-import crypto from 'node:crypto'
-import type { MessageValue, PromiseResponseWrapper } from '../utility-types'
+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,
+ Task
+} from '../utility-types'
import {
+ DEFAULT_TASK_NAME,
DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
EMPTY_FUNCTION,
+ isKillBehavior,
isPlainObject,
- median
+ median,
+ round,
+ updateMeasurementStatistics
} from '../utils'
-import { KillBehaviors, isKillBehavior } from '../worker/worker-options'
-import { CircularArray } from '../circular-array'
-import { Queue } from '../queue'
+import { KillBehaviors } from '../worker/worker-options'
import {
type IPool,
PoolEmitter,
PoolEvents,
+ type PoolInfo,
type PoolOptions,
- PoolType,
+ type PoolType,
+ PoolTypes,
type TasksQueueOptions
} from './pool'
-import type { IWorker, Task, TasksUsage, WorkerNode } from './worker'
+import type {
+ IWorker,
+ IWorkerNode,
+ WorkerInfo,
+ WorkerType,
+ WorkerUsage
+} from './worker'
import {
+ type MeasurementStatisticsRequirements,
+ Measurements,
WorkerChoiceStrategies,
type WorkerChoiceStrategy,
type WorkerChoiceStrategyOptions
} from './selection-strategies/selection-strategies-types'
import { WorkerChoiceStrategyContext } from './selection-strategies/worker-choice-strategy-context'
+import { version } from './version'
+import { WorkerNode } from './worker-node'
/**
* Base class that implements some shared logic for all poolifier pools.
*
* @typeParam Worker - Type of worker which manages this pool.
- * @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 abstract class AbstractPool<
Worker extends IWorker,
Response = unknown
> implements IPool<Worker, Data, Response> {
/** @inheritDoc */
- public readonly workerNodes: Array<WorkerNode<Worker, Data>> = []
+ public readonly workerNodes: Array<IWorkerNode<Worker, Data>> = []
/** @inheritDoc */
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.
- *
- * Default to a round robin algorithm.
*/
protected workerChoiceStrategyContext: WorkerChoiceStrategyContext<
Worker,
Response
>
+ /**
+ * Whether the pool is starting or not.
+ */
+ private readonly starting: boolean
+ /**
+ * The start timestamp of the pool.
+ */
+ private readonly startTimestamp
+
/**
* Constructs a new poolifier pool.
*
* @param opts - Options for the pool.
*/
public constructor (
- public readonly numberOfWorkers: number,
- public readonly filePath: string,
- public readonly opts: PoolOptions<Worker>
+ protected readonly numberOfWorkers: number,
+ protected readonly filePath: string,
+ 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.dequeueTask = this.dequeueTask.bind(this)
this.checkAndEmitEvents = this.checkAndEmitEvents.bind(this)
- this.setupHook()
-
- for (let i = 1; i <= this.numberOfWorkers; i++) {
- this.createAndSetupWorker()
- }
-
if (this.opts.enableEvents === true) {
this.emitter = new PoolEmitter()
}
this.opts.workerChoiceStrategy,
this.opts.workerChoiceStrategyOptions
)
+
+ this.setupHook()
+
+ 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 pool with a negative number of workers'
)
- } else if (this.type === PoolType.FIXED && numberOfWorkers === 0) {
- throw new Error('Cannot instantiate a fixed pool with no worker')
+ } else if (this.type === PoolTypes.fixed && numberOfWorkers === 0) {
+ throw new RangeError('Cannot instantiate a fixed pool with zero worker')
+ }
+ }
+
+ protected checkDynamicPoolSize (min: number, max: number): void {
+ if (this.type === PoolTypes.dynamic) {
+ if (max == null) {
+ throw new Error(
+ '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 maximum pool size equal to zero'
+ )
+ } else if (min === max) {
+ throw new RangeError(
+ 'Cannot instantiate a dynamic pool with a minimum pool size equal to the maximum pool size. Use a fixed pool instead'
+ )
+ }
}
}
this.checkValidWorkerChoiceStrategyOptions(
this.opts.workerChoiceStrategyOptions
)
+ this.opts.restartWorkerOnError = opts.restartWorkerOnError ?? true
