import { randomUUID } from 'node:crypto'
import { performance } from 'node:perf_hooks'
-import type { MessageValue, PromiseResponseWrapper } from '../utility-types'
+import { existsSync } from 'node:fs'
+import type {
+ MessageValue,
+ PromiseResponseWrapper,
+ Task
+} from '../utility-types'
import {
DEFAULT_TASK_NAME,
DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
isKillBehavior,
isPlainObject,
median,
- round
+ round,
+ updateMeasurementStatistics
} from '../utils'
import { KillBehaviors } from '../worker/worker-options'
import {
import type {
IWorker,
IWorkerNode,
- MessageHandler,
- Task,
WorkerInfo,
WorkerType,
WorkerUsage
} from './worker'
import {
+ type MeasurementStatisticsRequirements,
Measurements,
WorkerChoiceStrategies,
type WorkerChoiceStrategy,
Response
>
+ /**
+ * Whether the pool is starting or not.
+ */
+ private readonly starting: boolean
/**
* The start timestamp of the pool.
*/
this.setupHook()
- while (this.workerNodes.length < this.numberOfWorkers) {
- this.createAndSetupWorker()
- }
+ this.starting = true
+ this.startPool()
+ this.starting = false
this.startTimestamp = performance.now()
}
private checkFilePath (filePath: string): void {
if (
filePath == null ||
+ typeof filePath !== 'string' ||
(typeof filePath === 'string' && filePath.trim().length === 0)
) {
throw new Error('Please specify a file with a worker implementation')
}
+ if (!existsSync(filePath)) {
+ throw new Error(`Cannot find the worker file '${filePath}'`)
+ }
}
private checkNumberOfWorkers (numberOfWorkers: number): void {
throw new RangeError(
'Cannot instantiate a dynamic pool with a maximum pool size inferior to the minimum pool size'
)
- } else if (min === 0 && max === 0) {
+ } else if (max === 0) {
throw new RangeError(
- 'Cannot instantiate a dynamic pool with a minimum pool size and a maximum pool size equal to zero'
+ 'Cannot instantiate a dynamic pool with a pool size equal to zero'
)
} else if (min === max) {
throw new RangeError(
}
}
+ private startPool (): void {
+ while (
+ this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ !workerNode.info.dynamic ? accumulator + 1 : accumulator,
+ 0
+ ) < this.numberOfWorkers
+ ) {
+ this.createAndSetupWorker()
+ }
+ }
+
/** @inheritDoc */
public get info (): PoolInfo {
return {
),
maxQueuedTasks: this.workerNodes.reduce(
(accumulator, workerNode) =>
- accumulator + workerNode.usage.tasks.maxQueued,
+ accumulator + (workerNode.usage.tasks?.maxQueued ?? 0),
0
),
failedTasks: this.workerNodes.reduce(
}
}
- private get starting (): boolean {
- return (
- this.workerNodes.length < this.minSize ||
- (this.workerNodes.length >= this.minSize &&
- this.workerNodes.some(workerNode => !workerNode.info.ready))
- )
- }
-
private get ready (): boolean {
return (
- this.workerNodes.length >= this.minSize &&
- this.workerNodes.every(workerNode => workerNode.info.ready)
+ this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ !workerNode.info.dynamic && workerNode.info.ready
+ ? accumulator + 1
+ : accumulator,
+ 0
+ ) >= this.minSize
)
}
* @returns The pool utilization.
*/
private get utilization (): number {
- const poolRunTimeCapacity =
+ const poolTimeCapacity =
(performance.now() - this.startTimestamp) * this.maxSize
const totalTasksRunTime = this.workerNodes.reduce(
(accumulator, workerNode) =>
accumulator + (workerNode.usage.waitTime?.aggregate ?? 0),
0
)
- return (totalTasksRunTime + totalTasksWaitTime) / poolRunTimeCapacity
+ return (totalTasksRunTime + totalTasksWaitTime) / poolTimeCapacity
}
/**
?.worker
}
+ /**
+ * Checks if the worker id sent in the received message from a worker is valid.
+ *
+ * @param message - The received message.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker id is invalid.
+ */
private checkMessageWorkerId (message: MessageValue<Response>): void {
if (
message.workerId != null &&
* @param worker - The worker.
* @returns The worker node key if found in the pool worker nodes, `-1` otherwise.
