1 import { randomUUID
} from
'node:crypto'
2 import { performance
} from
'node:perf_hooks'
3 import { existsSync
} from
'node:fs'
6 PromiseResponseWrapper
,
8 } from
'../utility-types'
11 DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
,
17 updateMeasurementStatistics
19 import { KillBehaviors
} from
'../worker/worker-options'
28 type TasksQueueOptions
38 type MeasurementStatisticsRequirements
,
40 WorkerChoiceStrategies
,
41 type WorkerChoiceStrategy
,
42 type WorkerChoiceStrategyOptions
43 } from
'./selection-strategies/selection-strategies-types'
44 import { WorkerChoiceStrategyContext
} from
'./selection-strategies/worker-choice-strategy-context'
45 import { version
} from
'./version'
46 import { WorkerNode
} from
'./worker-node'
49 * Base class that implements some shared logic for all poolifier pools.
51 * @typeParam Worker - Type of worker which manages this pool.
52 * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
53 * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
55 export abstract class AbstractPool
<
56 Worker
extends IWorker
,
59 > implements IPool
<Worker
, Data
, Response
> {
61 public readonly workerNodes
: Array<IWorkerNode
<Worker
, Data
>> = []
64 public readonly emitter
?: PoolEmitter
67 * The task execution response promise map.
69 * - `key`: The message id of each submitted task.
70 * - `value`: An object that contains the worker, the execution response promise resolve and reject callbacks.
72 * When we receive a message from the worker, we get a map entry with the promise resolve/reject bound to the message id.
74 protected promiseResponseMap
: Map
<string, PromiseResponseWrapper
<Response
>> =
75 new Map
<string, PromiseResponseWrapper
<Response
>>()
78 * Worker choice strategy context referencing a worker choice algorithm implementation.
80 protected workerChoiceStrategyContext
: WorkerChoiceStrategyContext
<
87 * Whether the pool is starting or not.
89 private readonly starting
: boolean
91 * The start timestamp of the pool.
93 private readonly startTimestamp
96 * Constructs a new poolifier pool.
98 * @param numberOfWorkers - Number of workers that this pool should manage.
99 * @param filePath - Path to the worker file.
100 * @param opts - Options for the pool.
103 protected readonly numberOfWorkers
: number,
104 protected readonly filePath
: string,
105 protected readonly opts
: PoolOptions
<Worker
>
107 if (!this.isMain()) {
108 throw new Error('Cannot start a pool from a worker!')
110 this.checkNumberOfWorkers(this.numberOfWorkers
)
111 this.checkFilePath(this.filePath
)
112 this.checkPoolOptions(this.opts
)
114 this.chooseWorkerNode
= this.chooseWorkerNode
.bind(this)
115 this.executeTask
= this.executeTask
.bind(this)
116 this.enqueueTask
= this.enqueueTask
.bind(this)
117 this.dequeueTask
= this.dequeueTask
.bind(this)
118 this.checkAndEmitEvents
= this.checkAndEmitEvents
.bind(this)
120 if (this.opts
.enableEvents
=== true) {
121 this.emitter
= new PoolEmitter()
123 this.workerChoiceStrategyContext
= new WorkerChoiceStrategyContext
<
129 this.opts
.workerChoiceStrategy
,
130 this.opts
.workerChoiceStrategyOptions
137 this.starting
= false
139 this.startTimestamp
= performance
.now()
142 private checkFilePath (filePath
: string): void {
145 typeof filePath
!== 'string' ||
146 (typeof filePath
=== 'string' && filePath
.trim().length
=== 0)
148 throw new Error('Please specify a file with a worker implementation')
150 if (!existsSync(filePath
)) {
151 throw new Error(`Cannot find the worker file '${filePath}'`)
155 private checkNumberOfWorkers (numberOfWorkers
: number): void {
156 if (numberOfWorkers
== null) {
158 'Cannot instantiate a pool without specifying the number of workers'
160 } else if (!Number.isSafeInteger(numberOfWorkers
)) {
162 'Cannot instantiate a pool with a non safe integer number of workers'