this.opts.enableEvents = opts.enableEvents ?? true
this.opts.enableTasksQueue = opts.enableTasksQueue ?? false
if (this.opts.enableTasksQueue) {
}
if (
workerChoiceStrategyOptions.weights != null &&
- Object.keys(workerChoiceStrategyOptions.weights).length !== this.size
+ Object.keys(workerChoiceStrategyOptions.weights).length !== this.maxSize
) {
throw new Error(
'Invalid worker choice strategy options: must have a weight for each worker node'
)
}
+ if (
+ workerChoiceStrategyOptions.measurement != null &&
+ !Object.values(Measurements).includes(
+ workerChoiceStrategyOptions.measurement
+ )
+ ) {
+ throw new Error(
+ `Invalid worker choice strategy options: invalid measurement '${workerChoiceStrategyOptions.measurement}'`
+ )
+ }
}
private checkValidTasksQueueOptions (
if (tasksQueueOptions != null && !isPlainObject(tasksQueueOptions)) {
throw new TypeError('Invalid tasks queue options: must be a plain object')
}
- if ((tasksQueueOptions?.concurrency as number) <= 0) {
+ if (
+ tasksQueueOptions?.concurrency != null &&
+ !Number.isSafeInteger(tasksQueueOptions.concurrency)
+ ) {
+ throw new TypeError(
+ 'Invalid worker tasks concurrency: must be an integer'
+ )
+ }
+ if (
+ tasksQueueOptions?.concurrency != null &&
+ tasksQueueOptions.concurrency <= 0
+ ) {
throw new Error(
- `Invalid worker tasks concurrency '${
- tasksQueueOptions.concurrency as number
- }'`
+ `Invalid worker tasks concurrency '${tasksQueueOptions.concurrency}'`
)
}
}
- /** @inheritDoc */
- public abstract get type (): PoolType
+ private startPool (): void {
+ while (
+ this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ !workerNode.info.dynamic ? accumulator + 1 : accumulator,
+ 0
+ ) < this.numberOfWorkers
+ ) {
+ this.createAndSetupWorkerNode()
+ }
+ }
/** @inheritDoc */
- public abstract get size (): number
+ public get info (): PoolInfo {
+ return {
+ version,
+ type: this.type,
+ worker: this.worker,
+ ready: this.ready,
+ strategy: this.opts.workerChoiceStrategy as WorkerChoiceStrategy,
+ minSize: this.minSize,
+ maxSize: this.maxSize,
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.aggregate &&
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.aggregate && { utilization: round(this.utilization) }),
+ workerNodes: this.workerNodes.length,
+ idleWorkerNodes: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ workerNode.usage.tasks.executing === 0
+ ? accumulator + 1
+ : accumulator,
+ 0
+ ),
+ busyWorkerNodes: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ workerNode.usage.tasks.executing > 0 ? accumulator + 1 : accumulator,
+ 0
+ ),
+ executedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.executed,
+ 0
+ ),
+ executingTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.executing,
+ 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
+ )
+ }),
+ failedTasks: this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + workerNode.usage.tasks.failed,
+ 0
+ ),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .runTime.aggregate && {
+ runTime: {
+ minimum: round(
+ Math.min(
+ ...this.workerNodes.map(
+ (workerNode) => workerNode.usage.runTime?.minimum ?? Infinity
+ )
+ )
+ ),
+ maximum: round(
+ Math.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.median && {
+ median: round(
+ median(
+ this.workerNodes.map(
+ (workerNode) => workerNode.usage.runTime?.median ?? 0
+ )
+ )
+ )
+ })
+ }
+ }),
+ ...(this.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+ .waitTime.aggregate && {
+ waitTime: {
+ minimum: round(
+ Math.min(
+ ...this.workerNodes.map(
+ (workerNode) => workerNode.usage.waitTime?.minimum ?? Infinity
+ )
+ )
+ ),
+ maximum: round(
+ Math.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.median && {
+ median: round(
+ median(
+ this.workerNodes.map(
+ (workerNode) => workerNode.usage.waitTime?.median ?? 0
+ )
+ )
+ )
+ })
+ }
+ })
+ }
+ }
/**
- * Number of tasks running in the pool.
