import { randomUUID } from 'node:crypto'
import { performance } from 'node:perf_hooks'
import { existsSync } from 'node:fs'
+import { type TransferListItem } from 'node:worker_threads'
import type {
MessageValue,
PromiseResponseWrapper,
DEFAULT_TASK_NAME,
DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
EMPTY_FUNCTION,
+ average,
isKillBehavior,
isPlainObject,
+ max,
median,
+ min,
round,
updateMeasurementStatistics
} from '../utils'
public readonly emitter?: PoolEmitter
/**
- * The execution response promise map.
+ * The task execution response promise map.
*
* - `key`: The message id of each submitted task.
* - `value`: An object that contains the worker, the execution response promise resolve and reject callbacks.
*
* When we receive a message from the worker, we get a map entry with the promise resolve/reject bound to the message id.
*/
- protected promiseResponseMap: Map<
- string,
- PromiseResponseWrapper<Worker, Response>
- > = new Map<string, PromiseResponseWrapper<Worker, Response>>()
+ protected promiseResponseMap: Map<string, PromiseResponseWrapper<Response>> =
+ new Map<string, PromiseResponseWrapper<Response>>()
/**
* Worker choice strategy context referencing a worker choice algorithm implementation.
Response
>
+ /**
+ * Dynamic pool maximum size property placeholder.
+ */
+ protected readonly max?: number
+
/**
* Whether the pool is starting or not.
*/
private readonly starting: boolean
+ /**
+ * Whether the pool is started or not.
+ */
+ private started: boolean
/**
* The start timestamp of the pool.
*/
protected readonly opts: PoolOptions<Worker>
) {
if (!this.isMain()) {
- throw new Error('Cannot start a pool from a worker!')
+ throw new Error(
+ 'Cannot start a pool from a worker with the same type as the pool'
+ )
}
this.checkNumberOfWorkers(this.numberOfWorkers)
this.checkFilePath(this.filePath)
this.chooseWorkerNode = this.chooseWorkerNode.bind(this)
this.executeTask = this.executeTask.bind(this)
this.enqueueTask = this.enqueueTask.bind(this)
- this.checkAndEmitEvents = this.checkAndEmitEvents.bind(this)
if (this.opts.enableEvents === true) {
this.emitter = new PoolEmitter()
this.starting = true
this.startPool()
this.starting = false
+ this.started = true
this.startTimestamp = performance.now()
}
protected checkDynamicPoolSize (min: number, max: number): void {
if (this.type === PoolTypes.dynamic) {
- if (min > max) {
+ if (max == null) {
+ throw new TypeError(
+ 'Cannot instantiate a dynamic pool without specifying the maximum pool size'
+ )
+ } else if (!Number.isSafeInteger(max)) {
+ throw new TypeError(
+ 'Cannot instantiate a dynamic pool with a non safe integer maximum pool size'
+ )
+ } else if (min > max) {
throw new RangeError(
'Cannot instantiate a dynamic pool with a maximum pool size inferior to the minimum pool size'
)
} else if (max === 0) {
throw new RangeError(
- 'Cannot instantiate a dynamic pool with a pool size equal to zero'
+ 'Cannot instantiate a dynamic pool with a maximum pool size equal to zero'
)
} else if (min === max) {
throw new RangeError(
this.opts.workerChoiceStrategy =
opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
this.checkValidWorkerChoiceStrategy(this.opts.workerChoiceStrategy)
- this.opts.workerChoiceStrategyOptions =
- opts.workerChoiceStrategyOptions ??
- DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
+ this.opts.workerChoiceStrategyOptions = {
+ ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+ ...opts.workerChoiceStrategyOptions
+ }
this.checkValidWorkerChoiceStrategyOptions(
this.opts.workerChoiceStrategyOptions
)
'Invalid worker choice strategy options: must be a plain object'
)
}
+ if (
+ workerChoiceStrategyOptions.retries != null &&
+ !Number.isSafeInteger(workerChoiceStrategyOptions.retries)
+ ) {
+ throw new TypeError(
+ 'Invalid worker choice strategy options: retries must be an integer'
+ )
+ }
+ if (
+ workerChoiceStrategyOptions.retries != null &&
+ workerChoiceStrategyOptions.retries < 0
+ ) {
+ throw new RangeError(
+ `Invalid worker choice strategy options: retries '${workerChoiceStrategyOptions.retries}' must be greater or equal than zero`
+ )
+ }
if (
workerChoiceStrategyOptions.weights != null &&
Object.keys(workerChoiceStrategyOptions.weights).length !== this.maxSize
}
if (
tasksQueueOptions?.concurrency != null &&
- !Number.isSafeInteger(tasksQueueOptions.concurrency)
+ !Number.isSafeInteger(tasksQueueOptions?.concurrency)
) {
throw new TypeError(
- 'Invalid worker tasks concurrency: must be an integer'
+ 'Invalid worker node tasks concurrency: must be an integer'
)
}
if (
tasksQueueOptions?.concurrency != null &&
- tasksQueueOptions.concurrency <= 0
+ tasksQueueOptions?.concurrency <= 0
) {
+ throw new RangeError(
+ `Invalid worker node tasks concurrency: ${tasksQueueOptions?.concurrency} is a negative integer or zero`
+ )
+ }
+ if (tasksQueueOptions?.queueMaxSize != null) {
throw new Error(
- `Invalid worker tasks concurrency '${tasksQueueOptions.concurrency}'`
+ 'Invalid tasks queue options: queueMaxSize is deprecated, please use size instead'
+ )
+ }
+ if (
+ tasksQueueOptions?.size != null &&
+ !Number.isSafeInteger(tasksQueueOptions?.size)
+ ) {
+ throw new TypeError(
+ 'Invalid worker node tasks queue size: must be an integer'
