3 All notable changes to this project will be documented in this file.
5 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
6 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
12 - Fix pool `execute()` arguments check.
16 - Make continuous tasks stealing algorithm less aggressive.
17 - Fine tune tasks stealing algorithm under back pressure.
19 ## [2.6.35] - 2023-08-25
23 - Don't account worker usage statistics for tasks that have failed.
24 - Fix pool information runtime and wait time median computation.
28 - Update simple moving average implementation to use a circular buffer.
29 - Update simple moving median implementation to use a circular buffer.
30 - Account for stolen tasks in worker usage statistics and pool information.
34 - Continuous tasks stealing algorithm.
36 ## [2.6.34] - 2023-08-24
40 - Avoid cascading tasks stealing under back pressure.
44 - Add fastpath to queued tasks rescheduling.
46 ## [2.6.33] - 2023-08-24
50 - Fix queued tasks rescheduling.
54 - Rename tasks queue options `queueMaxSize` to `size`.
58 - Task stealing scheduling algorithm if tasks queueing is enabled.
60 ## [2.6.32] - 2023-08-23
64 - Ensure no task can be executed when the pool is destroyed.
68 - Add `queueMaxSize` option to tasks queue options.
69 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
70 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
72 ## [2.6.31] - 2023-08-20
76 - Fix worker choice strategy retries mechanism in some edge cases.
80 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
81 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
83 ## [2.6.30] - 2023-08-19
87 - Ensure pool event `backPressure` is emitted.
88 - Ensure pool event `full` is emitted only once.
89 - Ensure worker node cannot be instantiated without proper arguments.
91 ## [2.6.29] - 2023-08-18
95 - Fix race condition between ready and task functions worker message handling at startup.
96 - Fix duplicate task function worker usage statistics computation per task function.
97 - Update task function worker usage statistics if and only if there's at least two different task functions.
98 - Fix race condition at task function worker usage executing task computation leading to negative value.
102 - Add back pressure detection on the worker node queue. Event `backPressure` is emitted when all worker node queues are full (worker node queue size >= poolMaxSize^2).
103 - Use back pressure detection in worker choice strategies.
104 - Add worker choice strategies retries mechanism if no worker is eligible.
106 ## [2.6.28] - 2023-08-16
110 - Ensure pool workers are properly initialized.
114 - HTTP server pool examples: express-cluster, express-hybrid.
118 - Remove now useless branching in worker hot code path.
120 ## [2.6.27] - 2023-08-15
124 - Add `KillHandler` type definition to exported types.
128 - Add `destroy` event to pool API.
130 ## [2.6.26] - 2023-08-15
134 - Add kill handler to worker options allowing to execute custom code when worker is killed.
135 - Add `listTaskFunctions()` method to pool API.
136 - SMTP server pool example: nodemailer.
138 ## [2.6.25] - 2023-08-13
142 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
143 - WebSocket server pool examples: ws-cluster, ws-hybrid.
145 ## [2.6.24] - 2023-08-12
149 - Add array of transferable objects to the `execute()` method arguments.
150 - WebSocket server pool examples: ws-worker_threads.
152 ## [2.6.23] - 2023-08-11
156 - Fix pool busyness semantic when tasks queueing is enabled: the pool is busy when the number of executing tasks on each worker has reached the maximum tasks concurrency per worker.
160 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
161 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
163 ## [2.6.22] - 2023-08-10
167 - Add missing `types` field to package.json `exports`.
171 - Structure markdown documentation (PR #811).
173 ## [2.6.21] - 2023-08-03
177 - Improve code documentation.
178 - Code refactoring and cleanup for better maintainability and readability.
180 ## [2.6.20] - 2023-07-21
184 - Fix queued tasks redistribution on error task execution starvation.
185 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
189 - Drastically reduce lookups by worker in the worker nodes.
191 ## [2.6.19] - 2023-07-20
195 - Dedicated internal communication channel for worker_threads pools.
197 ## [2.6.18] - 2023-07-19
201 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
203 ## [2.6.17] - 2023-07-16
207 - Add `listTaskFunctions()` method to worker API.
209 ## [2.6.16] - 2023-07-12
213 - Fix pool startup detection.
214 - Fix worker task functions handling.