+ * The pool readiness boolean status.
*/
- private get numberOfRunningTasks (): number {
- return this.workerNodes.reduce(
- (accumulator, workerNode) => accumulator + workerNode.tasksUsage.running,
- 0
+ private get ready (): boolean {
+ return (
+ this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ !workerNode.info.dynamic && workerNode.info.ready
+ ? accumulator + 1
+ : accumulator,
+ 0
+ ) >= this.minSize
)
}
/**
- * Number of tasks queued in the pool.
+ * The approximate pool utilization.
+ *
+ * @returns The pool utilization.
*/
- private get numberOfQueuedTasks (): number {
- if (this.opts.enableTasksQueue === false) {
- return 0
- }
- return this.workerNodes.reduce(
- (accumulator, workerNode) => accumulator + workerNode.tasksQueue.size,
+ private get utilization (): number {
+ const poolTimeCapacity =
+ (performance.now() - this.startTimestamp) * this.maxSize
+ const totalTasksRunTime = this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + (workerNode.usage.runTime?.aggregate ?? 0),
0
)
+ const totalTasksWaitTime = this.workerNodes.reduce(
+ (accumulator, workerNode) =>
+ accumulator + (workerNode.usage.waitTime?.aggregate ?? 0),
+ 0
+ )
+ return (totalTasksRunTime + totalTasksWaitTime) / poolTimeCapacity
+ }
+
+ /**
+ * The pool type.
+ *
+ * If it is `'dynamic'`, it provides the `max` property.
+ */
+ protected abstract get type (): PoolType
+
+ /**
+ * The worker type.
+ */
+ protected abstract get worker (): WorkerType
+
+ /**
+ * The pool minimum size.
+ */
+ protected abstract get minSize (): number
+
+ /**
+ * The pool maximum size.
+ */
+ protected abstract get maxSize (): number
+
+ /**
+ * 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 &&
+ this.getWorkerNodeKeyByWorkerId(message.workerId) === -1
+ ) {
+ throw new Error(
+ `Worker message received from unknown worker '${message.workerId}'`
+ )
+ }
}
/**
* Gets the given worker its worker node key.
*
* @param worker - The worker.
- * @returns The worker node key if the worker is found in the pool worker nodes, `-1` otherwise.
+ * @returns The worker node key if found in the pool worker nodes, `-1` otherwise.
*/
- private getWorkerNodeKey (worker: Worker): number {
+ private getWorkerNodeKeyByWorker (worker: Worker): number {
return this.workerNodes.findIndex(
- workerNode => workerNode.worker === worker
+ (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
)
}
): void {
this.checkValidWorkerChoiceStrategy(workerChoiceStrategy)
this.opts.workerChoiceStrategy = workerChoiceStrategy
- for (const workerNode of this.workerNodes) {
- this.setWorkerNodeTasksUsage(workerNode, {
- run: 0,
- running: 0,
- runTime: 0,
- runTimeHistory: new CircularArray(),
- avgRunTime: 0,
- medRunTime: 0,
- waitTime: 0,
- waitTimeHistory: new CircularArray(),
- avgWaitTime: 0,
- medWaitTime: 0,
- error: 0
- })
- }
this.workerChoiceStrategyContext.setWorkerChoiceStrategy(
this.opts.workerChoiceStrategy
)
if (workerChoiceStrategyOptions != null) {
this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
}
+ for (const [workerNodeKey, workerNode] of this.workerNodes.entries()) {
+ workerNode.resetUsage()
+ this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
+ }
}
/** @inheritDoc */
this.checkValidTasksQueueOptions(tasksQueueOptions)
this.opts.tasksQueueOptions =
this.buildTasksQueueOptions(tasksQueueOptions)
- } else {
+ } else if (this.opts.tasksQueueOptions != null) {
delete this.opts.tasksQueueOptions
}
}
*
* The pool filling boolean status.
