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
,
18 import { KillBehaviors
} from
'../worker/worker-options'
27 type TasksQueueOptions
39 WorkerChoiceStrategies
,
40 type WorkerChoiceStrategy
,
41 type WorkerChoiceStrategyOptions
42 } from
'./selection-strategies/selection-strategies-types'
43 import { WorkerChoiceStrategyContext
} from
'./selection-strategies/worker-choice-strategy-context'
44 import { version
} from
'./version'
45 import { WorkerNode
} from
'./worker-node'
48 * Base class that implements some shared logic for all poolifier pools.
50 * @typeParam Worker - Type of worker which manages this pool.
51 * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
52 * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
54 export abstract class AbstractPool
<
55 Worker
extends IWorker
,
58 > implements IPool
<Worker
, Data
, Response
> {
60 public readonly workerNodes
: Array<IWorkerNode
<Worker
, Data
>> = []
63 public readonly emitter
?: PoolEmitter
66 * The execution response promise map.
68 * - `key`: The message id of each submitted task.
69 * - `value`: An object that contains the worker, the execution response promise resolve and reject callbacks.
71 * When we receive a message from the worker, we get a map entry with the promise resolve/reject bound to the message id.
73 protected promiseResponseMap
: Map
<
75 PromiseResponseWrapper
<Worker
, Response
>
76 > = new Map
<string, PromiseResponseWrapper
<Worker
, Response
>>()
79 * Worker choice strategy context referencing a worker choice algorithm implementation.
81 protected workerChoiceStrategyContext
: WorkerChoiceStrategyContext
<
88 * The start timestamp of the pool.
90 private readonly startTimestamp
93 * Constructs a new poolifier pool.
95 * @param numberOfWorkers - Number of workers that this pool should manage.
96 * @param filePath - Path to the worker file.
97 * @param opts - Options for the pool.
100 protected readonly numberOfWorkers
: number,
101 protected readonly filePath
: string,
102 protected readonly opts
: PoolOptions
<Worker
>
104 if (!this.isMain()) {
105 throw new Error('Cannot start a pool from a worker!')
107 this.checkNumberOfWorkers(this.numberOfWorkers
)
108 this.checkFilePath(this.filePath
)
109 this.checkPoolOptions(this.opts
)
111 this.chooseWorkerNode
= this.chooseWorkerNode
.bind(this)
112 this.executeTask
= this.executeTask
.bind(this)
113 this.enqueueTask
= this.enqueueTask
.bind(this)
114 this.checkAndEmitEvents
= this.checkAndEmitEvents
.bind(this)
116 if (this.opts
.enableEvents
=== true) {
117 this.emitter
= new PoolEmitter()
119 this.workerChoiceStrategyContext
= new WorkerChoiceStrategyContext
<
125 this.opts
.workerChoiceStrategy
,
126 this.opts
.workerChoiceStrategyOptions
131 while (this.workerNodes
.length
< this.numberOfWorkers
) {
132 this.createAndSetupWorker()
135 this.startTimestamp
= performance
.now()
138 private checkFilePath (filePath
: string): void {
141 typeof filePath
!== 'string' ||
142 (typeof filePath
=== 'string' && filePath
.trim().length
=== 0)
144 throw new Error('Please specify a file with a worker implementation')
146 if (!existsSync(filePath
)) {
147 throw new Error(`Cannot find the worker file '${filePath}'`)
151 private checkNumberOfWorkers (numberOfWorkers
: number): void {
152 if (numberOfWorkers
== null) {
154 'Cannot instantiate a pool without specifying the number of workers'
156 } else if (!Number.isSafeInteger(numberOfWorkers
)) {
158 'Cannot instantiate a pool with a non safe integer number of workers'
160 } else if (numberOfWorkers
< 0) {
161 throw new RangeError(
162 'Cannot instantiate a pool with a negative number of workers'
164 } else if (this.type === PoolTypes
.fixed
&& numberOfWorkers
=== 0) {
165 throw new RangeError('Cannot instantiate a fixed pool with zero worker')
169 protected checkDynamicPoolSize (min
: number, max
: number): void {
170 if (this.type === PoolTypes
.dynamic
) {
172 throw new RangeError(
173 'Cannot instantiate a dynamic pool with a maximum pool size inferior to the minimum pool size'
175 } else if (min
=== 0 && max
=== 0) {
176 throw new RangeError(
177 'Cannot instantiate a dynamic pool with a minimum pool size and a maximum pool size equal to zero'
179 } else if (min
=== max
) {
180 throw new RangeError(
181 'Cannot instantiate a dynamic pool with a minimum pool size equal to the maximum pool size. Use a fixed pool instead'
187 private checkPoolOptions (opts
: PoolOptions
<Worker
>): void {
188 if (isPlainObject(opts
)) {
189 this.opts
.workerChoiceStrategy
=
190 opts
.workerChoiceStrategy
?? WorkerChoiceStrategies
.ROUND_ROBIN
191 this.checkValidWorkerChoiceStrategy(this.opts
.workerChoiceStrategy
)
192 this.opts
.workerChoiceStrategyOptions
=
193 opts
.workerChoiceStrategyOptions
??