+ )
+ }
+ if (tasksQueueOptions?.size != null && tasksQueueOptions?.size <= 0) {
+ throw new RangeError(
+ `Invalid worker node tasks queue size: ${tasksQueueOptions?.size} is a negative integer or zero`
)
}
}
0
) < this.numberOfWorkers
) {
- this.createAndSetupWorker()
+ this.createAndSetupWorkerNode()
}
}
accumulator + workerNode.usage.tasks.executing,
0
),
- queuedTasks: this.workerNodes.reduce(
- (accumulator, workerNode) =>
- accumulator + workerNode.usage.tasks.queued,
- 0
- ),
- maxQueuedTasks: this.workerNodes.reduce(
- (accumulator, workerNode) =>
- accumulator + (workerNode.usage.tasks?.maxQueued ?? 0),
- 0
- ),
+ ...(this.opts.enableTasksQueue === true && {
+ queuedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.queued,
+ 0
+ )
+ }),
+ ...(this.opts.enableTasksQueue === true && {
+ maxQueuedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + (workerNode.usage.tasks?.maxQueued ?? 0),
+ 0
+ )
+ }),
+ ...(this.opts.enableTasksQueue === true && {
+ backPressure: this.hasBackPressure()
+ }),
+ ...(this.opts.enableTasksQueue === true && {
+ stolenTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.stolen,
+ 0
+ )
+ }),
failedTasks: this.workerNodes.reduce(
(accumulator, workerNode) =>
accumulator + workerNode.usage.tasks.failed,
.runTime.aggregate && {
runTime: {
minimum: round(
- Math.min(
+ min(
...this.workerNodes.map(
workerNode => workerNode.usage.runTime?.minimum ?? Infinity
)
)
),
maximum: round(
- Math.max(
+ max(
...this.workerNodes.map(
workerNode => workerNode.usage.runTime?.maximum ?? -Infinity
)
)
),
- average: round(
- this.workerNodes.reduce(
- (accumulator, workerNode) =>
- accumulator + (workerNode.usage.runTime?.aggregate ?? 0),
- 0
- ) /
- this.workerNodes.reduce(
- (accumulator, workerNode) =>
- accumulator + (workerNode.usage.tasks?.executed ?? 0),
- 0
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.average && {
+ average: round(
+ average(
+ this.workerNodes.reduce<number[]>(
+ (accumulator, workerNode) =>
+ accumulator.concat(workerNode.usage.runTime.history),
+ []
+ )
)
- ),
+ )
+ }),
...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
.runTime.median && {
median: round(
median(
- this.workerNodes.map(
- workerNode => workerNode.usage.runTime?.median ?? 0
+ this.workerNodes.reduce<number[]>(
+ (accumulator, workerNode) =>
+ accumulator.concat(workerNode.usage.runTime.history),
+ []
)
)
)
.waitTime.aggregate && {
waitTime: {
minimum: round(
- Math.min(
+ min(
...this.workerNodes.map(
workerNode => workerNode.usage.waitTime?.minimum ?? Infinity
)
)
),
maximum: round(
- Math.max(
+ max(
...this.workerNodes.map(
workerNode => workerNode.usage.waitTime?.maximum ?? -Infinity
)
)
),
- average: round(
- this.workerNodes.reduce(
- (accumulator, workerNode) =>
- accumulator + (workerNode.usage.waitTime?.aggregate ?? 0),
- 0
- ) /
- this.workerNodes.reduce(
- (accumulator, workerNode) =>
- accumulator + (workerNode.usage.tasks?.executed ?? 0),
- 0
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.average && {
+ average: round(
+ average(
+ this.workerNodes.reduce<number[]>(
+ (accumulator, workerNode) =>
+ accumulator.concat(workerNode.usage.waitTime.history),
+ []
+ )
)
- ),
+ )
+ }),
...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
.waitTime.median && {
median: round(
median(
- this.workerNodes.map(
- workerNode => workerNode.usage.waitTime?.median ?? 0
+ this.workerNodes.reduce<number[]>(
+ (accumulator, workerNode) =>
+ accumulator.concat(workerNode.usage.waitTime.history),
+ []
)
)
)
}
}
+ /**
+ * The pool readiness boolean status.
+ */
private get ready (): boolean {
return (
this.workerNodes.reduce(
}
/**
- * Gets the approximate pool utilization.
+ * The approximate pool utilization.
*
* @returns The pool utilization.
*/
}
/**
- * Pool type.
+ * The pool type.
*
* If it is `'dynamic'`, it provides the `max` property.
*/
protected abstract get type (): PoolType
/**
- * Gets the worker type.
+ * The worker type.
*/
protected abstract get worker (): WorkerType
/**
- * Pool minimum size.
- */
- protected abstract get minSize (): number
-
- /**
- * Pool maximum size.
+ * The pool minimum size.
*/
- protected abstract get maxSize (): number
+ protected get minSize (): number {
+ return this.numberOfWorkers
+ }
/**
- * Get the worker given its id.
- *
- * @param workerId - The worker id.
- * @returns The worker if found in the pool worker nodes, `undefined` otherwise.
+ * The pool maximum size.
*/
- private getWorkerById (workerId: number): Worker | undefined {
- return this.workerNodes.find(workerNode => workerNode.info.id === workerId)
- ?.worker
+ protected get maxSize (): number {
+ return this.max ?? this.numberOfWorkers
}
/**
* @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker id is invalid.
*/
private checkMessageWorkerId (message: MessageValue<Response>): void {
- if (
+ if (message.workerId == null) {
+ throw new Error('Worker message received without worker id')
+ } else if (
message.workerId != null &&
- this.getWorkerById(message.workerId) == null
+ this.getWorkerNodeKeyByWorkerId(message.workerId) === -1
) {
throw new Error(
`Worker message received from unknown worker '${message.workerId}'`
* @param worker - The worker.