*/
- protected abstract get full (): boolean
+ protected get full (): boolean {
+ return this.workerNodes.length >= this.maxSize
+ }
/**
* Whether the pool is busy or not.
*/
protected abstract get busy (): boolean
+ /**
+ * Whether worker nodes are executing concurrently their tasks quota or not.
+ *
+ * @returns Worker nodes busyness boolean status.
+ */
protected internalBusy (): boolean {
- return (
- this.workerNodes.findIndex(workerNode => {
- return workerNode.tasksUsage.running === 0
- }) === -1
- )
+ 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 async execute (data?: Data, name?: string): Promise<Response> {
- const submissionTimestamp = performance.now()
- const workerNodeKey = this.chooseWorkerNode()
- const submittedTask: Task<Data> = {
- name,
- // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
- data: data ?? ({} as Data),
- submissionTimestamp,
- id: crypto.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 (name != null && typeof name !== 'string') {
+ reject(new TypeError('name argument must be a string'))
+ }
+ if (transferList != null && !Array.isArray(transferList)) {
+ reject(new TypeError('transferList argument must be an array'))
+ }
+ 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.workerNodes[workerNodeKey].usage.tasks.executing <
+ (this.opts.tasksQueueOptions?.concurrency as number))
+ ) {
+ this.executeTask(workerNodeKey, task)
+ } else {
+ this.enqueueTask(workerNodeKey, task)
+ }
+ this.checkAndEmitEvents()
})
- if (
- this.opts.enableTasksQueue === true &&
- (this.busy ||
- this.workerNodes[workerNodeKey].tasksUsage.running >=
- ((this.opts.tasksQueueOptions as TasksQueueOptions)
- .concurrency as number))
- ) {
- this.enqueueTask(workerNodeKey, submittedTask)
- } else {
- this.executeTask(workerNodeKey, submittedTask)
- }
- this.workerChoiceStrategyContext.update(workerNodeKey)
- 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)
- await this.destroyWorker(workerNode.worker)
+ this.workerNodes.map(async (_, workerNodeKey) => {
+ await this.destroyWorkerNode(workerNodeKey)
})
)
}
+ protected async sendKillMessageToWorker (
+ workerNodeKey: number,
+ workerId: number
+ ): Promise<void> {
+ const waitForKillResponse = 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 })
+ await waitForKillResponse
+ }
+
/**
- * Shutdowns 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 node are created in the abstract constructor.
- * Can be overridden
+ * Setup hook to execute code before worker nodes are created in the abstract constructor.
+ * Can be overridden.
*
* @virtual
*/
* Can be overridden.
*
* @param workerNodeKey - The worker node key.
+ * @param task - The task to execute.
*/
- protected beforeTaskExecutionHook (workerNodeKey: number): void {
- ++this.workerNodes[workerNodeKey].tasksUsage.running
+ protected beforeTaskExecutionHook (
+ 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)
}
/**
* 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 workerTasksUsage =
- this.workerNodes[this.getWorkerNodeKey(worker)].tasksUsage
- --workerTasksUsage.running
- ++workerTasksUsage.run
- if (message.error != null) {
- ++workerTasksUsage.error
- }
- this.updateRunTimeTasksUsage(workerTasksUsage, message)
- this.updateWaitTasksUsage(workerTasksUsage, message)
+ 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)
}
- private updateRunTimeTasksUsage (
- workerTasksUsage: TasksUsage,
+ private updateTaskStatisticsWorkerUsage (
+ workerUsage: WorkerUsage,
message: MessageValue<Response>
): void {
- if (this.workerChoiceStrategyContext.getRequiredStatistics().runTime) {
- workerTasksUsage.runTime += message.runTime ?? 0
- if (
- this.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime &&
- workerTasksUsage.run !== 0
- ) {
- workerTasksUsage.avgRunTime =
- workerTasksUsage.runTime / workerTasksUsage.run
- }
- if (