194 DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
195 this.checkValidWorkerChoiceStrategyOptions(
196 this.opts
.workerChoiceStrategyOptions
198 this.opts
.restartWorkerOnError
= opts
.restartWorkerOnError
?? true
199 this.opts
.enableEvents
= opts
.enableEvents
?? true
200 this.opts
.enableTasksQueue
= opts
.enableTasksQueue
?? false
201 if (this.opts
.enableTasksQueue
) {
202 this.checkValidTasksQueueOptions(
203 opts
.tasksQueueOptions
as TasksQueueOptions
205 this.opts
.tasksQueueOptions
= this.buildTasksQueueOptions(
206 opts
.tasksQueueOptions
as TasksQueueOptions
210 throw new TypeError('Invalid pool options: must be a plain object')
214 private checkValidWorkerChoiceStrategy (
215 workerChoiceStrategy
: WorkerChoiceStrategy
217 if (!Object.values(WorkerChoiceStrategies
).includes(workerChoiceStrategy
)) {
219 `Invalid worker choice strategy '${workerChoiceStrategy}'`
224 private checkValidWorkerChoiceStrategyOptions (
225 workerChoiceStrategyOptions
: WorkerChoiceStrategyOptions
227 if (!isPlainObject(workerChoiceStrategyOptions
)) {
229 'Invalid worker choice strategy options: must be a plain object'
233 workerChoiceStrategyOptions
.weights
!= null &&
234 Object.keys(workerChoiceStrategyOptions
.weights
).length
!== this.maxSize
237 'Invalid worker choice strategy options: must have a weight for each worker node'
241 workerChoiceStrategyOptions
.measurement
!= null &&
242 !Object.values(Measurements
).includes(
243 workerChoiceStrategyOptions
.measurement
247 `Invalid worker choice strategy options: invalid measurement '${workerChoiceStrategyOptions.measurement}'`
252 private checkValidTasksQueueOptions (
253 tasksQueueOptions
: TasksQueueOptions
255 if (tasksQueueOptions
!= null && !isPlainObject(tasksQueueOptions
)) {
256 throw new TypeError('Invalid tasks queue options: must be a plain object')
259 tasksQueueOptions
?.concurrency
!= null &&
260 !Number.isSafeInteger(tasksQueueOptions
.concurrency
)
263 'Invalid worker tasks concurrency: must be an integer'
267 tasksQueueOptions
?.concurrency
!= null &&
268 tasksQueueOptions
.concurrency
<= 0
271 `Invalid worker tasks concurrency '${tasksQueueOptions.concurrency}'`
277 public get
info (): PoolInfo
{
283 strategy
: this.opts
.workerChoiceStrategy
as WorkerChoiceStrategy
,
284 minSize
: this.minSize
,
285 maxSize
: this.maxSize
,
286 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
287 .runTime
.aggregate
&&
288 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
289 .waitTime
.aggregate
&& { utilization
: round(this.utilization
) }),
290 workerNodes
: this.workerNodes
.length
,
291 idleWorkerNodes
: this.workerNodes
.reduce(
292 (accumulator
, workerNode
) =>
293 workerNode
.usage
.tasks
.executing
=== 0
298 busyWorkerNodes
: this.workerNodes
.reduce(
299 (accumulator
, workerNode
) =>
300 workerNode
.usage
.tasks
.executing
> 0 ? accumulator
+ 1 : accumulator
,
303 executedTasks
: this.workerNodes
.reduce(
304 (accumulator
, workerNode
) =>
305 accumulator
+ workerNode
.usage
.tasks
.executed
,
308 executingTasks
: this.workerNodes
.reduce(
309 (accumulator
, workerNode
) =>
310 accumulator
+ workerNode
.usage
.tasks
.executing
,
313 queuedTasks
: this.workerNodes
.reduce(
314 (accumulator
, workerNode
) =>
315 accumulator
+ workerNode
.usage
.tasks
.queued
,
318 maxQueuedTasks
: this.workerNodes
.reduce(
319 (accumulator
, workerNode
) =>
320 accumulator
+ (workerNode
.usage
.tasks
?.maxQueued
?? 0),
323 failedTasks
: this.workerNodes
.reduce(
324 (accumulator
, workerNode