* @returns The worker node key if found in the pool worker nodes, `-1` otherwise.
*/
- protected getWorkerNodeKey (worker: Worker): number {
+ private getWorkerNodeKeyByWorker (worker: Worker): number {
return this.workerNodes.findIndex(
workerNode => workerNode.worker === worker
)
}
+ /**
+ * Gets the worker node key given its worker id.
+ *
+ * @param workerId - The worker id.
+ * @returns The worker node key if the worker id is found in the pool worker nodes, `-1` otherwise.
+ */
+ private getWorkerNodeKeyByWorkerId (workerId: number): number {
+ return this.workerNodes.findIndex(
+ workerNode => workerNode.info.id === workerId
+ )
+ }
+
/** @inheritDoc */
public setWorkerChoiceStrategy (
workerChoiceStrategy: WorkerChoiceStrategy,
if (workerChoiceStrategyOptions != null) {
this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
}
- for (const workerNode of this.workerNodes) {
+ for (const [workerNodeKey, workerNode] of this.workerNodes.entries()) {
workerNode.resetUsage()
- this.setWorkerStatistics(workerNode.worker)
+ this.sendStatisticsMessageToWorker(workerNodeKey)
}
}
workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
): void {
this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
- this.opts.workerChoiceStrategyOptions = workerChoiceStrategyOptions
+ this.opts.workerChoiceStrategyOptions = {
+ ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+ ...workerChoiceStrategyOptions
+ }
this.workerChoiceStrategyContext.setOptions(
this.opts.workerChoiceStrategyOptions
)
this.checkValidTasksQueueOptions(tasksQueueOptions)
this.opts.tasksQueueOptions =
this.buildTasksQueueOptions(tasksQueueOptions)
+ this.setTasksQueueSize(this.opts.tasksQueueOptions.size as number)
} else if (this.opts.tasksQueueOptions != null) {
delete this.opts.tasksQueueOptions
}
}
+ private setTasksQueueSize (size: number): void {
+ for (const workerNode of this.workerNodes) {
+ workerNode.tasksQueueBackPressureSize = size
+ }
+ }
+
private buildTasksQueueOptions (
tasksQueueOptions: TasksQueueOptions
): TasksQueueOptions {
return {
- concurrency: tasksQueueOptions?.concurrency ?? 1
+ ...{
+ size: Math.pow(this.maxSize, 2),
+ concurrency: 1
+ },
+ ...tasksQueueOptions
}
}
protected abstract get busy (): boolean
/**
- * Whether worker nodes are executing at least one task.
+ * Whether worker nodes are executing concurrently their tasks quota or not.
*
* @returns Worker nodes busyness boolean status.
*/
protected internalBusy (): boolean {
+ if (this.opts.enableTasksQueue === true) {
+ return (
+ this.workerNodes.findIndex(
+ workerNode =>
+ workerNode.info.ready &&
+ workerNode.usage.tasks.executing <
+ (this.opts.tasksQueueOptions?.concurrency as number)
+ ) === -1
+ )
+ } else {
+ return (
+ this.workerNodes.findIndex(
+ workerNode =>
+ workerNode.info.ready && workerNode.usage.tasks.executing === 0
+ ) === -1
+ )
+ }
+ }
+
+ /** @inheritDoc */
+ public listTaskFunctions (): string[] {
+ for (const workerNode of this.workerNodes) {
+ if (
+ Array.isArray(workerNode.info.taskFunctions) &&
+ workerNode.info.taskFunctions.length > 0
+ ) {
+ return workerNode.info.taskFunctions
+ }
+ }
+ return []
+ }
+
+ private shallExecuteTask (workerNodeKey: number): boolean {
return (
- this.workerNodes.findIndex(workerNode => {
- return workerNode.usage.tasks.executing === 0
- }) === -1
+ this.tasksQueueSize(workerNodeKey) === 0 &&
+ this.workerNodes[workerNodeKey].usage.tasks.executing <
+ (this.opts.tasksQueueOptions?.concurrency as number)
)
}
/** @inheritDoc */
- public async execute (data?: Data, name?: string): Promise<Response> {
- const timestamp = performance.now()
- const workerNodeKey = this.chooseWorkerNode()
- const submittedTask: Task<Data> = {
- name: name ?? DEFAULT_TASK_NAME,
- // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
- data: data ?? ({} as Data),
- timestamp,
- workerId: this.getWorkerInfo(workerNodeKey).id as number,
- id: randomUUID()
- }
- const res = new Promise<Response>((resolve, reject) => {
- this.promiseResponseMap.set(submittedTask.id as string, {
+ public async execute (
+ data?: Data,
+ name?: string,
+ transferList?: TransferListItem[]
+ ): Promise<Response> {
+ return await new Promise<Response>((resolve, reject) => {
+ if (!this.started) {
+ reject(new Error('Cannot execute a task on destroyed pool'))
+ return
+ }
+ if (name != null && typeof name !== 'string') {
+ reject(new TypeError('name argument must be a string'))
+ return
+ }
+ if (
+ name != null &&
+ typeof name === 'string' &&
+ name.trim().length === 0
+ ) {
+ reject(new TypeError('name argument must not be an empty string'))
+ return
+ }
+ if (transferList != null && !Array.isArray(transferList)) {
+ reject(new TypeError('transferList argument must be an array'))
+ return
+ }
+ const timestamp = performance.now()
+ const workerNodeKey = this.chooseWorkerNode()
+ const task: Task<Data> = {
+ name: name ?? DEFAULT_TASK_NAME,
+ // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+ data: data ?? ({} as Data),
+ transferList,
+ timestamp,
+ workerId: this.getWorkerInfo(workerNodeKey).id as number,
+ taskId: randomUUID()
+ }
+ this.promiseResponseMap.set(task.taskId as string, {
