch dialect {
	case "mysql", "sqlserver":
		// these dialects do not support the "returning" clause
		return
	default:
		// This user struct will leverage the existing users table, but override
		// the Name field to default to null.
		type user struct {
			gorm.Model
			Name string `gorm:"default:null"`
		}
		u1 := user{}

			// Experiments (using IndexPeriodic) suggest
			// the cutover is about 16 byte skips.
			// TODO: if large prefixes of sep are matching
			// we should cutover at even larger average skips,
			// because Equal becomes that much more expensive.
			// This code does not take that effect into account.
			j := bytealg.IndexRabinKarp(s[i:], sep)
			if j < 0 {
				return -1
			}

}

// exponentialMovingAverage calculates the exponential moving average
func exponentialMovingAverage(beta, previousAvg, incrementAvg float64) float64 {
	return (1-beta)*incrementAvg + beta*previousAvg
}

// getExpMovingAvgBytesPerSecond returns the exponential moving average for the bucket/target in bytes
func (m *rateMeasurement) getExpMovingAvgBytesPerSecond() float64 {
	m.lock.Lock()

		allDriveLabels...)
	driveWaitingIOMD = NewGaugeMD(driveWaitingIO,
		"Total waiting I/O operations on a drive", allDriveLabels...)
	driveAPILatencyMD = NewGaugeMD(driveAPILatencyMicros,
		"Average last minute latency in µs for drive API storage operations",
		append(allDriveLabels, apiL)...)
	driveHealingMD = NewGaugeMD(driveHealing,
		"Is it healing?", allDriveLabels...)
	driveOnlineMD = NewGaugeMD(driveOnline,

	pluginAuthnServiceSuccAvgRttMsMinuteMD   = NewCounterMD(pluginAuthnServiceSuccAvgRttMsMinute, "When plugin authentication is configured, returns average round-trip-time of successful requests in the last full minute")