) =>
325 accumulator
+ workerNode
.usage
.tasks
.failed
,
328 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
329 .runTime
.aggregate
&& {
333 ...this.workerNodes
.map(
334 workerNode
=> workerNode
.usage
.runTime
?.minimum
?? Infinity
340 ...this.workerNodes
.map(
341 workerNode
=> workerNode
.usage
.runTime
?.maximum
?? -Infinity
346 this.workerNodes
.reduce(
347 (accumulator
, workerNode
) =>
348 accumulator
+ (workerNode
.usage
.runTime
?.aggregate
?? 0),
351 this.workerNodes
.reduce(
352 (accumulator
, workerNode
) =>
353 accumulator
+ (workerNode
.usage
.tasks
?.executed
?? 0),
357 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
361 this.workerNodes
.map(
362 workerNode
=> workerNode
.usage
.runTime
?.median
?? 0
369 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
370 .waitTime
.aggregate
&& {
374 ...this.workerNodes
.map(
375 workerNode
=> workerNode
.usage
.waitTime
?.minimum
?? Infinity
381 ...this.workerNodes
.map(
382 workerNode
=> workerNode
.usage
.waitTime
?.maximum
?? -Infinity
387 this.workerNodes
.reduce(
388 (accumulator
, workerNode
) =>
389 accumulator
+ (workerNode
.usage
.waitTime
?.aggregate
?? 0),
392 this.workerNodes
.reduce(
393 (accumulator
, workerNode
) =>
394 accumulator
+ (workerNode
.usage
.tasks
?.executed
?? 0),
398 ...(this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
399 .waitTime
.median
&& {
402 this.workerNodes
.map(
403 workerNode
=> workerNode
.usage
.waitTime
?.median
?? 0
413 private get
starting (): boolean {
415 this.workerNodes
.length
< this.minSize
||
416 (this.workerNodes
.length
>= this.minSize
&&
417 this.workerNodes
.some(workerNode
=> !workerNode
.info
.ready
))
421 private get
ready (): boolean {
423 this.workerNodes
.length
>= this.minSize
&&
424 this.workerNodes
.every(workerNode
=> workerNode
.info
.ready
)
429 * Gets the approximate pool utilization.
431 * @returns The pool utilization.
433 private get
utilization (): number {
434 const poolTimeCapacity
=
435 (performance
.now() - this.startTimestamp
) * this.maxSize
436 const totalTasksRunTime
= this.workerNodes
.reduce(
437 (accumulator
, workerNode
) =>
438 accumulator
+ (workerNode
.usage
.runTime
?.aggregate
?? 0),
441 const totalTasksWaitTime
= this.workerNodes
.reduce(
442 (accumulator
, workerNode
) =>
443 accumulator
+ (workerNode
.usage
.waitTime
?.aggregate
?? 0),
446 return (totalTasksRunTime
+ totalTasksWaitTime
) / poolTimeCapacity
452 * If it is `'dynamic'`, it provides the `max` property.
454 protected abstract get
type (): PoolType
457 * Gets the worker type.
459 protected abstract get
worker (): WorkerType
464 protected abstract get
minSize (): number
469 protected abstract get
maxSize (): number
472 * Get the worker given its id.
474 * @param workerId - The worker id.
475 * @returns The worker if found in the pool worker nodes, `undefined` otherwise.
477 private getWorkerById (workerId
: number): Worker
| undefined {
478 return this.workerNodes
.find(workerNode
=> workerNode
.info
.id
=== workerId
)
483 * Checks if the worker id sent in the received message from a worker is valid.
485 * @param message - The received message.
486 * @throws {@link https://nodejs.org/api/errors.html#class-error} If the worker id is invalid.
488 private checkMessageWorkerId (message
: MessageValue
<Response
>): void {
490 message
.workerId
!= null &&
491 this.getWorkerById(message
.workerId
) == null
494 `Worker message received from unknown worker '${message.workerId}'`
500 * Gets the given worker its worker node key.