resolve,
reject,
- worker: this.workerNodes[workerNodeKey].worker
+ workerNodeKey
})
+ if (
+ this.opts.enableTasksQueue === false ||
+ (this.opts.enableTasksQueue === true &&
+ this.shallExecuteTask(workerNodeKey))
+ ) {
+ this.executeTask(workerNodeKey, task)
+ } else {
+ this.enqueueTask(workerNodeKey, task)
+ }
})
- if (
- this.opts.enableTasksQueue === true &&
- (this.busy ||
- this.workerNodes[workerNodeKey].usage.tasks.executing >=
- ((this.opts.tasksQueueOptions as TasksQueueOptions)
- .concurrency as number))
- ) {
- this.enqueueTask(workerNodeKey, submittedTask)
- } else {
- this.executeTask(workerNodeKey, submittedTask)
- }
- this.checkAndEmitEvents()
- // eslint-disable-next-line @typescript-eslint/return-await
- return res
}
/** @inheritDoc */
public async destroy (): Promise<void> {
await Promise.all(
- this.workerNodes.map(async (workerNode, workerNodeKey) => {
- this.flushTasksQueue(workerNodeKey)
- // FIXME: wait for tasks to be finished
- const workerExitPromise = new Promise<void>(resolve => {
- workerNode.worker.on('exit', () => {
- resolve()
- })
- })
- await this.destroyWorker(workerNode.worker)
- await workerExitPromise
+ this.workerNodes.map(async (_, workerNodeKey) => {
+ await this.destroyWorkerNode(workerNodeKey)
})
)
+ this.emitter?.emit(PoolEvents.destroy, this.info)
+ this.started = false
+ }
+
+ protected async sendKillMessageToWorker (
+ workerNodeKey: number,
+ workerId: number
+ ): Promise<void> {
+ await new Promise<void>((resolve, reject) => {
+ this.registerWorkerMessageListener(workerNodeKey, message => {
+ if (message.kill === 'success') {
+ resolve()
+ } else if (message.kill === 'failure') {
+ reject(new Error(`Worker ${workerId} kill message handling failed`))
+ }
+ })
+ this.sendToWorker(workerNodeKey, { kill: true, workerId })
+ })
}
/**
- * Terminates the given worker.
+ * Terminates the worker node given its worker node key.
*
- * @param worker - A worker within `workerNodes`.
+ * @param workerNodeKey - The worker node key.
*/
- protected abstract destroyWorker (worker: Worker): void | Promise<void>
+ protected abstract destroyWorkerNode (workerNodeKey: number): Promise<void>
/**
* Setup hook to execute code before worker nodes are created in the abstract constructor.
* @virtual
*/
protected setupHook (): void {
- // Intentionally empty
+ /* Intentionally empty */
}
/**
workerNodeKey: number,
task: Task<Data>
): void {
- const workerUsage = this.workerNodes[workerNodeKey].usage
- ++workerUsage.tasks.executing
- this.updateWaitTimeWorkerUsage(workerUsage, task)
- const taskWorkerUsage = this.workerNodes[workerNodeKey].getTaskWorkerUsage(
- task.name as string
- ) as WorkerUsage
- ++taskWorkerUsage.tasks.executing
- this.updateWaitTimeWorkerUsage(taskWorkerUsage, task)
+ if (this.workerNodes[workerNodeKey]?.usage != null) {
+ const workerUsage = this.workerNodes[workerNodeKey].usage
+ ++workerUsage.tasks.executing
+ this.updateWaitTimeWorkerUsage(workerUsage, task)
+ }
+ if (
+ this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey) &&
+ this.workerNodes[workerNodeKey].getTaskFunctionWorkerUsage(
+ task.name as string
+ ) != null
+ ) {
+ const taskFunctionWorkerUsage = this.workerNodes[
+ workerNodeKey
+ ].getTaskFunctionWorkerUsage(task.name as string) as WorkerUsage
+ ++taskFunctionWorkerUsage.tasks.executing
+ this.updateWaitTimeWorkerUsage(taskFunctionWorkerUsage, task)
+ }
}
/**
* Hook executed after the worker task execution.
* Can be overridden.
*
- * @param worker - The worker.
+ * @param workerNodeKey - The worker node key.
* @param message - The received message.
*/
protected afterTaskExecutionHook (
- worker: Worker,
+ workerNodeKey: number,
message: MessageValue<Response>
): void {
- const workerNodeKey = this.getWorkerNodeKey(worker)
- const workerUsage = this.workerNodes[workerNodeKey].usage
- this.updateTaskStatisticsWorkerUsage(workerUsage, message)
- this.updateRunTimeWorkerUsage(workerUsage, message)
- this.updateEluWorkerUsage(workerUsage, 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)
+ if (this.workerNodes[workerNodeKey]?.usage != null) {
+ const workerUsage = this.workerNodes[workerNodeKey].usage
+ this.updateTaskStatisticsWorkerUsage(workerUsage, message)
+ this.updateRunTimeWorkerUsage(workerUsage, message)
+ this.updateEluWorkerUsage(workerUsage, message)
+ }
+ if (
+ this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey) &&
+ this.workerNodes[workerNodeKey].getTaskFunctionWorkerUsage(
+ message.taskPerformance?.name as string
+ ) != null
+ ) {
+ const taskFunctionWorkerUsage = this.workerNodes[
+ workerNodeKey
+ ].getTaskFunctionWorkerUsage(
+ message.taskPerformance?.name as string
+ ) as WorkerUsage
+ this.updateTaskStatisticsWorkerUsage(taskFunctionWorkerUsage, message)
+ this.updateRunTimeWorkerUsage(taskFunctionWorkerUsage, message)
+ this.updateEluWorkerUsage(taskFunctionWorkerUsage, message)
+ }
+ }
+
+ /**
+ * Whether the worker node shall update its task function worker usage or not.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @returns `true` if the worker node shall update its task function worker usage, `false` otherwise.