- this.workerChoiceStrategyContext.getRequiredStatistics().medRunTime &&
- message.runTime != null
- ) {
- workerTasksUsage.runTimeHistory.push(message.runTime)
- workerTasksUsage.medRunTime = median(workerTasksUsage.runTimeHistory)
- }
+ const workerTaskStatistics = workerUsage.tasks
+ --workerTaskStatistics.executing
+ if (message.taskError == null) {
+ ++workerTaskStatistics.executed
+ } else {
+ ++workerTaskStatistics.failed
}
}
- private updateWaitTasksUsage (
- workerTasksUsage: TasksUsage,
+ private updateRunTimeWorkerUsage (
+ workerUsage: WorkerUsage,
message: MessageValue<Response>
): void {
- if (this.workerChoiceStrategyContext.getRequiredStatistics().waitTime) {
- workerTasksUsage.waitTime += message.waitTime ?? 0
- if (
- this.workerChoiceStrategyContext.getRequiredStatistics().avgWaitTime &&
- workerTasksUsage.run !== 0
- ) {
- workerTasksUsage.avgWaitTime =
- workerTasksUsage.waitTime / workerTasksUsage.run
- }
- if (
- this.workerChoiceStrategyContext.getRequiredStatistics().medWaitTime &&
- message.waitTime != null
- ) {
- workerTasksUsage.waitTimeHistory.push(message.waitTime)
- workerTasksUsage.medWaitTime = median(workerTasksUsage.waitTimeHistory)
+ updateMeasurementStatistics(
+ workerUsage.runTime,
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().runTime,
+ message.taskPerformance?.runTime ?? 0,
+ workerUsage.tasks.executed
+ )
+ }
+
+ private updateWaitTimeWorkerUsage (
+ workerUsage: WorkerUsage,
+ task: Task<Data>
+ ): void {
+ const timestamp = performance.now()
+ const taskWaitTime = timestamp - (task.timestamp ?? timestamp)
+ updateMeasurementStatistics(
+ workerUsage.waitTime,
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().waitTime,
+ taskWaitTime,
+ workerUsage.tasks.executed
+ )
+ }
+
+ private updateEluWorkerUsage (
+ workerUsage: WorkerUsage,
+ message: MessageValue<Response>
+ ): void {
+ const eluTaskStatisticsRequirements: MeasurementStatisticsRequirements =
+ this.workerChoiceStrategyContext.getTaskStatisticsRequirements().elu
+ 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) {
+ if (workerUsage.elu.utilization != null) {
+ workerUsage.elu.utilization =
+ (workerUsage.elu.utilization +
+ message.taskPerformance.elu.utilization) /
+ 2
+ } else {
+ workerUsage.elu.utilization = message.taskPerformance.elu.utilization
+ }
}
}
}
/**
* Chooses a worker node for the next task.
*
- * The default worker choice strategy uses a round robin algorithm to distribute the load.
+ * The default worker choice strategy uses a round robin algorithm to distribute the tasks.
*
- * @returns The worker node key
- */
- protected chooseWorkerNode (): number {
- let workerNodeKey: number
- if (this.type === PoolType.DYNAMIC && !this.full && this.internalBusy()) {
- const workerCreated = this.createAndSetupWorker()
- this.registerWorkerMessageListener(workerCreated, message => {
- const currentWorkerNodeKey = this.getWorkerNodeKey(workerCreated)
- if (
- isKillBehavior(KillBehaviors.HARD, message.kill) ||
- (message.kill != null &&
- this.workerNodes[currentWorkerNodeKey].tasksUsage.running === 0)
- ) {
- // Kill message received from the worker: no new tasks are submitted to that worker for a while ( > maxInactiveTime)
- this.flushTasksQueue(currentWorkerNodeKey)
- void (this.destroyWorker(workerCreated) as Promise<void>)
- }
- })
- workerNodeKey = this.getWorkerNodeKey(workerCreated)
- } else {
- workerNodeKey = this.workerChoiceStrategyContext.execute()
+ * @returns The chosen worker node key
+ */
+ private chooseWorkerNode (): number {
+ if (this.shallCreateDynamicWorker()) {
+ const workerNodeKey = this.createAndSetupDynamicWorkerNode()
+ if (
+ this.workerChoiceStrategyContext.getStrategyPolicy().useDynamicWorker
+ ) {
+ return workerNodeKey
+ }
}
- return workerNodeKey
+ return this.workerChoiceStrategyContext.execute()
}
/**
- * Sends a message to the given worker.