164 } else if (numberOfWorkers
< 0) {
165 throw new RangeError(
166 'Cannot instantiate a pool with a negative number of workers'
168 } else if (this.type === PoolTypes
.fixed
&& numberOfWorkers
=== 0) {
169 throw new RangeError('Cannot instantiate a fixed pool with zero worker')
173 protected checkDynamicPoolSize (min
: number, max
: number): void {
174 if (this.type === PoolTypes
.dynamic
) {
177 'Cannot instantiate a dynamic pool without specifying the maximum pool size'
179 } else if (!Number.isSafeInteger(max
)) {
181 'Cannot instantiate a dynamic pool with a non safe integer maximum pool size'
183 } else if (min
> max
) {
184 throw new RangeError(
185 'Cannot instantiate a dynamic pool with a maximum pool size inferior to the minimum pool size'
187 } else if (max
=== 0) {
188 throw new RangeError(
189 'Cannot instantiate a dynamic pool with a pool size equal to zero'
191 } else if (min
=== max
) {
192 throw new RangeError(
193 'Cannot instantiate a dynamic pool with a minimum pool size equal to the maximum pool size. Use a fixed pool instead'
199 private checkPoolOptions (opts
: PoolOptions
<Worker
>): void {
200 if (isPlainObject(opts
)) {
201 this.opts
.workerChoiceStrategy
=
202 opts
.workerChoiceStrategy
?? WorkerChoiceStrategies
.ROUND_ROBIN
203 this.checkValidWorkerChoiceStrategy(this.opts
.workerChoiceStrategy
)
204 this.opts
.workerChoiceStrategyOptions
=
205 opts
.workerChoiceStrategyOptions
??
206 DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
207 this.checkValidWorkerChoiceStrategyOptions(
208 this.opts
.workerChoiceStrategyOptions
210 this.opts
.restartWorkerOnError
= opts
.restartWorkerOnError
?? true
211 this.opts
.enableEvents
= opts
.enableEvents
?? true
212 this.opts
.enableTasksQueue
= opts
.enableTasksQueue
?? false
213 if (this.opts
.enableTasksQueue
) {
214 this.checkValidTasksQueueOptions(
215 opts
.tasksQueueOptions
as TasksQueueOptions
217 this.opts
.tasksQueueOptions
= this.buildTasksQueueOptions(
218 opts
.tasksQueueOptions
as TasksQueueOptions
222 throw new TypeError('Invalid pool options: must be a plain object')
226 private checkValidWorkerChoiceStrategy (
227 workerChoiceStrategy
: WorkerChoiceStrategy
229 if (!Object.values(WorkerChoiceStrategies
).includes(workerChoiceStrategy
)) {
231 `Invalid worker choice strategy '${workerChoiceStrategy}'`
236 private checkValidWorkerChoiceStrategyOptions (
237 workerChoiceStrategyOptions
: WorkerChoiceStrategyOptions
239 if (!isPlainObject(workerChoiceStrategyOptions
)) {
241 'Invalid worker choice strategy options: must be a plain object'
245 workerChoiceStrategyOptions
.weights
!= null &&
246 Object.keys(workerChoiceStrategyOptions
.weights
).length
!== this.maxSize
249 'Invalid worker choice strategy options: must have a weight for each worker node'
253 workerChoiceStrategyOptions
.measurement
!= null &&
254 !Object.values(Measurements
).includes(
255 workerChoiceStrategyOptions
.measurement
259 `Invalid worker choice strategy options: invalid measurement '${workerChoiceStrategyOptions.measurement}'`
264 private checkValidTasksQueueOptions (
265 tasksQueueOptions
: TasksQueueOptions
267 if (tasksQueueOptions
!= null && !isPlainObject(tasksQueueOptions
)) {
268 throw new TypeError('Invalid tasks queue options: must be a plain object')
271 tasksQueueOptions
?.concurrency
!= null &&
272 !Number.isSafeInteger(tasksQueueOptions
.concurrency
)
275 'Invalid worker tasks concurrency: must be an integer'
279 tasksQueueOptions
?.concurrency
!= null &&
280 tasksQueueOptions
.concurrency
<= 0
283 `Invalid worker tasks concurrency '${tasksQueueOptions.concurrency}'`
288 private startPool (): void {
290 this.workerNodes
.reduce(
291 (accumulator
, workerNode
) =>
292 !workerNode
.info
.dynamic
? accumulator
+ 1 : accumulator
,