+ */
+ private shallUpdateTaskFunctionWorkerUsage (workerNodeKey: number): boolean {
+ const workerInfo = this.getWorkerInfo(workerNodeKey)
+ return (
+ workerInfo != null &&
+ Array.isArray(workerInfo.taskFunctions) &&
+ workerInfo.taskFunctions.length > 2
+ )
}
private updateTaskStatisticsWorkerUsage (
message: MessageValue<Response>
): void {
const workerTaskStatistics = workerUsage.tasks
- --workerTaskStatistics.executing
+ if (
+ workerTaskStatistics.executing != null &&
+ workerTaskStatistics.executing > 0
+ ) {
+ --workerTaskStatistics.executing
+ }
if (message.taskError == null) {
++workerTaskStatistics.executed
} else {
workerUsage: WorkerUsage,
message: MessageValue<Response>
): void {
+ if (message.taskError != null) {
+ return
+ }
updateMeasurementStatistics(
workerUsage.runTime,
this.workerChoiceStrategyContext.getTaskStatisticsRequirements().runTime,
- message.taskPerformance?.runTime ?? 0,
- workerUsage.tasks.executed
+ message.taskPerformance?.runTime ?? 0
)
}
updateMeasurementStatistics(
workerUsage.waitTime,
this.workerChoiceStrategyContext.getTaskStatisticsRequirements().waitTime,
- taskWaitTime,
- workerUsage.tasks.executed
+ taskWaitTime
)
}
workerUsage: WorkerUsage,
message: MessageValue<Response>
): void {
+ if (message.taskError != null) {
+ return
+ }
const eluTaskStatisticsRequirements: MeasurementStatisticsRequirements =
this.workerChoiceStrategyContext.getTaskStatisticsRequirements().elu
updateMeasurementStatistics(
workerUsage.elu.active,
eluTaskStatisticsRequirements,
- message.taskPerformance?.elu?.active ?? 0,
- workerUsage.tasks.executed
+ message.taskPerformance?.elu?.active ?? 0
)
updateMeasurementStatistics(
workerUsage.elu.idle,
eluTaskStatisticsRequirements,
- message.taskPerformance?.elu?.idle ?? 0,
- workerUsage.tasks.executed
+ message.taskPerformance?.elu?.idle ?? 0
)
if (eluTaskStatisticsRequirements.aggregate) {
if (message.taskPerformance?.elu != null) {
*
* The default worker choice strategy uses a round robin algorithm to distribute the tasks.
*
- * @returns The worker node key
+ * @returns The chosen worker node key
*/
private chooseWorkerNode (): number {
if (this.shallCreateDynamicWorker()) {
- const worker = this.createAndSetupDynamicWorker()
+ const workerNodeKey = this.createAndSetupDynamicWorkerNode()
if (
- this.workerChoiceStrategyContext.getStrategyPolicy().useDynamicWorker
+ this.workerChoiceStrategyContext.getStrategyPolicy().dynamicWorkerUsage
) {
- return this.getWorkerNodeKey(worker)
+ return workerNodeKey
}
}
return this.workerChoiceStrategyContext.execute()
}
/**
- * Sends a message to the given worker.
+ * Sends a message to worker given its worker node key.
*
- * @param worker - The worker which should receive the message.
+ * @param workerNodeKey - The worker node key.
* @param message - The message.
+ * @param transferList - The optional array of transferable objects.
*/
protected abstract sendToWorker (
- worker: Worker,
- message: MessageValue<Data>
+ workerNodeKey: number,
+ message: MessageValue<Data>,
+ transferList?: TransferListItem[]
): void
/**
protected abstract createWorker (): Worker
/**
- * Creates a new worker and sets it up completely in the pool worker nodes.
+ * Creates a new, completely set up worker node.
*
- * @returns New, completely set up worker.
+ * @returns New, completely set up worker node key.
*/
- protected createAndSetupWorker (): Worker {
+ protected createAndSetupWorkerNode (): number {
const worker = this.createWorker()
+ worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
worker.on('message', this.opts.messageHandler ?? EMPTY_FUNCTION)
worker.on('error', this.opts.errorHandler ?? EMPTY_FUNCTION)
worker.on('error', error => {
- const workerNodeKey = this.getWorkerNodeKey(worker)
+ const workerNodeKey = this.getWorkerNodeKeyByWorker(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.opts.restartWorkerOnError === true &&
+ this.started &&
+ !this.starting
+ ) {
if (workerInfo.dynamic) {
- this.createAndSetupDynamicWorker()
+ this.createAndSetupDynamicWorkerNode()
} else {
- this.createAndSetupWorker()
+ this.createAndSetupWorkerNode()
}
}
if (this.opts.enableTasksQueue === true) {
this.redistributeQueuedTasks(workerNodeKey)
}
})
- worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
worker.on('exit', this.opts.exitHandler ?? EMPTY_FUNCTION)
worker.once('exit', () => {
- this.workerNodes[this.getWorkerNodeKey(worker)].closeChannel()
this.removeWorkerNode(worker)
})
- this.addWorkerNode(worker)
+ const workerNodeKey = this.addWorkerNode(worker)
- this.afterWorkerSetup(worker)
+ this.afterWorkerNodeSetup(workerNodeKey)
- return worker
+ return workerNodeKey
}
/**
- * Creates a new dynamic worker and sets it up completely in the pool worker nodes.
+ * Creates a new, completely set up dynamic worker node.
*
- * @returns New, completely set up dynamic worker.
+ * @returns New, completely set up dynamic worker node key.