+ * Conditions for dynamic worker creation.
*
- * @param worker - The worker which should receive the message.
- * @param message - The message.
+ * @returns Whether to create a dynamic worker or not.
*/
- protected abstract sendToWorker (
- worker: Worker,
- message: MessageValue<Data>
- ): void
+ private shallCreateDynamicWorker (): boolean {
+ return this.type === PoolTypes.dynamic && !this.full && this.internalBusy()
+ }
/**
- * Registers a listener callback on the given worker.
+ * Sends a message to worker given its worker node key.
*
- * @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
-
- /**
- * Returns a newly created worker.
+ * @param workerNodeKey - The worker node key.
+ * @param message - The message.
+ * @param transferList - The optional array of transferable objects.
*/
- protected abstract createWorker (): Worker
+ protected abstract sendToWorker (
+ workerNodeKey: number,
+ message: MessageValue<Data>,
+ transferList?: TransferListItem[]
+ ): void
/**
- * Function that can be hooked up when a worker has been newly created and moved to the pool worker nodes.
- *
- * Can be used to update the `maxListeners` or binding the `main-worker`\<-\>`worker` connection if not bind by default.
+ * Creates a new worker.
*
- * @param worker - The newly created worker.
+ * @returns Newly created worker.
*/
- protected abstract afterWorkerSetup (worker: Worker): 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('message', this.opts.messageHandler ?? EMPTY_FUNCTION)
worker.on('error', this.opts.errorHandler ?? EMPTY_FUNCTION)
+ worker.on('error', (error) => {
+ 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 (workerInfo.dynamic) {
+ this.createAndSetupDynamicWorkerNode()
+ } else {
+ 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.removeWorkerNode(worker)
})
- this.pushWorkerNode(worker)
+ const workerNodeKey = this.addWorkerNode(worker)
- this.afterWorkerSetup(worker)
+ this.afterWorkerNodeSetup(workerNodeKey)
- return worker
+ return workerNodeKey
}
/**
- * This function is the listener registered for each worker message.
+ * Creates a new, completely set up dynamic worker node.
*
- * @returns The listener function to execute when a message is received from a worker.
+ * @returns New, completely set up dynamic worker node key.
*/
- protected workerListener (): (message: MessageValue<Response>) => void {
- return message => {
- if (message.id != null) {
- // Task execution response received
- const promiseResponse = this.promiseResponseMap.get(message.id)
- if (promiseResponse != null) {
- if (message.error != null) {
- promiseResponse.reject(message.error)
- } else {
- promiseResponse.resolve(message.data as Response)
- }
- this.afterTaskExecutionHook(promiseResponse.worker, message)
- this.promiseResponseMap.delete(message.id)
- const workerNodeKey = this.getWorkerNodeKey(promiseResponse.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) ||
+ (isKillBehavior(KillBehaviors.SOFT, message.kill) &&
+ ((this.opts.enableTasksQueue === false &&
+ workerUsage.tasks.executing === 0) ||
+ (this.opts.enableTasksQueue === true &&
+ workerUsage.tasks.executing === 0 &&
+ this.tasksQueueSize(localWorkerNodeKey) === 0)))
+ ) {
+ this.destroyWorkerNode(localWorkerNodeKey).catch((error) => {
+ this.emitter?.emit(PoolEvents.error, error)
+ })
+ }
+ })
+ const workerInfo = this.getWorkerInfo(workerNodeKey)
+ this.sendToWorker(workerNodeKey, {
+ checkActive: true,
+ workerId: workerInfo.id as number
+ })
+ workerInfo.dynamic = true
+ if (this.workerChoiceStrategyContext.getStrategyPolicy().useDynamicWorker) {
+ workerInfo.ready = true
+ }
+ return workerNodeKey
+ }
+
+ /**
+ * Registers a listener callback on the worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @param listener - The message listener callback.