502 * @param worker - The worker.
503 * @returns The worker node key if found in the pool worker nodes, `-1` otherwise.
505 private getWorkerNodeKey (worker
: Worker
): number {
506 return this.workerNodes
.findIndex(
507 workerNode
=> workerNode
.worker
=== worker
512 public setWorkerChoiceStrategy (
513 workerChoiceStrategy
: WorkerChoiceStrategy
,
514 workerChoiceStrategyOptions
?: WorkerChoiceStrategyOptions
516 this.checkValidWorkerChoiceStrategy(workerChoiceStrategy
)
517 this.opts
.workerChoiceStrategy
= workerChoiceStrategy
518 this.workerChoiceStrategyContext
.setWorkerChoiceStrategy(
519 this.opts
.workerChoiceStrategy
521 if (workerChoiceStrategyOptions
!= null) {
522 this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions
)
524 for (const workerNode
of this.workerNodes
) {
525 workerNode
.resetUsage()
526 this.setWorkerStatistics(workerNode
.worker
)
531 public setWorkerChoiceStrategyOptions (
532 workerChoiceStrategyOptions
: WorkerChoiceStrategyOptions
534 this.checkValidWorkerChoiceStrategyOptions(workerChoiceStrategyOptions
)
535 this.opts
.workerChoiceStrategyOptions
= workerChoiceStrategyOptions
536 this.workerChoiceStrategyContext
.setOptions(
537 this.opts
.workerChoiceStrategyOptions
542 public enableTasksQueue (
544 tasksQueueOptions
?: TasksQueueOptions
546 if (this.opts
.enableTasksQueue
=== true && !enable
) {
547 this.flushTasksQueues()
549 this.opts
.enableTasksQueue
= enable
550 this.setTasksQueueOptions(tasksQueueOptions
as TasksQueueOptions
)
554 public setTasksQueueOptions (tasksQueueOptions
: TasksQueueOptions
): void {
555 if (this.opts
.enableTasksQueue
=== true) {
556 this.checkValidTasksQueueOptions(tasksQueueOptions
)
557 this.opts
.tasksQueueOptions
=
558 this.buildTasksQueueOptions(tasksQueueOptions
)
559 } else if (this.opts
.tasksQueueOptions
!= null) {
560 delete this.opts
.tasksQueueOptions
564 private buildTasksQueueOptions (
565 tasksQueueOptions
: TasksQueueOptions
566 ): TasksQueueOptions
{
568 concurrency
: tasksQueueOptions
?.concurrency
?? 1
573 * Whether the pool is full or not.
575 * The pool filling boolean status.
577 protected get
full (): boolean {
578 return this.workerNodes
.length
>= this.maxSize
582 * Whether the pool is busy or not.
584 * The pool busyness boolean status.
586 protected abstract get
busy (): boolean
589 * Whether worker nodes are executing at least one task.
591 * @returns Worker nodes busyness boolean status.
593 protected internalBusy (): boolean {
595 this.workerNodes
.findIndex(workerNode
=> {
596 return workerNode
.usage
.tasks
.executing
=== 0
602 public async execute (data
?: Data
, name
?: string): Promise
<Response
> {
603 const timestamp
= performance
.now()
604 const workerNodeKey
= this.chooseWorkerNode()
605 const submittedTask
: Task
<Data
> = {
606 name
: name
?? DEFAULT_TASK_NAME
,
607 // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
608 data
: data
?? ({} as Data
),
610 workerId
: this.getWorkerInfo(workerNodeKey
).id
as number,
613 const res
= new Promise
<Response
>((resolve
, reject
) => {
614 this.promiseResponseMap
.set(submittedTask
.id
as string, {
617 worker
: this.workerNodes
[workerNodeKey
].worker
621 this.opts
.enableTasksQueue
=== true &&
623 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
>=
624 ((this.opts
.tasksQueueOptions
as TasksQueueOptions
)
625 .concurrency
as number))
627 this.enqueueTask(workerNodeKey
, submittedTask
)
629 this.executeTask(workerNodeKey
, submittedTask
)
631 this.checkAndEmitEvents()
632 // eslint-disable-next-line @typescript-eslint/return-await
637 public async destroy (): Promise
<void> {
639 this.workerNodes
.map(async (workerNode
, workerNodeKey
) => {
640 this.flushTasksQueue(workerNodeKey
)
641 // FIXME: wait for tasks to be finished
642 const workerExitPromise
= new Promise
<void>(resolve
=> {
643 workerNode
.worker
.on('exit', () => {
647 await this.destroyWorker(workerNode
.worker
)
648 await workerExitPromise
654 * Terminates the given worker.