*/
- protected createAndSetupDynamicWorker (): Worker {
- const worker = this.createAndSetupWorker()
- this.registerWorkerMessageListener(worker, message => {
- const workerNodeKey = this.getWorkerNodeKey(worker)
+ protected createAndSetupDynamicWorkerNode (): number {
+ const workerNodeKey = this.createAndSetupWorkerNode()
+ this.registerWorkerMessageListener(workerNodeKey, message => {
+ const localWorkerNodeKey = this.getWorkerNodeKeyByWorkerId(
+ message.workerId
+ )
+ const workerUsage = this.workerNodes[localWorkerNodeKey].usage
+ // Kill message received from worker
if (
isKillBehavior(KillBehaviors.HARD, message.kill) ||
- (message.kill != null &&
+ (isKillBehavior(KillBehaviors.SOFT, message.kill) &&
((this.opts.enableTasksQueue === false &&
- this.workerNodes[workerNodeKey].usage.tasks.executing === 0) ||
+ workerUsage.tasks.executing === 0) ||
(this.opts.enableTasksQueue === true &&
- this.workerNodes[workerNodeKey].usage.tasks.executing === 0 &&
- this.tasksQueueSize(workerNodeKey) === 0)))
+ workerUsage.tasks.executing === 0 &&
+ this.tasksQueueSize(localWorkerNodeKey) === 0)))
) {
- // Kill message received from the worker: no new tasks are submitted to that worker for a while ( > maxInactiveTime)
- void (this.destroyWorker(worker) as Promise<void>)
+ this.destroyWorkerNode(localWorkerNodeKey).catch(error => {
+ this.emitter?.emit(PoolEvents.error, error)
+ })
}
})
- const workerInfo = this.getWorkerInfoByWorker(worker)
- workerInfo.dynamic = true
- if (this.workerChoiceStrategyContext.getStrategyPolicy().useDynamicWorker) {
- workerInfo.ready = true
- }
- this.sendToWorker(worker, {
+ const workerInfo = this.getWorkerInfo(workerNodeKey)
+ this.sendToWorker(workerNodeKey, {
checkActive: true,
workerId: workerInfo.id as number
})
- return worker
+ workerInfo.dynamic = true
+ if (
+ this.workerChoiceStrategyContext.getStrategyPolicy().dynamicWorkerReady ||
+ this.workerChoiceStrategyContext.getStrategyPolicy().dynamicWorkerUsage
+ ) {
+ workerInfo.ready = true
+ }
+ this.checkAndEmitDynamicWorkerCreationEvents()
+ return workerNodeKey
}
/**
- * Registers a listener callback on the given worker.
+ * Registers a listener callback on the worker given its worker node key.
*
- * @param worker - The worker which should register a listener.
+ * @param workerNodeKey - The worker node key.
* @param listener - The message listener callback.
*/
protected abstract registerWorkerMessageListener<
Message extends Data | Response
- >(worker: Worker, listener: (message: MessageValue<Message>) => void): void
+ >(
+ workerNodeKey: number,
+ 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.
+ * Method hooked up after a worker node has been newly created.
* Can be overridden.
*
- * @param worker - The newly created worker.
+ * @param workerNodeKey - The newly created worker node key.
*/
- protected afterWorkerSetup (worker: Worker): void {
+ protected afterWorkerNodeSetup (workerNodeKey: number): void {
// Listen to worker messages.
- this.registerWorkerMessageListener(worker, this.workerListener())
+ this.registerWorkerMessageListener(workerNodeKey, this.workerListener())
// Send the startup message to worker.
- this.sendStartupMessageToWorker(worker)
- // Setup worker task statistics computation.
- this.setWorkerStatistics(worker)
+ this.sendStartupMessageToWorker(workerNodeKey)
+ // Send the statistics message to worker.
+ this.sendStatisticsMessageToWorker(workerNodeKey)
+ if (this.opts.enableTasksQueue === true) {
+ this.workerNodes[workerNodeKey].onEmptyQueue =
+ this.taskStealingOnEmptyQueue.bind(this)
+ this.workerNodes[workerNodeKey].onBackPressure =
+ this.tasksStealingOnBackPressure.bind(this)
+ }
}
/**
- * Sends the startup message to the given worker.
+ * Sends the startup message to worker given its worker node key.
*
- * @param worker - The worker which should receive the startup message.
+ * @param workerNodeKey - The worker node key.