+ */
+ protected abstract registerWorkerMessageListener<
+ Message extends Data | Response
+ >(
+ workerNodeKey: number,
+ listener: (message: MessageValue<Message>) => void
+ ): void
+
+ /**
+ * Method hooked up after a worker node has been newly created.
+ * Can be overridden.
+ *
+ * @param workerNodeKey - The newly created worker node key.
+ */
+ protected afterWorkerNodeSetup (workerNodeKey: number): void {
+ // Listen to worker messages.
+ this.registerWorkerMessageListener(workerNodeKey, this.workerListener())
+ // Send the startup message to worker.
+ this.sendStartupMessageToWorker(workerNodeKey)
+ // Send the worker statistics message to worker.
+ this.sendWorkerStatisticsMessageToWorker(workerNodeKey)
+ }
+
+ /**
+ * Sends the startup message to worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ */
+ protected abstract sendStartupMessageToWorker (workerNodeKey: number): void
+
+ /**
+ * Sends the worker statistics message to worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ */
+ private sendWorkerStatisticsMessageToWorker (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
+ let executeTask = false
+ for (const [workerNodeId, workerNode] of this.workerNodes.entries()) {
+ const workerInfo = this.getWorkerInfo(workerNodeId)
+ if (
+ workerNodeId !== workerNodeKey &&
+ workerInfo.ready &&
+ workerNode.usage.tasks.queued === 0
+ ) {
if (
- this.opts.enableTasksQueue === true &&
- this.tasksQueueSize(workerNodeKey) > 0
+ this.workerNodes[workerNodeId].usage.tasks.executing <
+ (this.opts.tasksQueueOptions?.concurrency as number)
) {
- this.executeTask(
- workerNodeKey,
- this.dequeueTask(workerNodeKey) as Task<Data>
- )
+ executeTask = true
}
+ targetWorkerNodeKey = workerNodeId
+ break
+ }
+ if (
+ workerNodeId !== workerNodeKey &&
+ workerInfo.ready &&
+ workerNode.usage.tasks.queued < minQueuedTasks
+ ) {
+ minQueuedTasks = workerNode.usage.tasks.queued
+ targetWorkerNodeKey = workerNodeId
}
}
+ if (executeTask) {
+ this.executeTask(
+ targetWorkerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ } else {
+ this.enqueueTask(
+ targetWorkerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ }
+ }
+ }
+
+ /**
+ * 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 from worker
+ this.handleWorkerReadyResponse(message)
+ } else if (message.taskId != null) {
+ // Task execution response received from worker
+ this.handleTaskExecutionResponse(message)
+ }
+ }
+ }
+
+ private handleWorkerReadyResponse (message: MessageValue<Response>): void {
+ this.getWorkerInfo(
+ this.getWorkerNodeKeyByWorkerId(message.workerId)
+ ).ready = message.ready as boolean
+ 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.taskId as string
+ )
+ if (promiseResponse != null) {
+ if (message.taskError != null) {
+ this.emitter?.emit(PoolEvents.taskError, message.taskError)
+ promiseResponse.reject(message.taskError.message)
+ } else {
+ promiseResponse.resolve(message.data as Response)
+ }
+ const workerNodeKey = promiseResponse.workerNodeKey
+ this.afterTaskExecutionHook(workerNodeKey, message)
+ this.promiseResponseMap.delete(message.taskId as string)
+ if (
+ this.opts.enableTasksQueue === true &&
+ 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.opts.enableEvents === true) {
+ if (this.emitter != null) {
if (this.busy) {
- this.emitter?.emit(PoolEvents.busy)
+ this.emitter.emit(PoolEvents.busy, this.info)
}
- if (this.type === PoolType.DYNAMIC && this.full) {
- this.emitter?.emit(PoolEvents.full)
+ if (this.type === PoolTypes.dynamic && this.full) {
+ this.emitter.emit(PoolEvents.full, this.info)
}
}
}
/**
- * Sets the given worker node its tasks usage in the pool.
+ * Gets the worker information given its worker node key.