294 ) < this.numberOfWorkers
296 this.createAndSetupWorkerNode()
301 public get
info (): PoolInfo
{
307 strategy
: this.opts
.workerChoiceStrategy
as WorkerChoiceStrategy
,
308 minSize
: this.minSize
,
309 maxSize
: this.maxSize
,
310 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
311 .runTime
.aggregate
&&
312 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
313 .waitTime
.aggregate
&& { utilization
: round(this.utilization
) }),
314 workerNodes
: this.workerNodes
.length
,
315 idleWorkerNodes
: this.workerNodes
.reduce(
316 (accumulator
, workerNode
) =>
317 workerNode
.usage
.tasks
.executing
=== 0
322 busyWorkerNodes
: this.workerNodes
.reduce(
323 (accumulator
, workerNode
) =>
324 workerNode
.usage
.tasks
.executing
> 0 ? accumulator
+ 1 : accumulator
,
327 executedTasks
: this.workerNodes
.reduce(
328 (accumulator
, workerNode
) =>
329 accumulator
+ workerNode
.usage
.tasks
.executed
,
332 executingTasks
: this.workerNodes
.reduce(
333 (accumulator
, workerNode
) =>
334 accumulator
+ workerNode
.usage
.tasks
.executing
,
337 ...(this.opts
.enableTasksQueue
=== true && {
338 queuedTasks
: this.workerNodes
.reduce(
339 (accumulator
, workerNode
) =>
340 accumulator
+ workerNode
.usage
.tasks
.queued
,
344 ...(this.opts
.enableTasksQueue
=== true && {
345 maxQueuedTasks
: this.workerNodes
.reduce(
346 (accumulator
, workerNode
) =>
347 accumulator
+ (workerNode
.usage
.tasks
?.maxQueued
?? 0),
351 failedTasks
: this.workerNodes
.reduce(
352 (accumulator
, workerNode
) =>
353 accumulator
+ workerNode
.usage
.tasks
.failed
,
356 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
357 .runTime
.aggregate
&& {
361 ...this.workerNodes
.map(
362 workerNode
=> workerNode
.usage
.runTime
?.minimum
?? Infinity
368 ...this.workerNodes
.map(
369 workerNode
=> workerNode
.usage
.runTime
?.maximum
?? -Infinity
374 this.workerNodes
.reduce(
375 (accumulator
, workerNode
) =>
376 accumulator
+ (workerNode
.usage
.runTime
?.aggregate
?? 0),
379 this.workerNodes
.reduce(
380 (accumulator
, workerNode
) =>
381 accumulator
+ (workerNode
.usage
.tasks
?.executed
?? 0),
385 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
389 this.workerNodes
.map(
390 workerNode
=> workerNode
.usage
.runTime
?.median
?? 0
397 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
398 .waitTime
.aggregate
&& {
402 ...this.workerNodes
.map(
403 workerNode
=> workerNode
.usage
.waitTime
?.minimum
?? Infinity
409 ...this.workerNodes
.map(
410 workerNode
=> workerNode
.usage
.waitTime
?.maximum
?? -Infinity
415 this.workerNodes
.reduce(
416 (accumulator
, workerNode
) =>
417 accumulator
+ (workerNode
.usage
.waitTime
?.aggregate
?? 0),
420 this.workerNodes
.reduce(
421 (accumulator
, workerNode
) =>
422 accumulator
+ (workerNode
.usage
.tasks
?.executed
?? 0),
426 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
427 .waitTime
.median
&& {
430 this.workerNodes
.map(
431 workerNode
=> workerNode
.usage
.waitTime
?.median
?? 0
442 * The pool readiness boolean status.
444 private get
ready (): boolean {
446 this.workerNodes
.reduce(
447 (accumulator
, workerNode
) =>
448 !workerNode
.info
.dynamic
&& workerNode
.info
.ready
457 * The approximate pool utilization.
459 * @returns The pool utilization.
461 private get
utilization (): number {
462 const poolTimeCapacity
=
463 (performance
.now() - this.startTimestamp
) * this.maxSize
464 const totalTasksRunTime
= this.workerNodes
.reduce(
465 (accumulator
, workerNode
) =>
466 accumulator
+ (workerNode
.usage
.runTime
?.aggregate
?? 0),
469 const totalTasksWaitTime
= this.workerNodes
.reduce(
470 (accumulator
, workerNode
) =>
471 accumulator
+ (workerNode
.usage
.waitTime
?.aggregate
?? 0),
474 return (totalTasksRunTime
+ totalTasksWaitTime
) / poolTimeCapacity
480 * If it is `'dynamic'`, it provides the `max` property.