+ */
+ protected abstract sendStartupMessageToWorker (workerNodeKey: number): void
+
+ /**
+ * Sends the statistics message to worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
*/
- protected abstract sendStartupMessageToWorker (worker: Worker): void
+ private sendStatisticsMessageToWorker (workerNodeKey: number): void {
+ this.sendToWorker(workerNodeKey, {
+ statistics: {
+ runTime:
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.aggregate,
+ elu: this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .elu.aggregate
+ },
+ workerId: this.getWorkerInfo(workerNodeKey).id as number
+ })
+ }
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
+ const destinationWorkerNodeKey = this.workerNodes.reduce(
+ (minWorkerNodeKey, workerNode, workerNodeKey, workerNodes) => {
+ return workerNode.info.ready &&
+ workerNode.usage.tasks.queued <
+ workerNodes[minWorkerNodeKey].usage.tasks.queued
+ ? workerNodeKey
+ : minWorkerNodeKey
+ },
+ 0
+ )
+ const destinationWorkerNode = this.workerNodes[destinationWorkerNodeKey]
+ const task = {
+ ...(this.dequeueTask(workerNodeKey) as Task<Data>),
+ workerId: destinationWorkerNode.info.id as number
+ }
+ if (this.shallExecuteTask(destinationWorkerNodeKey)) {
+ this.executeTask(destinationWorkerNodeKey, task)
+ } else {
+ this.enqueueTask(destinationWorkerNodeKey, task)
+ }
+ }
+ }
+
+ private updateTaskStolenStatisticsWorkerUsage (
+ workerNodeKey: number,
+ taskName: string
+ ): void {
+ const workerNode = this.workerNodes[workerNodeKey]
+ if (workerNode?.usage != null) {
+ ++workerNode.usage.tasks.stolen
+ }
+ if (
+ this.shallUpdateTaskFunctionWorkerUsage(workerNodeKey) &&
+ workerNode.getTaskFunctionWorkerUsage(taskName) != null
+ ) {
+ const taskFunctionWorkerUsage = workerNode.getTaskFunctionWorkerUsage(
+ taskName
+ ) as WorkerUsage
+ ++taskFunctionWorkerUsage.tasks.stolen
+ }
+ }
+
+ private taskStealingOnEmptyQueue (workerId: number): void {
+ const destinationWorkerNodeKey = this.getWorkerNodeKeyByWorkerId(workerId)
+ const destinationWorkerNode = this.workerNodes[destinationWorkerNodeKey]
+ const workerNodes = this.workerNodes
+ .slice()
+ .sort(
+ (workerNodeA, workerNodeB) =>
+ workerNodeB.usage.tasks.queued - workerNodeA.usage.tasks.queued
+ )
+ const sourceWorkerNode = workerNodes.find(
+ workerNode =>
+ workerNode.info.ready &&
+ workerNode.info.id !== workerId &&
+ workerNode.usage.tasks.queued > 0
+ )
+ if (sourceWorkerNode != null) {
+ const task = {
+ ...(sourceWorkerNode.popTask() as Task<Data>),
+ workerId: destinationWorkerNode.info.id as number
+ }
+ if (this.shallExecuteTask(destinationWorkerNodeKey)) {
+ this.executeTask(destinationWorkerNodeKey, task)
+ } else {
+ this.enqueueTask(destinationWorkerNodeKey, task)
+ }
+ this.updateTaskStolenStatisticsWorkerUsage(
+ destinationWorkerNodeKey,
+ task.name as string
+ )
+ }
+ }
+
+ private tasksStealingOnBackPressure (workerId: number): void {
+ const sizeOffset = 1
+ if ((this.opts.tasksQueueOptions?.size as number) <= sizeOffset) {
+ return
+ }
+ const sourceWorkerNode =
+ this.workerNodes[this.getWorkerNodeKeyByWorkerId(workerId)]
+ const workerNodes = this.workerNodes
+ .slice()
+ .sort(
+ (workerNodeA, workerNodeB) =>
+ workerNodeA.usage.tasks.queued - workerNodeB.usage.tasks.queued
+ )
+ for (const [workerNodeKey, workerNode] of workerNodes.entries()) {
+ if (
+ sourceWorkerNode.usage.tasks.queued > 0 &&
+ workerNode.info.ready &&
+ workerNode.info.id !== workerId &&
+ workerNode.usage.tasks.queued <
+ (this.opts.tasksQueueOptions?.size as number) - sizeOffset
+ ) {
+ const task = {
+ ...(sourceWorkerNode.popTask() as Task<Data>),
+ workerId: workerNode.info.id as number
}
- if (
- workerNodeId !== workerNodeKey &&
- workerInfo.ready &&
- workerNode.usage.tasks.queued < minQueuedTasks
- ) {
- minQueuedTasks = workerNode.usage.tasks.queued
- targetWorkerNodeKey = workerNodeId
+ if (this.shallExecuteTask(workerNodeKey)) {
+ this.executeTask(workerNodeKey, task)
+ } else {
+ this.enqueueTask(workerNodeKey, task)
}
+ this.updateTaskStolenStatisticsWorkerUsage(
+ workerNodeKey,
+ task.name as string
+ )
}
- this.enqueueTask(
- targetWorkerNodeKey,
- this.dequeueTask(workerNodeKey) as Task<Data>
- )
}
}
/**
- * This function is the listener registered for each worker message.
+ * This method is the listener registered for each worker message.
*
* @returns The listener function to execute when a message is received from a worker.