*/
- private getWorkerNodeKey (worker: Worker): number {
+ protected getWorkerNodeKey (worker: Worker): number {
return this.workerNodes.findIndex(
workerNode => workerNode.worker === worker
)
const workerUsage = this.workerNodes[workerNodeKey].usage
++workerUsage.tasks.executing
this.updateWaitTimeWorkerUsage(workerUsage, task)
- const tasksWorkerUsage = this.workerNodes[
- workerNodeKey
- ].getTasksWorkerUsage(task.name as string) as WorkerUsage
- ++tasksWorkerUsage.tasks.executing
- this.updateWaitTimeWorkerUsage(tasksWorkerUsage, task)
+ const taskWorkerUsage = this.workerNodes[workerNodeKey].getTaskWorkerUsage(
+ task.name as string
+ ) as WorkerUsage
+ ++taskWorkerUsage.tasks.executing
+ this.updateWaitTimeWorkerUsage(taskWorkerUsage, task)
}
/**
this.updateTaskStatisticsWorkerUsage(workerUsage, message)
this.updateRunTimeWorkerUsage(workerUsage, message)
this.updateEluWorkerUsage(workerUsage, message)
- const tasksWorkerUsage = this.workerNodes[
- workerNodeKey
- ].getTasksWorkerUsage(message.name as string) as WorkerUsage
- this.updateTaskStatisticsWorkerUsage(tasksWorkerUsage, message)
- this.updateRunTimeWorkerUsage(tasksWorkerUsage, message)
- this.updateEluWorkerUsage(tasksWorkerUsage, message)
+ const taskWorkerUsage = this.workerNodes[workerNodeKey].getTaskWorkerUsage(
+ message.taskPerformance?.name ?? DEFAULT_TASK_NAME
+ ) as WorkerUsage
+ this.updateTaskStatisticsWorkerUsage(taskWorkerUsage, message)
+ this.updateRunTimeWorkerUsage(taskWorkerUsage, message)
+ this.updateEluWorkerUsage(taskWorkerUsage, message)
}
private updateTaskStatisticsWorkerUsage (
workerUsage: WorkerUsage,
message: MessageValue<Response>
): void {
- if (
- this.workerChoiceStrategyContext.getTaskStatisticsRequirements().runTime
- .aggregate
- ) {
- const taskRunTime = message.taskPerformance?.runTime ?? 0
- workerUsage.runTime.aggregate =
- (workerUsage.runTime.aggregate ?? 0) + taskRunTime
- workerUsage.runTime.minimum = Math.min(
- taskRunTime,
- workerUsage.runTime?.minimum ?? Infinity
- )
- workerUsage.runTime.maximum = Math.max(
- taskRunTime,
- workerUsage.runTime?.maximum ?? -Infinity
- )
- if (
- this.workerChoiceStrategyContext.getTaskStatisticsRequirements().runTime
- .average &&
- workerUsage.tasks.executed !== 0
- ) {
- workerUsage.runTime.average =
- workerUsage.runTime.aggregate / workerUsage.tasks.executed
- }
- if (
- this.workerChoiceStrategyContext.getTaskStatisticsRequirements().runTime
- .median &&
- message.taskPerformance?.runTime != null
- ) {
- workerUsage.runTime.history.push(message.taskPerformance.runTime)
- workerUsage.runTime.median = median(workerUsage.runTime.history)
- }
- }
+ updateMeasurementStatistics(
+ workerUsage.runTime,
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().runTime,
+ message.taskPerformance?.runTime ?? 0,
+ workerUsage.tasks.executed
+ )
}
private updateWaitTimeWorkerUsage (
): void {
const timestamp = performance.now()
const taskWaitTime = timestamp - (task.timestamp ?? timestamp)
- if (
- this.workerChoiceStrategyContext.getTaskStatisticsRequirements().waitTime
- .aggregate
- ) {
- workerUsage.waitTime.aggregate =
- (workerUsage.waitTime?.aggregate ?? 0) + taskWaitTime
- workerUsage.waitTime.minimum = Math.min(
- taskWaitTime,
- workerUsage.waitTime?.minimum ?? Infinity
- )
- workerUsage.waitTime.maximum = Math.max(
- taskWaitTime,
- workerUsage.waitTime?.maximum ?? -Infinity
- )
- if (
- this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
- .waitTime.average &&
- workerUsage.tasks.executed !== 0
- ) {
- workerUsage.waitTime.average =
- workerUsage.waitTime.aggregate / workerUsage.tasks.executed
- }
- if (