216 ## [2.6.15] - 2023-07-11
220 - Take into account worker node readiness in worker choice strategies.
222 ## [2.6.14] - 2023-07-10
226 - Fix task function statistics tracking.
228 ## [2.6.13] - 2023-07-10
232 - Add per task function statistics tracking.
233 - Add public methods to manipulate the worker task functions at runtime.
235 ## [2.6.12] - 2023-07-09
239 - Workaround import issue with `node:os` module in node 16.x.x.
241 ## [2.6.11] - 2023-07-09
245 - Fix pool readiness semantic.
247 ## [2.6.10] - 2023-07-08
251 - Ensure workers are not recreated on error at pool startup.
255 - Add `ready` and `strategy` fields to pool information.
256 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
257 - Add dynamic pool sizing checks.
259 ## [2.6.9] - 2023-07-07
263 - Recreate the right worker type on uncaught exception.
267 - Add minimum and maximum to internal measurement statistics.
268 - Add `runTime` and `waitTime` to pool information.
269 - Check worker inactive time only on dynamic worker.
271 ## [2.6.8] - 2023-07-03
275 - Brown paper bag release to fix version handling in pool information.
277 ## [2.6.7] - 2023-07-03
281 - Ensure worker queued tasks at error are reassigned to other pool workers.
285 - Add pool `utilization` ratio to pool information.
286 - Add `version` to pool information.
287 - Add worker information to worker nodes.
289 ## [2.6.6] - 2023-07-01
293 - Add safe helper `availableParallelism()` to help sizing the pool.
297 - Ensure message handler is only registered in worker.
299 ## [2.6.5] - 2023-06-27
303 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
307 - Artificial version bump to 2.6.5 to workaround publication issue.
308 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
309 - Ensure pool event is emitted before task error promise rejection.
310 - Fix queued tasks count computation.
314 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
316 ## [2.6.4] - 2023-06-27
320 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
324 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
325 - Ensure pool event is emitted before task error promise rejection.
326 - Fix queued tasks count computation.
330 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
332 ## [2.6.3] - 2023-06-19
336 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
337 - Update strategies internals after statistics computation.
341 - Optimize O(1) queue implementation.
343 ## [2.6.2] - 2023-06-12
347 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
349 ## [2.6.1] - 2023-06-10
353 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
357 - Fix average statistics computation: ensure failed tasks are not accounted.
359 ## [2.6.0] - 2023-06-09
363 - Add `LEAST_ELU` worker choice strategy (experimental).
364 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
368 - Refactor pool worker node usage internals.
369 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
370 - Breaking change: pool information `info` property object fields have been renamed.
374 - Fix wait time accounting.
375 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
376 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
378 ## [2.5.4] - 2023-06-07
382 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
386 - Compute statistics at the worker level only if needed.
387 - Add `worker_threads` options to thread pool options.
391 - Make the `LEAST_BUSY` strategy only relies on task runtime.
393 ## [2.5.3] - 2023-06-04
397 - Refine pool information content.
398 - Limit pool internals public exposure.
400 ## [2.5.2] - 2023-06-02
404 - Add `taskError` pool event for task execution error.
405 - Add pool information `info` property to pool.
406 - Emit pool information on `busy` and `full` pool events.
408 ## [2.5.1] - 2023-06-01
412 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
413 - Add `error` pool event for uncaught worker error.
415 ## [2.5.0] - 2023-05-31
419 - Switch pool event emitter to `EventEmitterAsyncResource`.
420 - Add tasks wait time accounting in per worker tasks usage.
421 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
425 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
427 ## [2.4.14] - 2023-05-09
431 - Ensure no undefined task runtime can land in the tasks history.
432 - Fix median computation implementation once again.
436 - Unit tests for median and queue implementations.
438 ## [2.4.13] - 2023-05-08
442 - Fix worker choice strategy options validation.
443 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
445 ## [2.4.12] - 2023-05-06
449 - Support multiple task functions per worker.
450 - Add custom worker weights support to worker choice strategies options.
454 - Use O(1) queue implementation for tasks queueing.
458 - Fix median computation implementation.
459 - Fix fair share worker choice strategy internals update.
461 ## [2.4.11] - 2023-04-23
465 - Optimize free worker finding in worker choice strategies.