656 * @param worker - A worker within `workerNodes`.
658 protected abstract destroyWorker (worker
: Worker
): void | Promise
<void>
661 * Setup hook to execute code before worker nodes are created in the abstract constructor.
666 protected setupHook (): void {
667 // Intentionally empty
671 * Should return whether the worker is the main worker or not.
673 protected abstract isMain (): boolean
676 * Hook executed before the worker task execution.
679 * @param workerNodeKey - The worker node key.
680 * @param task - The task to execute.
682 protected beforeTaskExecutionHook (
683 workerNodeKey
: number,
686 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
687 ++workerUsage
.tasks
.executing
688 this.updateWaitTimeWorkerUsage(workerUsage
, task
)
689 const taskWorkerUsage
= this.workerNodes
[workerNodeKey
].getTaskWorkerUsage(
692 ++taskWorkerUsage
.tasks
.executing
693 this.updateWaitTimeWorkerUsage(taskWorkerUsage
, task
)
697 * Hook executed after the worker task execution.
700 * @param worker - The worker.
701 * @param message - The received message.
703 protected afterTaskExecutionHook (
705 message
: MessageValue
<Response
>
707 const workerNodeKey
= this.getWorkerNodeKey(worker
)
708 const workerUsage
= this.workerNodes
[workerNodeKey
].usage
709 this.updateTaskStatisticsWorkerUsage(workerUsage
, message
)
710 this.updateRunTimeWorkerUsage(workerUsage
, message
)
711 this.updateEluWorkerUsage(workerUsage
, message
)
712 const taskWorkerUsage
= this.workerNodes
[workerNodeKey
].getTaskWorkerUsage(
713 message
.taskPerformance
?.name
?? DEFAULT_TASK_NAME
715 this.updateTaskStatisticsWorkerUsage(taskWorkerUsage
, message
)
716 this.updateRunTimeWorkerUsage(taskWorkerUsage
, message
)
717 this.updateEluWorkerUsage(taskWorkerUsage
, message
)
720 private updateTaskStatisticsWorkerUsage (
721 workerUsage
: WorkerUsage
,
722 message
: MessageValue
<Response
>
724 const workerTaskStatistics
= workerUsage
.tasks
725 --workerTaskStatistics
.executing
726 if (message
.taskError
== null) {
727 ++workerTaskStatistics
.executed
729 ++workerTaskStatistics
.failed
733 private updateRunTimeWorkerUsage (
734 workerUsage
: WorkerUsage
,
735 message
: MessageValue
<Response
>
738 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements().runTime
741 const taskRunTime
= message
.taskPerformance
?.runTime
?? 0
742 workerUsage
.runTime
.aggregate
=
743 (workerUsage
.runTime
.aggregate
?? 0) + taskRunTime
744 workerUsage
.runTime
.minimum
= Math.min(
746 workerUsage
.runTime
?.minimum
?? Infinity
748 workerUsage
.runTime
.maximum
= Math.max(
750 workerUsage
.runTime
?.maximum
?? -Infinity
753 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements().runTime
755 workerUsage
.tasks
.executed
!== 0
757 workerUsage
.runTime
.average
=
758 workerUsage
.runTime
.aggregate
/ workerUsage
.tasks
.executed
761 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements().runTime
763 message
.taskPerformance
?.runTime
!= null
765 workerUsage
.runTime
.history
.push(message
.taskPerformance
.runTime
)
766 workerUsage
.runTime
.median
= median(workerUsage
.runTime
.history
)
771 private updateWaitTimeWorkerUsage (
772 workerUsage
: WorkerUsage
,
775 const timestamp
= performance
.now()
776 const taskWaitTime
= timestamp
- (task
.timestamp
?? timestamp
)
778 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements().waitTime
781 workerUsage
.waitTime
.aggregate
=
782 (workerUsage
.waitTime
?.aggregate
?? 0) + taskWaitTime
783 workerUsage
.waitTime
.minimum
= Math.min(
785 workerUsage
.waitTime
?.minimum
?? Infinity
787 workerUsage
.waitTime
.maximum
= Math.max(
789 workerUsage
.waitTime