- this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
- .waitTime.median
- ) {
- workerUsage.waitTime.history.push(taskWaitTime)
- workerUsage.waitTime.median = median(workerUsage.waitTime.history)
- }
- }
+ updateMeasurementStatistics(
+ workerUsage.waitTime,
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().waitTime,
+ taskWaitTime,
+ workerUsage.tasks.executed
+ )
}
private updateEluWorkerUsage (
workerUsage: WorkerUsage,
message: MessageValue<Response>
): void {
- if (
+ const eluTaskStatisticsRequirements: MeasurementStatisticsRequirements =
this.workerChoiceStrategyContext.getTaskStatisticsRequirements().elu
- .aggregate
- ) {
+ updateMeasurementStatistics(
+ workerUsage.elu.active,
+ eluTaskStatisticsRequirements,
+ message.taskPerformance?.elu?.active ?? 0,
+ workerUsage.tasks.executed
+ )
+ updateMeasurementStatistics(
+ workerUsage.elu.idle,
+ eluTaskStatisticsRequirements,
+ message.taskPerformance?.elu?.idle ?? 0,
+ workerUsage.tasks.executed
+ )
+ if (eluTaskStatisticsRequirements.aggregate) {
if (message.taskPerformance?.elu != null) {
- workerUsage.elu.idle.aggregate =
- (workerUsage.elu.idle?.aggregate ?? 0) +
- message.taskPerformance.elu.idle
- workerUsage.elu.active.aggregate =
- (workerUsage.elu.active?.aggregate ?? 0) +
- message.taskPerformance.elu.active
if (workerUsage.elu.utilization != null) {
workerUsage.elu.utilization =
(workerUsage.elu.utilization +
} else {
workerUsage.elu.utilization = message.taskPerformance.elu.utilization
}
- workerUsage.elu.idle.minimum = Math.min(
- message.taskPerformance.elu.idle,
- workerUsage.elu.idle?.minimum ?? Infinity
- )
- workerUsage.elu.idle.maximum = Math.max(
- message.taskPerformance.elu.idle,
- workerUsage.elu.idle?.maximum ?? -Infinity
- )
- workerUsage.elu.active.minimum = Math.min(
- message.taskPerformance.elu.active,
- workerUsage.elu.active?.minimum ?? Infinity
- )
- workerUsage.elu.active.maximum = Math.max(
- message.taskPerformance.elu.active,
- workerUsage.elu.active?.maximum ?? -Infinity
- )
- if (
- this.workerChoiceStrategyContext.getTaskStatisticsRequirements().elu
- .average &&
- workerUsage.tasks.executed !== 0
- ) {
- workerUsage.elu.idle.average =
- workerUsage.elu.idle.aggregate / workerUsage.tasks.executed
- workerUsage.elu.active.average =
- workerUsage.elu.active.aggregate / workerUsage.tasks.executed
- }
- if (
- this.workerChoiceStrategyContext.getTaskStatisticsRequirements().elu
- .median
- ) {
- workerUsage.elu.idle.history.push(message.taskPerformance.elu.idle)
- workerUsage.elu.active.history.push(
- message.taskPerformance.elu.active
- )
- workerUsage.elu.idle.median = median(workerUsage.elu.idle.history)
- workerUsage.elu.active.median = median(workerUsage.elu.active.history)
- }
}
}
}
message: MessageValue<Data>
): void
- /**
- * Registers a listener callback on the given worker.
- *
- * @param worker - The worker which should register a listener.
- * @param listener - The message listener callback.
- */
- private registerWorkerMessageListener<Message extends Data | Response>(
- worker: Worker,
- listener: (message: MessageValue<Message>) => void
- ): void {
- worker.on('message', listener as MessageHandler<Worker>)
- }
-
/**
* Creates a new worker.
*
*/
protected abstract createWorker (): Worker
- /**
- * Function that can be hooked up when a worker has been newly created and moved to the pool worker nodes.
- * Can be overridden.
- *
- * @param worker - The newly created worker.
- */
- protected afterWorkerSetup (worker: Worker): void {
- // Listen to worker messages.
- this.registerWorkerMessageListener(worker, this.workerListener())
- // Send startup message to worker.
