-import { cpus } from 'node:os'
-import type { IPoolInternal } from '../pool-internal'
import type { IWorker } from '../worker'
+import type { IPool } from '../pool'
+import {
+ DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
+ DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+} from '../../utils'
import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy'
import type {
IWorkerChoiceStrategy,
- RequiredStatistics,
+ StrategyPolicy,
+ TaskStatisticsRequirements,
WorkerChoiceStrategyOptions
} from './selection-strategies-types'
-/**
- * Virtual task runtime.
- */
-interface TaskRunTime {
- weight: number
- runTime: number
-}
-
/**
* Selects the next worker with a weighted round robin scheduling algorithm.
* Loosely modeled after the weighted round robin queueing algorithm: https://en.wikipedia.org/wiki/Weighted_round_robin.
*
* @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 response of execution. 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 WeightedRoundRobinWorkerChoiceStrategy<
Worker extends IWorker,
extends AbstractWorkerChoiceStrategy<Worker, Data, Response>
implements IWorkerChoiceStrategy {
/** @inheritDoc */
- public readonly requiredStatistics: RequiredStatistics = {
- runTime: true,
- avgRunTime: true,
- medRunTime: false
+ public readonly strategyPolicy: StrategyPolicy = {
+ useDynamicWorker: true
+ }
+
+ /** @inheritDoc */
+ public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
+ runTime: {
+ aggregate: true,
+ average: true,
+ median: false
+ },
+ waitTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
+ elu: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS
}
- /**
- * Worker node id where the current task will be submitted.
- */
- private currentWorkerNodeId: number = 0
/**
* Default worker weight.
*/
private readonly defaultWorkerWeight: number
/**
- * Workers' virtual task runtime.
+ * Worker virtual task runtime.
*/
- private readonly workersTaskRunTime: Map<number, TaskRunTime> = new Map<
- number,
- TaskRunTime
- >()
+ private workerVirtualTaskRunTime: number = 0
- /**
- * Constructs a worker choice strategy that selects with a weighted round robin scheduling algorithm.
- *
- * @param pool - The pool instance.
- * @param opts - The worker choice strategy options.
- */
+ /** @inheritDoc */
public constructor (
- pool: IPoolInternal<Worker, Data, Response>,
- opts?: WorkerChoiceStrategyOptions
+ pool: IPool<Worker, Data, Response>,
+ opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
) {
super(pool, opts)
- this.defaultWorkerWeight = this.computeWorkerWeight()
- this.initWorkersTaskRunTime()
+ this.setTaskStatisticsRequirements(this.opts)
+ this.defaultWorkerWeight = this.computeDefaultWorkerWeight()
}
/** @inheritDoc */
public reset (): boolean {
- this.currentWorkerNodeId = 0
- this.workersTaskRunTime.clear()
- this.initWorkersTaskRunTime()
+ this.nextWorkerNodeKey = 0
+ this.workerVirtualTaskRunTime = 0
+ return true
+ }
+
+ /** @inheritDoc */
+ public update (): boolean {
return true
}
/** @inheritDoc */
public choose (): number {
- const chosenWorkerNodeKey = this.currentWorkerNodeId
- if (
- this.isDynamicPool &&
- !this.workersTaskRunTime.has(chosenWorkerNodeKey)
- ) {
- this.initWorkerTaskRunTime(chosenWorkerNodeKey)
- }
- const workerTaskRunTime =
- this.workersTaskRunTime.get(chosenWorkerNodeKey)?.runTime ?? 0
- const workerTaskWeight =
- this.workersTaskRunTime.get(chosenWorkerNodeKey)?.weight ??