482 protected abstract get
type (): PoolType
487 protected abstract get
worker (): WorkerType
490 * The pool minimum size.
492 protected abstract get
minSize (): number
495 * The pool maximum size.
497 protected abstract get
maxSize (): number
500 * Checks if the worker id sent in the received message from a worker is valid.
502 * @param message - The received message.
503 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker id is invalid.
505 private checkMessageWorkerId (message
: MessageValue
<Response
>): void {
507 message
.workerId
!= null &&
508 this.getWorkerNodeKeyByWorkerId(message
.workerId
) === -1
511 `Worker message received from unknown worker '${message.workerId}'`
517 * Gets the given worker its worker node key.
519 * @param worker - The worker.
520 * @returns The worker node key if found in the pool worker nodes, `-1` otherwise.
522 private getWorkerNodeKeyByWorker (worker
: Worker
): number {
523 return this.workerNodes
.findIndex(
524 workerNode
=> workerNode
.worker
=== worker
529 * Gets the worker node key given its worker id.
531 * @param workerId - The worker id.
532 * @returns The worker node key if the worker id is found in the pool worker nodes, `-1` otherwise.
534 private getWorkerNodeKeyByWorkerId (workerId
: number): number {
535 return this.workerNodes
.findIndex(
536 workerNode
=> workerNode
.info
.id
=== workerId
541 public setWorkerChoiceStrategy (
542 workerChoiceStrategy
: WorkerChoiceStrategy
,
543 workerChoiceStrategyOptions
?: WorkerChoiceStrategyOptions
545 this.checkValidWorkerChoiceStrategy(workerChoiceStrategy
)
546 this.opts
.workerChoiceStrategy
= workerChoiceStrategy
547 this.workerChoiceStrategyContext
.setWorkerChoiceStrategy(
548 this.opts
.workerChoiceStrategy
550 if (workerChoiceStrategyOptions
!= null) {
551 this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions
)
553 for (const [workerNodeKey
, workerNode
] of this.workerNodes
.entries()) {
554 workerNode
.resetUsage()
555 this.sendWorkerStatisticsMessageToWorker(workerNodeKey
)
560 public setWorkerChoiceStrategyOptions (
561 workerChoiceStrategyOptions
: WorkerChoiceStrategyOptions
563 this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions
)
564 this.opts
.workerChoiceStrategyOptions
= workerChoiceStrategyOptions
565 this.workerChoiceStrategyContext
.setOptions(
566 this.opts
.workerChoiceStrategyOptions
571 public enableTasksQueue (
573 tasksQueueOptions
?: TasksQueueOptions
575 if (this.opts
.enableTasksQueue
=== true && !enable
) {
576 this.flushTasksQueues()
578 this.opts
.enableTasksQueue
= enable
579 this.setTasksQueueOptions(tasksQueueOptions
as TasksQueueOptions
)
583 public setTasksQueueOptions (tasksQueueOptions
: TasksQueueOptions
): void {
584 if (this.opts
.enableTasksQueue
=== true) {
585 this.checkValidTasksQueueOptions(tasksQueueOptions
)
586 this.opts
.tasksQueueOptions
=
587 this.buildTasksQueueOptions(tasksQueueOptions
)
588 } else if (this.opts
.tasksQueueOptions
!= null) {
589 delete this.opts
.tasksQueueOptions
593 private buildTasksQueueOptions (
594 tasksQueueOptions
: TasksQueueOptions
595 ): TasksQueueOptions
{
597 concurrency
: tasksQueueOptions
?.concurrency
?? 1
602 * Whether the pool is full or not.
604 * The pool filling boolean status.
606 protected get
full (): boolean {
607 return this.workerNodes
.length
>= this.maxSize
611 * Whether the pool is busy or not.
613 * The pool busyness boolean status.
615 protected abstract get
busy (): boolean
618 * Whether worker nodes are executing at least one task.
620 * @returns Worker nodes busyness boolean status.