- this.sendToWorker(worker, {
- ready: false,
- workerId: this.getWorkerInfo(this.getWorkerNodeKey(worker)).id as number
- })
- // Setup worker task statistics computation.
- this.setWorkerStatistics(worker)
- }
-
/**
* Creates a new worker and sets it up completely in the pool worker nodes.
*
worker.on('message', this.opts.messageHandler ?? EMPTY_FUNCTION)
worker.on('error', this.opts.errorHandler ?? EMPTY_FUNCTION)
worker.on('error', error => {
- if (this.emitter != null) {
- this.emitter.emit(PoolEvents.error, error)
- }
- if (this.opts.enableTasksQueue === true) {
- this.redistributeQueuedTasks(worker)
- }
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ const workerInfo = this.getWorkerInfo(workerNodeKey)
+ workerInfo.ready = false
+ this.workerNodes[workerNodeKey].closeChannel()
+ this.emitter?.emit(PoolEvents.error, error)
if (this.opts.restartWorkerOnError === true && !this.starting) {
- if (this.getWorkerInfo(this.getWorkerNodeKey(worker)).dynamic) {
+ if (workerInfo.dynamic) {
this.createAndSetupDynamicWorker()
} else {
this.createAndSetupWorker()
}
}
+ if (this.opts.enableTasksQueue === true) {
+ this.redistributeQueuedTasks(workerNodeKey)
+ }
})
worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
worker.on('exit', this.opts.exitHandler ?? EMPTY_FUNCTION)
this.removeWorkerNode(worker)
})
- this.pushWorkerNode(worker)
+ this.addWorkerNode(worker)
this.afterWorkerSetup(worker)
return worker
}
- private redistributeQueuedTasks (worker: Worker): void {
- const workerNodeKey = this.getWorkerNodeKey(worker)
- while (this.tasksQueueSize(workerNodeKey) > 0) {
- let targetWorkerNodeKey: number = workerNodeKey
- let minQueuedTasks = Infinity
- for (const [workerNodeId, workerNode] of this.workerNodes.entries()) {
- if (
- workerNodeId !== workerNodeKey &&
- workerNode.usage.tasks.queued === 0
- ) {
- targetWorkerNodeKey = workerNodeId
- break
- }
- if (
- workerNodeId !== workerNodeKey &&
- workerNode.usage.tasks.queued < minQueuedTasks
- ) {
- minQueuedTasks = workerNode.usage.tasks.queued
- targetWorkerNodeKey = workerNodeId
- }
- }
- this.enqueueTask(
- targetWorkerNodeKey,
- this.dequeueTask(workerNodeKey) as Task<Data>
- )
- }
- }
-
/**
* Creates a new dynamic worker and sets it up completely in the pool worker nodes.
*
void (this.destroyWorker(worker) as Promise<void>)
}
})
- const workerInfo = this.getWorkerInfo(this.getWorkerNodeKey(worker))
+ const workerInfo = this.getWorkerInfoByWorker(worker)
workerInfo.dynamic = true
+ if (this.workerChoiceStrategyContext.getStrategyPolicy().useDynamicWorker) {
+ workerInfo.ready = true
+ }
this.sendToWorker(worker, {
- checkAlive: true,
+ checkActive: true,
workerId: workerInfo.id as number
})
return worker
}
+ /**
+ * Registers a listener callback on the given worker.
+ *
+ * @param worker - The worker which should register a listener.
+ * @param listener - The message listener callback.
+ */
+ protected abstract registerWorkerMessageListener<
+ Message extends Data | Response
+ >(worker: Worker, listener: (message: MessageValue<Message>) => void): void
+
+ /**
+ * Function that can be hooked up when a worker has been newly created and moved to the pool worker nodes.
+ * Can be overridden.
+ *
+ * @param worker - The newly created worker.
+ */
+ protected afterWorkerSetup (worker: Worker): void {
+ // Listen to worker messages.
+ this.registerWorkerMessageListener(worker, this.workerListener())
+ // Send the startup message to worker.
+ this.sendStartupMessageToWorker(worker)
+ // Setup worker task statistics computation.
+ this.setWorkerStatistics(worker)
+ }
+
+ /**
+ * Sends the startup message to the given worker.
+ *
+ * @param worker - The worker which should receive the startup message.