*/
protected workerListener (): (message: MessageValue<Response>) => void {
return message => {
this.checkMessageWorkerId(message)
- if (message.ready != null) {
- // Worker ready response received
+ if (message.ready != null && message.taskFunctions != null) {
+ // Worker ready response received from worker
this.handleWorkerReadyResponse(message)
- } else if (message.id != null) {
- // Task execution response received
+ } else if (message.taskId != null) {
+ // Task execution response received from worker
this.handleTaskExecutionResponse(message)
+ } else if (message.taskFunctions != null) {
+ // Task functions message received from worker
+ this.getWorkerInfo(
+ this.getWorkerNodeKeyByWorkerId(message.workerId)
+ ).taskFunctions = message.taskFunctions
}
}
}
private handleWorkerReadyResponse (message: MessageValue<Response>): void {
- this.getWorkerInfoByWorker(
- this.getWorkerById(message.workerId) as Worker
- ).ready = message.ready as boolean
+ if (message.ready === false) {
+ throw new Error(`Worker ${message.workerId} failed to initialize`)
+ }
+ const workerInfo = this.getWorkerInfo(
+ this.getWorkerNodeKeyByWorkerId(message.workerId)
+ )
+ workerInfo.ready = message.ready as boolean
+ workerInfo.taskFunctions = message.taskFunctions
if (this.emitter != null && this.ready) {
this.emitter.emit(PoolEvents.ready, this.info)
}
}
private handleTaskExecutionResponse (message: MessageValue<Response>): void {
- const promiseResponse = this.promiseResponseMap.get(message.id as string)
+ const { taskId, taskError, data } = message
+ const promiseResponse = this.promiseResponseMap.get(taskId as string)
if (promiseResponse != null) {
- if (message.taskError != null) {
- this.emitter?.emit(PoolEvents.taskError, message.taskError)
- promiseResponse.reject(message.taskError.message)
+ if (taskError != null) {
+ this.emitter?.emit(PoolEvents.taskError, taskError)
+ promiseResponse.reject(taskError.message)
} else {
- promiseResponse.resolve(message.data as Response)
+ promiseResponse.resolve(data as Response)
}
- this.afterTaskExecutionHook(promiseResponse.worker, message)
- this.promiseResponseMap.delete(message.id as string)
- const workerNodeKey = this.getWorkerNodeKey(promiseResponse.worker)
+ const workerNodeKey = promiseResponse.workerNodeKey
+ this.afterTaskExecutionHook(workerNodeKey, message)
+ this.workerChoiceStrategyContext.update(workerNodeKey)
+ this.promiseResponseMap.delete(taskId as string)
if (
this.opts.enableTasksQueue === true &&
- this.tasksQueueSize(workerNodeKey) > 0
+ this.tasksQueueSize(workerNodeKey) > 0 &&
+ this.workerNodes[workerNodeKey].usage.tasks.executing <
+ (this.opts.tasksQueueOptions?.concurrency as number)
) {
this.executeTask(
workerNodeKey,
this.dequeueTask(workerNodeKey) as Task<Data>
)
}
- this.workerChoiceStrategyContext.update(workerNodeKey)
}
}
- private checkAndEmitEvents (): void {
- if (this.emitter != null) {
- if (this.busy) {
- this.emitter.emit(PoolEvents.busy, this.info)
- }
- if (this.type === PoolTypes.dynamic && this.full) {
- this.emitter.emit(PoolEvents.full, this.info)
- }
+ private checkAndEmitTaskExecutionEvents (): void {
+ if (this.busy) {
+ this.emitter?.emit(PoolEvents.busy, this.info)
}
}
- /**
- * 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
+ private checkAndEmitTaskQueuingEvents (): void {
+ if (this.hasBackPressure()) {
+ this.emitter?.emit(PoolEvents.backPressure, this.info)
+ }
+ }
+
+ private checkAndEmitDynamicWorkerCreationEvents (): void {
+ if (this.type === PoolTypes.dynamic) {
+ if (this.full) {
+ this.emitter?.emit(PoolEvents.full, this.info)
+ }
+ }
}
/**
- * Gets the worker information from the given worker.
+ * Gets the worker information given its worker node key.
*
- * @param worker - The worker.
+ * @param workerNodeKey - The worker node key.
* @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')
- }
+ protected getWorkerInfo (workerNodeKey: number): WorkerInfo {
return this.workerNodes[workerNodeKey].info
}
* Adds the given worker in the pool worker nodes.
*
* @param worker - The worker.
- * @returns The worker nodes length.
+ * @returns The added worker node key.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the added worker node is not found.
*/
private addWorkerNode (worker: Worker): number {
- const workerNode = new WorkerNode<Worker, Data>(worker, this.worker)
+ const workerNode = new WorkerNode<Worker, Data>(
+ worker,
+ this.opts.tasksQueueOptions?.size ?? Math.pow(this.maxSize, 2)
+ )
// Flag the worker node as ready at pool startup.
if (this.starting) {
workerNode.info.ready = true
}
- return this.workerNodes.push(workerNode)
+ this.workerNodes.push(workerNode)
+ const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
+ if (workerNodeKey === -1) {
+ throw new Error('Worker added not found in worker nodes')
+ }
+ return workerNodeKey
}
/**
* @param worker - The worker.
*/
private removeWorkerNode (worker: Worker): void {
- const workerNodeKey = this.getWorkerNodeKey(worker)
+ const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
if (workerNodeKey !== -1) {
this.workerNodes.splice(workerNodeKey, 1)
this.workerChoiceStrategyContext.remove(workerNodeKey)
}
}
+ /** @inheritDoc */
+ public hasWorkerNodeBackPressure (workerNodeKey: number): boolean {
+ return (
+ this.opts.enableTasksQueue === true &&
+ this.workerNodes[workerNodeKey].hasBackPressure()
+ )
+ }
+
+ private hasBackPressure (): boolean {
+ return (
+ this.opts.enableTasksQueue === true &&
+ this.workerNodes.findIndex(
+ workerNode => !workerNode.hasBackPressure()
+ ) === -1
+ )
+ }
+
/**
- * Executes the given task on the given worker.
+ * Executes the given task on the worker given its worker node key.
*
- * @param worker - The worker.
+ * @param workerNodeKey - The worker node key.
* @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)
+ this.sendToWorker(workerNodeKey, task, task.transferList)
+ this.checkAndEmitTaskExecutionEvents()
}
private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
- return this.workerNodes[workerNodeKey].enqueueTask(task)
+ const tasksQueueSize = this.workerNodes[workerNodeKey].enqueueTask(task)
+ this.checkAndEmitTaskQueuingEvents()
+ return tasksQueueSize
}
private dequeueTask (workerNodeKey: number): Task<Data> | undefined {
return this.workerNodes[workerNodeKey].tasksQueueSize()
}
- private flushTasksQueue (workerNodeKey: number): void {
+ protected flushTasksQueue (workerNodeKey: number): void {
while (this.tasksQueueSize(workerNodeKey) > 0) {
this.executeTask(
workerNodeKey,
this.flushTasksQueue(workerNodeKey)
}
}
-
- private setWorkerStatistics (worker: Worker): void {
- this.sendToWorker(worker, {
- statistics: {
- runTime:
- this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
- .runTime.aggregate,
- elu: this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
- .elu.aggregate
- },
- workerId: this.getWorkerInfoByWorker(worker).id as number
- })
- }
}