622 protected internalBusy (): boolean {
624 this.workerNodes
.findIndex(
626 workerNode
.info
.ready
&& workerNode
.usage
.tasks
.executing
=== 0
632 public async execute (data
?: Data
, name
?: string): Promise
<Response
> {
633 return await new Promise
<Response
>((resolve
, reject
) => {
634 const timestamp
= performance
.now()
635 const workerNodeKey
= this.chooseWorkerNode()
636 const task
: Task
<Data
> = {
637 name
: name
?? DEFAULT_TASK_NAME
,
638 // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
639 data
: data
?? ({} as Data
),
641 workerId
: this.getWorkerInfo(workerNodeKey
).id
as number,
644 this.promiseResponseMap
.set(task
.id
as string, {
650 this.opts
.enableTasksQueue
=== false ||
651 (this.opts
.enableTasksQueue
=== true &&
652 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
<
653 (this.opts
.tasksQueueOptions
?.concurrency
as number))
655 this.executeTask(workerNodeKey
, task
)
657 this.enqueueTask(workerNodeKey
, task
)
659 this.checkAndEmitEvents()
664 public async destroy (): Promise
<void> {
666 this.workerNodes
.map(async (_
, workerNodeKey
) => {
667 await this.destroyWorkerNode(workerNodeKey
)
673 * Terminates the worker node given its worker node key.
675 * @param workerNodeKey - The worker node key.
677 protected abstract destroyWorkerNode (workerNodeKey
: number): Promise
<void>
680 * Setup hook to execute code before worker nodes are created in the abstract constructor.
685 protected setupHook (): void {
686 // Intentionally empty
690 * Should return whether the worker is the main worker or not.
692 protected abstract isMain (): boolean
695 * Hook executed before the worker task execution.
698 * @param workerNodeKey - The worker node key.
699 * @param task - The task to execute.
701 protected beforeTaskExecutionHook (
702 workerNodeKey
: number,
705 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
706 ++workerUsage
.tasks
.executing
707 this.updateWaitTimeWorkerUsage(workerUsage
, task
)
708 const taskWorkerUsage
= this.workerNodes
[workerNodeKey
].getTaskWorkerUsage(
711 ++taskWorkerUsage
.tasks
.executing
712 this.updateWaitTimeWorkerUsage(taskWorkerUsage
, task
)
716 * Hook executed after the worker task execution.
719 * @param workerNodeKey - The worker node key.
720 * @param message - The received message.
722 protected afterTaskExecutionHook (
723 workerNodeKey
: number,
724 message
: MessageValue
<Response
>
726 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
727 this.updateTaskStatisticsWorkerUsage(workerUsage
, message
)
728 this.updateRunTimeWorkerUsage(workerUsage
, message
)
729 this.updateEluWorkerUsage(workerUsage
, message
)
730 const taskWorkerUsage
= this.workerNodes
[workerNodeKey
].getTaskWorkerUsage(
731 message
.taskPerformance
?.name
?? DEFAULT_TASK_NAME
733 this.updateTaskStatisticsWorkerUsage(taskWorkerUsage
, message
)
734 this.updateRunTimeWorkerUsage(taskWorkerUsage
, message
)
735 this.updateEluWorkerUsage(taskWorkerUsage
, message
)
738 private updateTaskStatisticsWorkerUsage (
739 workerUsage
: WorkerUsage
,
740 message
: MessageValue
<Response
>
742 const workerTaskStatistics
= workerUsage
.tasks
743 --workerTaskStatistics
.executing
744 if (message
.taskError
== null) {
745 ++workerTaskStatistics
.executed
747 ++workerTaskStatistics
.failed
751 private updateRunTimeWorkerUsage (
752 workerUsage
: WorkerUsage
,
753 message
: MessageValue
<Response
>
755 updateMeasurementStatistics(
757 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements().runTime
,
758 message
.taskPerformance
?.runTime
?? 0,
759 workerUsage
.tasks
.executed
763 private updateWaitTimeWorkerUsage (
764 workerUsage
: WorkerUsage
,
767 const timestamp
= performance
.now()
768 const taskWaitTime
= timestamp
- (task
.timestamp
?? timestamp
)
769 updateMeasurementStatistics(
770 workerUsage
.waitTime
,
771 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements().waitTime
,
773 workerUsage
.tasks
.executed
777 private updateEluWorkerUsage (
778 workerUsage
: WorkerUsage
,
779 message
: MessageValue
<Response
>
781 const eluTaskStatisticsRequirements
: MeasurementStatisticsRequirements
=
782 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements().elu
783 updateMeasurementStatistics(
784 workerUsage
.elu
.active
,
785 eluTaskStatisticsRequirements
,
786 message
.taskPerformance
?.elu
?.active
?? 0,
787 workerUsage
.tasks
.executed
789 updateMeasurementStatistics(
790 workerUsage
.elu
.idle
,
791 eluTaskStatisticsRequirements
,
792 message
.taskPerformance
?.elu
?.idle
?? 0,
793 workerUsage
.tasks
.executed
795 if (eluTaskStatisticsRequirements
.aggregate
) {
796 if (message
.taskPerformance
?.elu
!= null) {
797 if (workerUsage
.elu
.utilization
!= null) {
798 workerUsage
.elu
.utilization
=
799 (workerUsage
.elu
.utilization
+
800 message
.taskPerformance
.elu
.utilization
) /
803 workerUsage
.elu
.utilization
= message
.taskPerformance
.elu
.utilization
810 * Chooses a worker node for the next task.
