-import { DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS } from '../../utils'
+import {
+ DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
+ DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+} from '../../utils'
import type { IPool } from '../pool'
-import type { IWorker } from '../worker'
+import type { IWorker, StrategyData } from '../worker'
import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy'
-import type {
- IWorkerChoiceStrategy,
- RequiredStatistics,
- WorkerChoiceStrategyOptions
+import {
+ type IWorkerChoiceStrategy,
+ Measurements,
+ type TaskStatisticsRequirements,
+ type WorkerChoiceStrategyOptions
} from './selection-strategies-types'
-/**
- * Worker virtual task timestamp.
- */
-interface WorkerVirtualTaskTimestamp {
- start: number
- end: number
-}
-
/**
* Selects the next worker with a fair share scheduling algorithm.
* Loosely modeled after the fair queueing algorithm: https://en.wikipedia.org/wiki/Fair_queuing.
*
* @typeParam Worker - Type of worker which manages the strategy.
- * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
- * @typeParam Response - Type of execution response. This can only be serializable data.
+ * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
+ * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
*/
export class FairShareWorkerChoiceStrategy<
Worker extends IWorker,
extends AbstractWorkerChoiceStrategy<Worker, Data, Response>
implements IWorkerChoiceStrategy {
/** @inheritDoc */
- public readonly requiredStatistics: RequiredStatistics = {
- runTime: true,
- avgRunTime: true,
- medRunTime: false
+ public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
+ runTime: {
+ aggregate: true,
+ average: true,
+ median: false
+ },
+ waitTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
+ elu: {
+ aggregate: true,
+ average: true,
+ median: false
+ }
}
- /**
- * Worker last virtual task execution timestamp.
- */
- private readonly workerLastVirtualTaskTimestamp: Map<
- number,
- WorkerVirtualTaskTimestamp
- > = new Map<number, WorkerVirtualTaskTimestamp>()
-
/** @inheritDoc */
public constructor (
pool: IPool<Worker, Data, Response>,
opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
) {
super(pool, opts)
- this.checkOptions(opts)
+ this.setTaskStatisticsRequirements(this.opts)
}
/** @inheritDoc */
public reset (): boolean {
- this.workerLastVirtualTaskTimestamp.clear()
+ for (const workerNode of this.pool.workerNodes) {
+ delete workerNode.strategyData?.virtualTaskEndTimestamp
+ }
return true
}
/** @inheritDoc */
- public choose (): number {
- let minWorkerVirtualTaskEndTimestamp = Infinity
- let chosenWorkerNodeKey!: number
- for (const [index] of this.pool.workerNodes.entries()) {
- this.computeWorkerLastVirtualTaskTimestamp(index)
- const workerLastVirtualTaskEndTimestamp =
- this.workerLastVirtualTaskTimestamp.get(index)?.end ?? 0
- if (
- workerLastVirtualTaskEndTimestamp < minWorkerVirtualTaskEndTimestamp
- ) {
- minWorkerVirtualTaskEndTimestamp = workerLastVirtualTaskEndTimestamp
- chosenWorkerNodeKey = index
- }
+ public update (workerNodeKey: number): boolean {
+ this.pool.workerNodes[workerNodeKey].strategyData = {
+ virtualTaskEndTimestamp:
+ this.computeWorkerNodeVirtualTaskEndTimestamp(workerNodeKey)
}
- return chosenWorkerNodeKey
+ return true
}
/** @inheritDoc */
- public remove (workerNodeKey: number): boolean {
- const deleted = this.workerLastVirtualTaskTimestamp.delete(workerNodeKey)
- for (const [key, value] of this.workerLastVirtualTaskTimestamp.entries()) {
- if (key > workerNodeKey) {
- this.workerLastVirtualTaskTimestamp.set(key - 1, value)
- }
- }
- return deleted
+ public choose (): number | undefined {
+ this.setPreviousWorkerNodeKey(this.nextWorkerNodeKey)
+ this.nextWorkerNodeKey = this.fairShareNextWorkerNodeKey()
+ return this.nextWorkerNodeKey
+ }
+
+ /** @inheritDoc */
+ public remove (): boolean {
+ return true
+ }
+
+ private fairShareNextWorkerNodeKey (): number | undefined {
+ return this.pool.workerNodes.reduce(
+ (minWorkerNodeKey, workerNode, workerNodeKey, workerNodes) => {
+ if (workerNode.strategyData?.virtualTaskEndTimestamp == null) {
+ workerNode.strategyData = {
+ virtualTaskEndTimestamp:
+ this.computeWorkerNodeVirtualTaskEndTimestamp(workerNodeKey)
+ }
+ }
+ return (workerNode.strategyData.virtualTaskEndTimestamp as number) <
+ ((workerNodes[minWorkerNodeKey].strategyData as StrategyData)
+ .virtualTaskEndTimestamp as number)
+ ? workerNodeKey
+ : minWorkerNodeKey
+ },
+ 0
+ )
}
/**
- * Computes worker last virtual task timestamp.
+ * Computes the worker node key virtual task end timestamp.
*
* @param workerNodeKey - The worker node key.
+ * @returns The worker node key virtual task end timestamp.
*/
- private computeWorkerLastVirtualTaskTimestamp (workerNodeKey: number): void {
- const workerVirtualTaskStartTimestamp = Math.max(
- performance.now(),
- this.workerLastVirtualTaskTimestamp.get(workerNodeKey)?.end ?? -Infinity
+ private computeWorkerNodeVirtualTaskEndTimestamp (
+ workerNodeKey: number
+ ): number {
+ return this.getWorkerNodeVirtualTaskEndTimestamp(
+ workerNodeKey,
+ this.getWorkerNodeVirtualTaskStartTimestamp(workerNodeKey)
)
- const workerVirtualTaskTRunTime = this.requiredStatistics.medRunTime
- ? this.pool.workerNodes[workerNodeKey].tasksUsage.medRunTime
- : this.pool.workerNodes[workerNodeKey].tasksUsage.avgRunTime
- this.workerLastVirtualTaskTimestamp.set(workerNodeKey, {
- start: workerVirtualTaskStartTimestamp,
- end: workerVirtualTaskStartTimestamp + (workerVirtualTaskTRunTime ?? 0)
- })
+ }
+
+ private getWorkerNodeVirtualTaskEndTimestamp (
+ workerNodeKey: number,
+ workerNodeVirtualTaskStartTimestamp: number
+ ): number {
+ const workerNodeTaskRunTime =
+ this.opts.measurement === Measurements.elu
+ ? this.getWorkerNodeTaskElu(workerNodeKey)
+ : this.getWorkerNodeTaskRunTime(workerNodeKey)
+ return workerNodeVirtualTaskStartTimestamp + workerNodeTaskRunTime
+ }
+
+ private getWorkerNodeVirtualTaskStartTimestamp (
+ workerNodeKey: number
+ ): number {
+ const virtualTaskEndTimestamp =
+ this.pool.workerNodes[workerNodeKey]?.strategyData
+ ?.virtualTaskEndTimestamp
+ const now = performance.now()
+ return now < (virtualTaskEndTimestamp ?? -Infinity)
+ ? (virtualTaskEndTimestamp as number)
+ : now
}
}