?.maximum
?? -Infinity
792 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
794 workerUsage
.tasks
.executed
!== 0
796 workerUsage
.waitTime
.average
=
797 workerUsage
.waitTime
.aggregate
/ workerUsage
.tasks
.executed
800 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
803 workerUsage
.waitTime
.history
.push(taskWaitTime
)
804 workerUsage
.waitTime
.median
= median(workerUsage
.waitTime
.history
)
809 private updateEluWorkerUsage (
810 workerUsage
: WorkerUsage
,
811 message
: MessageValue
<Response
>
814 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements().elu
817 if (message
.taskPerformance
?.elu
!= null) {
818 workerUsage
.elu
.idle
.aggregate
=
819 (workerUsage
.elu
.idle
?.aggregate
?? 0) +
820 message
.taskPerformance
.elu
.idle
821 workerUsage
.elu
.active
.aggregate
=
822 (workerUsage
.elu
.active
?.aggregate
?? 0) +
823 message
.taskPerformance
.elu
.active
824 if (workerUsage
.elu
.utilization
!= null) {
825 workerUsage
.elu
.utilization
=
826 (workerUsage
.elu
.utilization
+
827 message
.taskPerformance
.elu
.utilization
) /
830 workerUsage
.elu
.utilization
= message
.taskPerformance
.elu
.utilization
832 workerUsage
.elu
.idle
.minimum
= Math.min(
833 message
.taskPerformance
.elu
.idle
,
834 workerUsage
.elu
.idle
?.minimum
?? Infinity
836 workerUsage
.elu
.idle
.maximum
= Math.max(
837 message
.taskPerformance
.elu
.idle
,
838 workerUsage
.elu
.idle
?.maximum
?? -Infinity
840 workerUsage
.elu
.active
.minimum
= Math.min(
841 message
.taskPerformance
.elu
.active
,
842 workerUsage
.elu
.active
?.minimum
?? Infinity
844 workerUsage
.elu
.active
.maximum
= Math.max(
845 message
.taskPerformance
.elu
.active
,
846 workerUsage
.elu
.active
?.maximum
?? -Infinity
849 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements().elu
851 workerUsage
.tasks
.executed
!== 0
853 workerUsage
.elu
.idle
.average
=
854 workerUsage
.elu
.idle
.aggregate
/ workerUsage
.tasks
.executed
855 workerUsage
.elu
.active
.average
=
856 workerUsage
.elu
.active
.aggregate
/ workerUsage
.tasks
.executed
859 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements().elu
862 workerUsage
.elu
.idle
.history
.push(message
.taskPerformance
.elu
.idle
)
863 workerUsage
.elu
.active
.history
.push(
864 message
.taskPerformance
.elu
.active
866 workerUsage
.elu
.idle
.median
= median(workerUsage
.elu
.idle
.history
)
867 workerUsage
.elu
.active
.median
= median(workerUsage
.elu
.active
.history
)
874 * Chooses a worker node for the next task.
876 * The default worker choice strategy uses a round robin algorithm to distribute the tasks.
878 * @returns The worker node key
880 private chooseWorkerNode (): number {
881 if (this.shallCreateDynamicWorker()) {
882 const worker
= this.createAndSetupDynamicWorker()
884 this.workerChoiceStrategyContext
.getStrategyPolicy().useDynamicWorker
886 return this.getWorkerNodeKey(worker
)
889 return this.workerChoiceStrategyContext
.execute()
893 * Conditions for dynamic worker creation.
895 * @returns Whether to create a dynamic worker or not.
897 private shallCreateDynamicWorker (): boolean {
898 return this.type === PoolTypes
.dynamic
&& !this.full
&& this.internalBusy()
902 * Sends a message to the given worker.
904 * @param worker - The worker which should receive the message.
905 * @param message - The message.
907 protected abstract sendToWorker (
909 message
: MessageValue
<Data
>
913 * Creates a new worker.
915 * @returns Newly created worker.
917 protected abstract createWorker (): Worker
920 * Creates a new worker and sets it up completely in the pool worker nodes.
922 * @returns New, completely set up worker.