812 * The default worker choice strategy uses a round robin algorithm to distribute the tasks.
814 * @returns The chosen worker node key
816 private chooseWorkerNode (): number {
817 if (this.shallCreateDynamicWorker()) {
818 const workerNodeKey
= this.createAndSetupDynamicWorkerNode()
820 this.workerChoiceStrategyContext
.getStrategyPolicy().useDynamicWorker
825 return this.workerChoiceStrategyContext
.execute()
829 * Conditions for dynamic worker creation.
831 * @returns Whether to create a dynamic worker or not.
833 private shallCreateDynamicWorker (): boolean {
834 return this.type === PoolTypes
.dynamic
&& !this.full
&& this.internalBusy()
838 * Sends a message to worker given its worker node key.
840 * @param workerNodeKey - The worker node key.
841 * @param message - The message.
843 protected abstract sendToWorker (
844 workerNodeKey
: number,
845 message
: MessageValue
<Data
>
849 * Creates a new worker.
851 * @returns Newly created worker.
853 protected abstract createWorker (): Worker
856 * Creates a new, completely set up worker node.
858 * @returns New, completely set up worker node key.
860 protected createAndSetupWorkerNode (): number {
861 const worker
= this.createWorker()
863 worker
.on('message', this.opts
.messageHandler
?? EMPTY_FUNCTION
)
864 worker
.on('error', this.opts
.errorHandler
?? EMPTY_FUNCTION
)
865 worker
.on('error', error
=> {
866 const workerNodeKey
= this.getWorkerNodeKeyByWorker(worker
)
867 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
868 workerInfo
.ready
= false
869 this.workerNodes
[workerNodeKey
].closeChannel()
870 this.emitter
?.emit(PoolEvents
.error
, error
)
871 if (this.opts
.restartWorkerOnError
=== true && !this.starting
) {
872 if (workerInfo
.dynamic
) {
873 this.createAndSetupDynamicWorkerNode()
875 this.createAndSetupWorkerNode()
878 if (this.opts
.enableTasksQueue
=== true) {
879 this.redistributeQueuedTasks(workerNodeKey
)
882 worker
.on('online', this.opts
.onlineHandler
?? EMPTY_FUNCTION
)
883 worker
.on('exit', this.opts
.exitHandler
?? EMPTY_FUNCTION
)
884 worker
.once('exit', () => {
885 this.removeWorkerNode(worker
)
888 const workerNodeKey
= this.addWorkerNode(worker
)
890 this.afterWorkerNodeSetup(workerNodeKey
)
896 * Creates a new, completely set up dynamic worker node.
898 * @returns New, completely set up dynamic worker node key.
