kyo.scheduler.regulator.Regulator.scala Maven / Gradle / Ivy
package kyo.scheduler.regulator
import java.util.concurrent.atomic.LongAdder
import java.util.function.DoubleSupplier
import kyo.scheduler.InternalTimer
import kyo.scheduler.top.RegulatorStatus
import kyo.scheduler.util.*
import scala.util.control.NonFatal
abstract class Regulator(
loadAvg: DoubleSupplier,
timer: InternalTimer,
config: Config
) {
import config.*
private var step = 0
private val measurements = new MovingStdDev(collectWindow)
private val probesSent = new LongAdder
private val probesCompleted = new LongAdder
private val adjustments = new LongAdder
private val updates = new LongAdder
protected def probe(): Unit
protected def update(diff: Int): Unit
private val collectTask =
timer.schedule(collectInterval)(collect())
private val regulateTask =
timer.schedule(regulateInterval)(adjust())
final private def collect(): Unit = {
try {
probesSent.increment()
probe()
} catch {
case ex if NonFatal(ex) =>
kyo.scheduler.bug(s"${getClass.getSimpleName()} regulator's probe collection has failed.", ex)
}
}
protected def measure(v: Long): Unit = {
probesCompleted.increment()
stats.measurement.observe(Math.max(0, v.toDouble))
synchronized(measurements.observe(v))
}
final private def adjust() = {
try {
adjustments.increment()
val jitter = synchronized(measurements.dev())
val load = loadAvg.getAsDouble()
if (jitter > jitterUpperThreshold) {
if (step < 0) step -= 1
else step = -1
} else if (jitter < jitterLowerThreshold && load >= loadAvgTarget) {
if (step > 0) step += 1
else step = 1
} else
step = 0
if (step != 0) {
val pow = Math.pow(Math.abs(step), stepExp).toInt
val delta =
if (step < 0) -pow
else pow
updates.increment()
update(delta)
}
stats.jitter.observe(jitter)
stats.loadavg.observe(load)
} catch {
case ex if NonFatal(ex) =>
kyo.scheduler.bug(s"${getClass.getSimpleName()} regulator's adjustment has failed.", ex)
}
}
def stop(): Unit = {
collectTask.cancel()
val _ = regulateTask.cancel()
}
protected val statsScope = kyo.scheduler.statsScope.scope("regulator", getClass.getSimpleName().toLowerCase())
private object stats {
val loadavg = statsScope.histogram("loadavg")
val measurement = statsScope.histogram("measurement")
val update = statsScope.histogram("update")
val jitter = statsScope.histogram("jitter")
val gauges = List(
statsScope.gauge("probes_sent")(probesSent.sum().toDouble),
statsScope.gauge("probes_completed")(probesSent.sum().toDouble),
statsScope.gauge("adjustments")(adjustments.sum().toDouble),
statsScope.gauge("updates")(updates.sum.toDouble)
)
}
protected def regulatorStatus(): RegulatorStatus =
RegulatorStatus(
step,
measurements.avg(),
measurements.dev(),
probesSent.sum(),
probesCompleted.sum(),
adjustments.sum(),
updates.sum()
)
}