924 protected createAndSetupWorker (): Worker
{
925 const worker
= this.createWorker()
927 worker
.on('message', this.opts
.messageHandler
?? EMPTY_FUNCTION
)
928 worker
.on('error', this.opts
.errorHandler
?? EMPTY_FUNCTION
)
929 worker
.on('error', error
=> {
930 const workerNodeKey
= this.getWorkerNodeKey(worker
)
931 const workerInfo
= this.getWorkerInfo(workerNodeKey
)
932 workerInfo
.ready
= false
933 if (this.emitter
!= null) {
934 this.emitter
.emit(PoolEvents
.error
, error
)
936 if (this.opts
.restartWorkerOnError
=== true && !this.starting
) {
937 if (workerInfo
.dynamic
) {
938 this.createAndSetupDynamicWorker()
940 this.createAndSetupWorker()
943 if (this.opts
.enableTasksQueue
=== true) {
944 this.redistributeQueuedTasks(workerNodeKey
)
947 worker
.on('online', this.opts
.onlineHandler
?? EMPTY_FUNCTION
)
948 worker
.on('exit', this.opts
.exitHandler
?? EMPTY_FUNCTION
)
949 worker
.once('exit', () => {
950 this.removeWorkerNode(worker
)
953 this.pushWorkerNode(worker
)
955 this.afterWorkerSetup(worker
)
961 * Creates a new dynamic worker and sets it up completely in the pool worker nodes.
963 * @returns New, completely set up dynamic worker.
965 protected createAndSetupDynamicWorker (): Worker
{
966 const worker
= this.createAndSetupWorker()
967 this.registerWorkerMessageListener(worker
, message
=> {
968 const workerNodeKey
= this.getWorkerNodeKey(worker
)
970 isKillBehavior(KillBehaviors
.HARD
, message
.kill
) ||
971 (message
.kill
!= null &&
972 ((this.opts
.enableTasksQueue
=== false &&
973 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
=== 0) ||
974 (this.opts
.enableTasksQueue
=== true &&
975 this.workerNodes
[workerNodeKey
].usage
.tasks
.executing
=== 0 &&
976 this.tasksQueueSize(workerNodeKey
) === 0)))
978 // Kill message received from the worker: no new tasks are submitted to that worker for a while ( > maxInactiveTime)
979 void (this.destroyWorker(worker
) as Promise
<void>)
982 const workerInfo
= this.getWorkerInfo(this.getWorkerNodeKey(worker
))
983 workerInfo
.dynamic
= true
984 this.sendToWorker(worker
, {
986 workerId
: workerInfo
.id
as number
992 * Registers a listener callback on the given worker.
994 * @param worker - The worker which should register a listener.
995 * @param listener - The message listener callback.
997 private registerWorkerMessageListener
<Message
extends Data
| Response
>(
999 listener
: (message
: MessageValue
<Message
>) => void
1001 worker
.on('message', listener
as MessageHandler
<Worker
>)
1005 * Function that can be hooked up when a worker has been newly created and moved to the pool worker nodes.
1006 * Can be overridden.
1008 * @param worker - The newly created worker.
1010 protected afterWorkerSetup (worker
: Worker
): void {
1011 // Listen to worker messages.
1012 this.registerWorkerMessageListener(worker
, this.workerListener())
1013 // Send startup message to worker.
1014 this.sendToWorker(worker
, {
1016 workerId
: this.getWorkerInfo(this.getWorkerNodeKey(worker
)).id
as number
1018 // Setup worker task statistics computation.
1019 this.setWorkerStatistics(worker
)
1022 private redistributeQueuedTasks (workerNodeKey
: number): void {
1023 while (this.tasksQueueSize(workerNodeKey
) > 0) {
1024 let targetWorkerNodeKey
: number = workerNodeKey
1025 let minQueuedTasks
= Infinity
1026 for (const [workerNodeId
, workerNode
] of this.workerNodes
.entries()) {
1027 const workerInfo
= this.getWorkerInfo(workerNodeId
)
1029 workerNodeId
!== workerNodeKey
&&
1031 workerNode
.usage
.tasks
.queued
=== 0
1033 targetWorkerNodeKey
= workerNodeId
1037 workerNodeId
!== workerNodeKey
&&
1039 workerNode
.usage
.tasks
.queued
< minQueuedTasks
1041 minQueuedTasks
= workerNode
.usage
.tasks
.queued
1042 targetWorkerNodeKey
= workerNodeId
1046 targetWorkerNodeKey
,
1047 this.dequeueTask(workerNodeKey
) as Task
<Data
>
1053 * This function is the listener registered for each worker message.
1055 * @returns The listener function to execute when a message is received from a worker.