900 protected createAndSetupDynamicWorkerNode (): number {
901 const workerNodeKey
= this.createAndSetupWorkerNode()
902 this.registerWorkerMessageListener(workerNodeKey
, message
=> {
903 const localWorkerNodeKey
= this.getWorkerNodeKeyByWorkerId(
906 const workerUsage
= this.workerNodes
[localWorkerNodeKey
].usage
907 // Kill message received from worker
909 isKillBehavior(KillBehaviors
.HARD
, message
.kill
) ||
910 (message
.kill
!= null &&
911 ((this.opts
.enableTasksQueue
=== false &&
912 workerUsage
.tasks
.executing
=== 0) ||
913 (this.opts
.enableTasksQueue
=== true &&
914 workerUsage
.tasks
.executing
=== 0 &&
915 this.tasksQueueSize(localWorkerNodeKey
) === 0)))
917 this.destroyWorkerNode(localWorkerNodeKey
).catch(EMPTY_FUNCTION
)
920 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
921 this.sendToWorker(workerNodeKey
, {
923 workerId
: workerInfo
.id
as number
925 workerInfo
.dynamic
= true
926 if (this.workerChoiceStrategyContext
.getStrategyPolicy().useDynamicWorker
) {
927 workerInfo
.ready
= true
933 * Registers a listener callback on the worker given its worker node key.
935 * @param workerNodeKey - The worker node key.
936 * @param listener - The message listener callback.
938 protected abstract registerWorkerMessageListener
<
939 Message
extends Data
| Response
941 workerNodeKey
: number,
942 listener
: (message
: MessageValue
<Message
>) => void
946 * Method hooked up after a worker node has been newly created.
949 * @param workerNodeKey - The newly created worker node key.
951 protected afterWorkerNodeSetup (workerNodeKey
: number): void {
952 // Listen to worker messages.
953 this.registerWorkerMessageListener(workerNodeKey
, this.workerListener())
954 // Send the startup message to worker.
955 this.sendStartupMessageToWorker(workerNodeKey
)
956 // Send the worker statistics message to worker.
957 this.sendWorkerStatisticsMessageToWorker(workerNodeKey
)
961 * Sends the startup message to worker given its worker node key.
963 * @param workerNodeKey - The worker node key.
965 protected abstract sendStartupMessageToWorker (workerNodeKey
: number): void
968 * Sends the worker statistics message to worker given its worker node key.
970 * @param workerNodeKey - The worker node key.
972 private sendWorkerStatisticsMessageToWorker (workerNodeKey
: number): void {
973 this.sendToWorker(workerNodeKey
, {
976 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
978 elu
: this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
981 workerId
: this.getWorkerInfo(workerNodeKey
).id
as number
985 private redistributeQueuedTasks (workerNodeKey
: number): void {
986 while (this.tasksQueueSize(workerNodeKey
) > 0) {
987 let targetWorkerNodeKey
: number = workerNodeKey
988 let minQueuedTasks
= Infinity
989 let executeTask
= false
990 for (const [workerNodeId
, workerNode
] of this.workerNodes
.entries()) {
991 const workerInfo
= this.getWorkerInfo(workerNodeId
)
993 workerNodeId
!== workerNodeKey
&&
995 workerNode
.usage
.tasks
.queued
=== 0
998 this.workerNodes
[workerNodeId
].usage
.tasks
.executing
<
999 (this.opts
.tasksQueueOptions
?.concurrency
as number)
1003 targetWorkerNodeKey
= workerNodeId
1007 workerNodeId
!== workerNodeKey
&&
1009 workerNode
.usage
.tasks
.queued
< minQueuedTasks
1011 minQueuedTasks
= workerNode
.usage
.tasks
.queued
1012 targetWorkerNodeKey
= workerNodeId
1017 targetWorkerNodeKey
,
1018 this.dequeueTask(workerNodeKey
) as Task
<Data
>
1022 targetWorkerNodeKey
,
1023 this.dequeueTask(workerNodeKey
) as Task
<Data
>
1030 * This method is the listener registered for each worker message.
1032 * @returns The listener function to execute when a message is received from a worker.