*
- * @param workerNode - The worker node.
- * @param tasksUsage - The worker node tasks usage.
+ * @param workerNodeKey - The worker node key.
+ * @returns The worker information.
*/
- private setWorkerNodeTasksUsage (
- workerNode: WorkerNode<Worker, Data>,
- tasksUsage: TasksUsage
- ): void {
- workerNode.tasksUsage = tasksUsage
- }
-
- /**
- * Pushes 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({
- worker,
- tasksUsage: {
- run: 0,
- running: 0,
- runTime: 0,
- runTimeHistory: new CircularArray(),
- avgRunTime: 0,
- medRunTime: 0,
- waitTime: 0,
- waitTimeHistory: new CircularArray(),
- avgWaitTime: 0,
- medWaitTime: 0,
- error: 0
- },
- tasksQueue: new Queue<Task<Data>>()
- })
+ protected getWorkerInfo (workerNodeKey: number): WorkerInfo {
+ return this.workerNodes[workerNodeKey].info
}
/**
- * Sets the given worker in the pool worker nodes.
+ * Adds the given worker in the pool worker nodes.
*
- * @param workerNodeKey - The worker node key.
* @param worker - The worker.
- * @param tasksUsage - The worker tasks usage.
- * @param tasksQueue - The worker task queue.
+ * @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 setWorkerNode (
- workerNodeKey: number,
- worker: Worker,
- tasksUsage: TasksUsage,
- tasksQueue: Queue<Task<Data>>
- ): void {
- this.workerNodes[workerNodeKey] = {
- worker,
- tasksUsage,
- tasksQueue
+ 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
}
+ this.workerNodes.push(workerNode)
+ const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
+ if (workerNodeKey === -1) {
+ throw new Error('Worker node not found')
+ }
+ return workerNodeKey
}
/**
* @param worker - The worker.
*/
private removeWorkerNode (worker: Worker): void {
- const workerNodeKey = this.getWorkerNodeKey(worker)
- this.workerNodes.splice(workerNodeKey, 1)
- this.workerChoiceStrategyContext.remove(workerNodeKey)
+ const workerNodeKey = this.getWorkerNodeKeyByWorker(worker)
+ if (workerNodeKey !== -1) {
+ this.workerNodes.splice(workerNodeKey, 1)
+ this.workerChoiceStrategyContext.remove(workerNodeKey)
+ }
}
+ /**
+ * Executes the given task on the worker given its worker node key.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @param task - The task to execute.
+ */
private executeTask (workerNodeKey: number, task: Task<Data>): void {
- this.beforeTaskExecutionHook(workerNodeKey)
- this.sendToWorker(this.workerNodes[workerNodeKey].worker, task)
+ this.beforeTaskExecutionHook(workerNodeKey, task)
+ this.sendToWorker(workerNodeKey, task, task.transferList)
}
private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
- return this.workerNodes[workerNodeKey].tasksQueue.enqueue(task)
+ return this.workerNodes[workerNodeKey].enqueueTask(task)
}
private dequeueTask (workerNodeKey: number): Task<Data> | undefined {
- return this.workerNodes[workerNodeKey].tasksQueue.dequeue()
+ return this.workerNodes[workerNodeKey].dequeueTask()
}
private tasksQueueSize (workerNodeKey: number): number {
- return this.workerNodes[workerNodeKey].tasksQueue.size
+ return this.workerNodes[workerNodeKey].tasksQueueSize()
}
- private flushTasksQueue (workerNodeKey: number): void {
- if (this.tasksQueueSize(workerNodeKey) > 0) {
- for (let i = 0; i < this.tasksQueueSize(workerNodeKey); i++) {
- this.executeTask(
- workerNodeKey,
- this.dequeueTask(workerNodeKey) as Task<Data>
- )
- }
+ protected flushTasksQueue (workerNodeKey: number): void {
+ while (this.tasksQueueSize(workerNodeKey) > 0) {
+ this.executeTask(
+ workerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
}
+ this.workerNodes[workerNodeKey].clearTasksQueue()
}
private flushTasksQueues (): void {