1057 protected workerListener (): (message
: MessageValue
<Response
>) => void {
1059 this.checkMessageWorkerId(message
)
1060 if (message
.ready
!= null && message
.workerId
!= null) {
1061 // Worker ready message received
1062 this.handleWorkerReadyMessage(message
)
1063 } else if (message
.id
!= null) {
1064 // Task execution response received
1065 this.handleTaskExecutionResponse(message
)
1070 private handleWorkerReadyMessage (message
: MessageValue
<Response
>): void {
1071 const worker
= this.getWorkerById(message
.workerId
)
1072 this.getWorkerInfo(this.getWorkerNodeKey(worker
as Worker
)).ready
=
1073 message
.ready
as boolean
1074 if (this.emitter
!= null && this.ready
) {
1075 this.emitter
.emit(PoolEvents
.ready
, this.info
)
1079 private handleTaskExecutionResponse (message
: MessageValue
<Response
>): void {
1080 const promiseResponse
= this.promiseResponseMap
.get(message
.id
as string)
1081 if (promiseResponse
!= null) {
1082 if (message
.taskError
!= null) {
1083 if (this.emitter
!= null) {
1084 this.emitter
.emit(PoolEvents
.taskError
, message
.taskError
)
1086 promiseResponse
.reject(message
.taskError
.message
)
1088 promiseResponse
.resolve(message
.data
as Response
)
1090 this.afterTaskExecutionHook(promiseResponse
.worker
, message
)
1091 this.promiseResponseMap
.delete(message
.id
as string)
1092 const workerNodeKey
= this.getWorkerNodeKey(promiseResponse
.worker
)
1094 this.opts
.enableTasksQueue
=== true &&
1095 this.tasksQueueSize(workerNodeKey
) > 0
1099 this.dequeueTask(workerNodeKey
) as Task
<Data
>
1102 this.workerChoiceStrategyContext
.update(workerNodeKey
)
1106 private checkAndEmitEvents (): void {
1107 if (this.emitter
!= null) {
1109 this.emitter
.emit(PoolEvents
.busy
, this.info
)
1111 if (this.type === PoolTypes
.dynamic
&& this.full
) {
1112 this.emitter
.emit(PoolEvents
.full
, this.info
)
1118 * Gets the worker information.
1120 * @param workerNodeKey - The worker node key.
1122 private getWorkerInfo (workerNodeKey
: number): WorkerInfo
{
1123 return this.workerNodes
[workerNodeKey
].info
1127 * Pushes the given worker in the pool worker nodes.
1129 * @param worker - The worker.
1130 * @returns The worker nodes length.
1132 private pushWorkerNode (worker
: Worker
): number {
1133 return this.workerNodes
.push(new WorkerNode(worker
, this.worker
))
1137 * Removes the given worker from the pool worker nodes.
1139 * @param worker - The worker.
1141 private removeWorkerNode (worker
: Worker
): void {
1142 const workerNodeKey
= this.getWorkerNodeKey(worker
)
1143 if (workerNodeKey
!== -1) {
1144 this.workerNodes
.splice(workerNodeKey
, 1)
1145 this.workerChoiceStrategyContext
.remove(workerNodeKey
)
1149 private executeTask (workerNodeKey
: number, task
: Task
<Data
>): void {
1150 this.beforeTaskExecutionHook(workerNodeKey
, task
)
1151 this.sendToWorker(this.workerNodes
[workerNodeKey
].worker
, task
)
1154 private enqueueTask (workerNodeKey
: number, task
: Task
<Data
>): number {
1155 return this.workerNodes
[workerNodeKey
].enqueueTask(task
)
1158 private dequeueTask (workerNodeKey
: number): Task
<Data
> | undefined {
1159 return this.workerNodes
[workerNodeKey
].dequeueTask()
1162 private tasksQueueSize (workerNodeKey
: number): number {
1163 return this.workerNodes
[workerNodeKey
].tasksQueueSize()
1166 private flushTasksQueue (workerNodeKey
: number): void {
1167 while (this.tasksQueueSize(workerNodeKey
) > 0) {
1170 this.dequeueTask(workerNodeKey
) as Task
<Data
>
1173 this.workerNodes
[workerNodeKey
].clearTasksQueue()
1176 private flushTasksQueues (): void {
1177 for (const [workerNodeKey
] of this.workerNodes
.entries()) {
1178 this.flushTasksQueue(workerNodeKey
)
1182 private setWorkerStatistics (worker
: Worker
): void {
1183 this.sendToWorker(worker
, {
1186 this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
1188 elu
: this.workerChoiceStrategyContext
.getTaskStatisticsRequirements()
1191 workerId
: this.getWorkerInfo(this.getWorkerNodeKey(worker
)).id
as number