- this.defaultWorkerWeight
- if (workerTaskRunTime < workerTaskWeight) {
- this.setWorkerTaskRunTime(
- chosenWorkerNodeKey,
- workerTaskWeight,
- workerTaskRunTime +
- (this.getWorkerVirtualTaskRunTime(chosenWorkerNodeKey) ?? 0)
- )
- } else {
- this.currentWorkerNodeId =
- this.currentWorkerNodeId === this.pool.workerNodes.length - 1
- ? 0
- : this.currentWorkerNodeId + 1
- this.setWorkerTaskRunTime(this.currentWorkerNodeId, workerTaskWeight, 0)
- }
+ const chosenWorkerNodeKey = this.nextWorkerNodeKey
+ do {
+ this.weightedRoundRobinNextWorkerNodeKey()
+ } while (!this.isWorkerNodeEligible(this.nextWorkerNodeKey))
return chosenWorkerNodeKey
}
/** @inheritDoc */
public remove (workerNodeKey: number): boolean {
- if (this.currentWorkerNodeId === workerNodeKey) {
+ if (this.nextWorkerNodeKey === workerNodeKey) {
if (this.pool.workerNodes.length === 0) {
- this.currentWorkerNodeId = 0
- } else {
- this.currentWorkerNodeId =
- this.currentWorkerNodeId > this.pool.workerNodes.length - 1
- ? this.pool.workerNodes.length - 1
- : this.currentWorkerNodeId
- }
- }
- const deleted = this.workersTaskRunTime.delete(workerNodeKey)
- for (const [key, value] of this.workersTaskRunTime) {
- if (key > workerNodeKey) {
- this.workersTaskRunTime.set(key - 1, value)
+ this.nextWorkerNodeKey = 0
+ } else if (this.nextWorkerNodeKey > this.pool.workerNodes.length - 1) {
+ this.nextWorkerNodeKey = this.pool.workerNodes.length - 1
}
+ this.workerVirtualTaskRunTime = 0
}
- return deleted
- }
-
- private initWorkersTaskRunTime (): void {
- for (const [index] of this.pool.workerNodes.entries()) {
- this.initWorkerTaskRunTime(index)
- }
- }
-
- private initWorkerTaskRunTime (workerNodeKey: number): void {
- this.setWorkerTaskRunTime(workerNodeKey, this.defaultWorkerWeight, 0)
- }
-
- private setWorkerTaskRunTime (
- workerNodeKey: number,
- weight: number,
- runTime: number
- ): void {
- this.workersTaskRunTime.set(workerNodeKey, {
- weight,
- runTime
- })
- }
-
- private getWorkerVirtualTaskRunTime (workerNodeKey: number): number {
- return this.requiredStatistics.medRunTime
- ? this.pool.workerNodes[workerNodeKey].tasksUsage.medRunTime
- : this.pool.workerNodes[workerNodeKey].tasksUsage.avgRunTime
+ return true
}
- private computeWorkerWeight (): number {
- let cpusCycleTimeWeight = 0
- for (const cpu of cpus()) {
- // CPU estimated cycle time
- const numberOfDigits = cpu.speed.toString().length - 1
- const cpuCycleTime = 1 / (cpu.speed / Math.pow(10, numberOfDigits))
- cpusCycleTimeWeight += cpuCycleTime * Math.pow(10, numberOfDigits)
+ private weightedRoundRobinNextWorkerNodeKey (): number {
+ const workerVirtualTaskRunTime = this.workerVirtualTaskRunTime
+ const workerWeight =
+ this.opts.weights?.[this.nextWorkerNodeKey] ?? this.defaultWorkerWeight
+ if (workerVirtualTaskRunTime < workerWeight) {
+ this.workerVirtualTaskRunTime =
+ workerVirtualTaskRunTime +
+ this.getWorkerTaskRunTime(this.nextWorkerNodeKey)
+ } else {
+ this.nextWorkerNodeKey =
+ this.nextWorkerNodeKey === this.pool.workerNodes.length - 1
+ ? 0
+ : this.nextWorkerNodeKey + 1
+ this.workerVirtualTaskRunTime = 0
}
- return Math.round(cpusCycleTimeWeight / cpus().length)
+ return this.nextWorkerNodeKey
}
}