467 ## [2.4.10] - 2023-04-15
471 - Fix typescript type definition for task function: ensure the input data is optional.
472 - Fix typescript type definition for pool execute(): ensure the input data is optional.
474 ## [2.4.9] - 2023-04-15
478 - Add tasks queue enablement runtime setter to pool.
479 - Add tasks queue options runtime setter to pool.
480 - Add worker choice strategy options runtime setter to pool.
484 - Remove the tasks queuing experimental status.
488 - Fix task function type definition and validation.
489 - Fix worker choice strategy options handling.
491 ## [2.4.8] - 2023-04-12
495 - Fix message between main worker and worker type definition for tasks.
496 - Fix code documentation.
498 ## [2.4.7] - 2023-04-11
502 - Add worker tasks queue options to pool options.
506 - Fix missing documentation.
508 ## [2.4.6] - 2023-04-10
512 - Ensure one task at a time is executed per worker with tasks queueing enabled.
513 - Properly count worker executing tasks with tasks queueing enabled.
515 ## [2.4.5] - 2023-04-09
519 - Use monotonic high resolution timer for worker tasks runtime.
520 - Add worker tasks median runtime to statistics.
521 - Add worker tasks queue (experimental).
523 ## [2.4.4] - 2023-04-07
527 - Add `PoolEvents` enumeration and `PoolEvent` type.
531 - Destroy worker only on alive check.
533 ## [2.4.3] - 2023-04-07
537 - Fix typedoc generation with inheritance.
539 ## [2.4.2] - 2023-04-06
543 - Add `full` event to dynamic pool.
544 - Keep worker choice strategy in memory for conditional reuse.
548 - Fix possible negative worker key at worker removal in worker choice strategies.
550 ## [2.4.1] - 2023-04-05
554 - Optimize worker choice strategy for dynamic pool.
558 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
560 ## [2.4.0] - 2023-04-04
564 - Add `LESS_BUSY` worker choice strategy.
568 - Optimize worker storage in pool.
569 - Optimize worker alive status check.
570 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
571 - Optimize `LESS_USED` worker choice strategy.
572 - Update benchmarks versus external threads pools.
573 - Optimize tasks usage statistics requirements for worker choice strategy.
577 - Ensure trimmable characters are checked at pool initialization.
578 - Fix message id integer overflow.
579 - Fix pool worker removal in worker choice strategy internals.
580 - Fix package publication with pnpm.
582 ## [2.4.0-3] - 2023-04-04
586 - Add `LESS_BUSY` worker choice strategy.
590 - Optimize worker storage in pool.
591 - Optimize worker alive status check.
592 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
593 - Optimize `LESS_USED` worker choice strategy.
594 - Update benchmarks versus external threads pools.
598 - Ensure trimmable characters are checked at pool initialization.
599 - Fix message id integer overflow.
600 - Fix pool worker removal in worker choice strategy internals.
601 - Fix package publication with pnpm.
603 ## [2.4.0-2] - 2023-04-03
607 - Add `LESS_BUSY` worker choice strategy.
611 - Optimize worker storage in pool.
612 - Optimize worker alive status check.
613 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
614 - Optimize `LESS_USED` worker choice strategy.
618 - Ensure trimmable characters are checked at pool initialization.
619 - Fix message id integer overflow.
620 - Fix pool worker removal in worker choice strategy internals.
621 - Fix package publication with pnpm.
623 ## [2.4.0-1] - 2023-04-03
627 - Add `LESS_BUSY` worker choice strategy.
631 - Optimize worker storage in pool.
632 - Optimize worker alive status check.
633 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
634 - Optimize `LESS_USED` worker choice strategy.
638 - Ensure trimmable characters are checked at pool initialization.
639 - Fix message id integer overflow.
640 - Fix pool worker removal in worker choice strategy internals.
642 ## [2.4.0-0] - 2023-04-03
646 - Add `LESS_BUSY` worker choice strategy.
650 - Optimize worker storage in pool.
651 - Optimize worker alive status check.
652 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
653 - Optimize `LESS_USED` worker choice strategy.
657 - Ensure trimmable characters are checked at pool initialization.
658 - Fix message id integer overflow.
659 - Fix pool worker removal in worker choice strategy internals.