+ */
+ protected abstract sendStartupMessageToWorker (worker: Worker): void
+
+ private redistributeQueuedTasks (workerNodeKey: number): void {
+ while (this.tasksQueueSize(workerNodeKey) > 0) {
+ let targetWorkerNodeKey: number = workerNodeKey
+ let minQueuedTasks = Infinity
+ for (const [workerNodeId, workerNode] of this.workerNodes.entries()) {
+ const workerInfo = this.getWorkerInfo(workerNodeId)
+ if (
+ workerNodeId !== workerNodeKey &&
+ workerInfo.ready &&
+ workerNode.usage.tasks.queued === 0
+ ) {
+ targetWorkerNodeKey = workerNodeId
+ break
+ }
+ if (
+ workerNodeId !== workerNodeKey &&
+ workerInfo.ready &&
+ workerNode.usage.tasks.queued < minQueuedTasks
+ ) {
+ minQueuedTasks = workerNode.usage.tasks.queued
+ targetWorkerNodeKey = workerNodeId
+ }
+ }
+ this.enqueueTask(
+ targetWorkerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ }
+ }
+
/**
* This function is the listener registered for each worker message.
*
protected workerListener (): (message: MessageValue<Response>) => void {
return message => {
this.checkMessageWorkerId(message)
- if (message.ready != null && message.workerId != null) {
- // Worker ready message received
- this.handleWorkerReadyMessage(message)
+ if (message.ready != null) {
+ // Worker ready response received
+ this.handleWorkerReadyResponse(message)
} else if (message.id != null) {
// Task execution response received
this.handleTaskExecutionResponse(message)
}
}
- private handleWorkerReadyMessage (message: MessageValue<Response>): void {
- const worker = this.getWorkerById(message.workerId)
- this.getWorkerInfo(this.getWorkerNodeKey(worker as Worker)).ready =
- message.ready as boolean
+ private handleWorkerReadyResponse (message: MessageValue<Response>): void {
+ this.getWorkerInfoByWorker(
+ this.getWorkerById(message.workerId) as Worker
+ ).ready = message.ready as boolean
if (this.emitter != null && this.ready) {
this.emitter.emit(PoolEvents.ready, this.info)
}
const promiseResponse = this.promiseResponseMap.get(message.id as string)
if (promiseResponse != null) {
if (message.taskError != null) {
- if (this.emitter != null) {
- this.emitter.emit(PoolEvents.taskError, message.taskError)
- }
+ this.emitter?.emit(PoolEvents.taskError, message.taskError)
promiseResponse.reject(message.taskError.message)
} else {
promiseResponse.resolve(message.data as Response)
}
/**
- * Gets the worker information.
+ * Gets the worker information from the given worker node key.
*
* @param workerNodeKey - The worker node key.
+ * @returns The worker information.
*/
private getWorkerInfo (workerNodeKey: number): WorkerInfo {
return this.workerNodes[workerNodeKey].info
}
/**
- * Pushes the given worker in the pool worker nodes.
+ * Gets the worker information from the given worker.
+ *
+ * @param worker - The worker.
+ * @returns The worker information.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker is not found.
+ */
+ protected getWorkerInfoByWorker (worker: Worker): WorkerInfo {
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ if (workerNodeKey === -1) {
+ throw new Error('Worker not found')
+ }
+ return this.workerNodes[workerNodeKey].info
+ }
+
+ /**
+ * Adds the given worker in the pool worker nodes.
*
* @param worker - The worker.
* @returns The worker nodes length.
*/
- private pushWorkerNode (worker: Worker): number {
- return this.workerNodes.push(new WorkerNode(worker, this.worker))
+ private addWorkerNode (worker: Worker): number {
+ const workerNode = new WorkerNode<Worker, Data>(worker, this.worker)
+ // Flag the worker node as ready at pool startup.
+ if (this.starting) {
+ workerNode.info.ready = true
+ }
+ return this.workerNodes.push(workerNode)
}
/**
}
}
+ /**
+ * Executes the given task on the given worker.
+ *
+ * @param worker - The worker.
+ * @param task - The task to execute.
+ */
private executeTask (workerNodeKey: number, task: Task<Data>): void {
this.beforeTaskExecutionHook(workerNodeKey, task)
this.sendToWorker(this.workerNodes[workerNodeKey].worker, task)
elu: this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
.elu.aggregate
},
- workerId: this.getWorkerInfo(this.getWorkerNodeKey(worker)).id as number
+ workerId: this.getWorkerInfoByWorker(worker).id as number
})
}
}