1034 protected workerListener (): (message
: MessageValue
<Response
>) => void {
1036 this.checkMessageWorkerId(message
)
1037 if (message
.ready
!= null) {
1038 // Worker ready response received from worker
1039 this.handleWorkerReadyResponse(message
)
1040 } else if (message
.id
!= null) {
1041 // Task execution response received from worker
1042 this.handleTaskExecutionResponse(message
)
1047 private handleWorkerReadyResponse (message
: MessageValue
<Response
>): void {
1049 this.getWorkerNodeKeyByWorkerId(message
.workerId
)
1050 ).ready
= message
.ready
as boolean
1051 if (this.emitter
!= null && this.ready
) {
1052 this.emitter
.emit(PoolEvents
.ready
, this.info
)
1056 private handleTaskExecutionResponse (message
: MessageValue
<Response
>): void {
1057 const promiseResponse
= this.promiseResponseMap
.get(message
.id
as string)
1058 if (promiseResponse
!= null) {
1059 if (message
.taskError
!= null) {
1060 this.emitter
?.emit(PoolEvents
.taskError
, message
.taskError
)
1061 promiseResponse
.reject(message
.taskError
.message
)
1063 promiseResponse
.resolve(message
.data
as Response
)
1065 const workerNodeKey
= promiseResponse
.workerNodeKey
1066 this.afterTaskExecutionHook(workerNodeKey
, message
)
1067 this.promiseResponseMap
.delete(message
.id
as string)
1069 this.opts
.enableTasksQueue
=== true &&
1070 this.tasksQueueSize(workerNodeKey
) > 0 &&
1071 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
<
1072 (this.opts
.tasksQueueOptions
?.concurrency
as number)
1076 this.dequeueTask(workerNodeKey
) as Task
<Data
>
1079 this.workerChoiceStrategyContext
.update(workerNodeKey
)
1083 private checkAndEmitEvents (): void {
1084 if (this.emitter
!= null) {
1086 this.emitter
.emit(PoolEvents
.busy
, this.info
)
1088 if (this.type === PoolTypes
.dynamic
&& this.full
) {
1089 this.emitter
.emit(PoolEvents
.full
, this.info
)
1095 * Gets the worker information given its worker node key.
1097 * @param workerNodeKey - The worker node key.
1098 * @returns The worker information.
1100 protected getWorkerInfo (workerNodeKey
: number): WorkerInfo
{
1101 return this.workerNodes
[workerNodeKey
].info
1105 * Adds the given worker in the pool worker nodes.
1107 * @param worker - The worker.
1108 * @returns The added worker node key.
1109 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the added worker node is not found.
1111 private addWorkerNode (worker
: Worker
): number {
1112 const workerNode
= new WorkerNode
<Worker
, Data
>(worker
, this.worker
)
1113 // Flag the worker node as ready at pool startup.
1114 if (this.starting
) {
1115 workerNode
.info
.ready
= true
1117 this.workerNodes
.push(workerNode
)
1118 const workerNodeKey
= this.getWorkerNodeKeyByWorker(worker
)
1119 if (workerNodeKey
=== -1) {
1120 throw new Error('Worker node not found')
1122 return workerNodeKey
1126 * Removes the given worker from the pool worker nodes.
1128 * @param worker - The worker.
1130 private removeWorkerNode (worker
: Worker
): void {
1131 const workerNodeKey
= this.getWorkerNodeKeyByWorker(worker
)
1132 if (workerNodeKey
!== -1) {
1133 this.workerNodes
.splice(workerNodeKey
, 1)
1134 this.workerChoiceStrategyContext
.remove(workerNodeKey
)
1139 * Executes the given task on the worker given its worker node key.
1141 * @param workerNodeKey - The worker node key.
1142 * @param task - The task to execute.
1144 private executeTask (workerNodeKey
: number, task
: Task
<Data
>): void {
1145 this.beforeTaskExecutionHook(workerNodeKey
, task
)
1146 this.sendToWorker(workerNodeKey
, task
)
1149 private enqueueTask (workerNodeKey
: number, task
: Task
<Data
>): number {
1150 return this.workerNodes
[workerNodeKey
].enqueueTask(task
)
1153 private dequeueTask (workerNodeKey
: number): Task
<Data
> | undefined {
1154 return this.workerNodes
[workerNodeKey
].dequeueTask()
1157 private tasksQueueSize (workerNodeKey
: number): number {
1158 return this.workerNodes
[workerNodeKey
].tasksQueueSize()
1161 protected flushTasksQueue (workerNodeKey
: number): void {
1162 while (this.tasksQueueSize(workerNodeKey
) > 0) {
1165 this.dequeueTask(workerNodeKey
) as Task
<Data
>
1168 this.workerNodes
[workerNodeKey
].clearTasksQueue()
1171 private flushTasksQueues (): void {
1172 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
1173 this.flushTasksQueue(workerNodeKey
)