661 ## [2.3.10] - 2023-03-18
665 - Fix package.json `exports` syntax for ESM and CommonJS.
669 - Permit SemVer pre-release publication.
671 ## [2.3.10-2] - 2023-03-18
675 - Fix package.json `exports` syntax for ESM and CommonJS.
677 ## [2.3.10-1] - 2023-03-18
681 - Permit SemVer pre-release publication.
683 ## [2.3.10-0] - 2023-03-18
687 - Fix package.json `exports` syntax for ESM and CommonJS.
689 ## [2.3.9] - 2023-03-18
693 - Introduce ESM module support along with CommonJS one.
697 - Fix brown paper bag bug referencing the same object literal.
699 ## [2.3.8] - 2023-03-18
703 - Switch internal benchmarking code to benny.
704 - Switch to TypeScript 5.x.x.
705 - Switch rollup bundler plugins to core ones.
706 - Switch to TSDoc syntax.
707 - Enforce conventional commits.
711 - Fix random integer generator.
712 - Fix worker choice strategy pool type identification at initialization.
714 ## [2.3.7] - 2022-10-23
718 - Switch to open collective FOSS project funding platform.
719 - Switch to ts-standard linter configuration on TypeScript code.
723 - Fixed missing async on pool execute method.
724 - Fixed typing in TypeScript example.
725 - Fixed types in unit tests.
727 ## [2.3.6] - 2022-10-22
731 - Cleanup pool attributes and methods.
732 - Refine error types thrown.
736 - Fix continuous integration build on windows.
737 - Fix code coverage reporting by using c8 instead of nyc.
739 ## [2.3.5] - 2022-10-21
743 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
744 - Optimize tasks usage lookup implementation.
748 - Fix missed pool event emitter type export.
749 - Fix typedoc documentation generation.
751 ## [2.3.4] - 2022-10-17
755 - Fully automate release process with release-it.
759 - Optimize fair share task scheduling algorithm implementation.
760 - Update benchmarks versus external pools results with latest version.
762 ## [2.3.3] - 2022-10-15
766 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
768 ## [2.3.2] - 2022-10-14
772 - Optimize fair share worker selection strategy implementation.
776 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
778 ## [2.3.1] - 2022-10-13
782 - Pool worker choice strategies:
783 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
784 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
786 ## [2.2.2] - 2022-10-09
790 - Fixed `README.md` file.
792 ## [2.2.1] - 2022-10-08
796 - Dynamic worker choice strategy change at runtime.
798 ## [2.2.0] - 2022-01-05
802 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
804 ## [2.1.0] - 2021-08-29
808 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
812 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
813 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
814 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
815 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
817 ## [2.0.2] - 2021-05-12
821 - Fix `busy` event emission on fixed pool type
823 ## [2.0.1] - 2021-03-16
827 - Check if pool options are properly set.
828 - `busy` event is emitted on all pool types.
830 ## [2.0.0] - 2021-03-01
834 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
838 - `FullPool` event is now renamed to `busy`.
839 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
840 _Find more details on our JSDoc._
842 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
844 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
846 ### Pool options types declaration merge
848 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
850 #### New `export` strategy
854 const DynamicThreadPool = require('poolifier/lib/dynamic')
856 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
859 But you should always prefer just using
862 const { DynamicThreadPool } = require('poolifier')
865 #### New type definitions for input data and response
867 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
868 _This is not a limitation by poolifier but Node.js._
870 #### Public property replacements
872 `numWorkers` property is now `numberOfWorkers`
874 #### Internal (protected) properties and methods renaming
876 These properties are not intended for end users
878 - `id` => `nextMessageId`
880 These methods are not intended for end users
882 - `_chooseWorker` => `chooseWorker`
883 - `_newWorker` => `createWorker`
884 - `_execute` => `internalExecute`
885 - `_chooseWorker` => `chooseWorker`
886 - `_checkAlive` => `checkAlive`
888 - `_runAsync` => `runAsync`
890 ## [1.1.0] - 2020-05-21
894 - ThreadWorker support async functions as option
895 - Various external library patches
897 ## [1.0.0] - 2020-01-24
901 - FixedThreadPool implementation
902 - DynamicThreadPool implementation
903 - WorkerThread implementation to improve developer experience