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).
10 ## [2.6.33] - 2023-08-24
14 - Fix queued tasks rescheduling.
18 - Rename tasks queue options `queueMaxSize` to `size`.
22 - Task stealing scheduling algorithm if tasks queueing is enabled.
24 ## [2.6.32] - 2023-08-23
28 - Ensure no task can be executed when the pool is destroyed.
32 - Add `queueMaxSize` option to tasks queue options.
33 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
34 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
36 ## [2.6.31] - 2023-08-20
40 - Fix worker choice strategy retries mechanism in some edge cases.
44 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
45 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
47 ## [2.6.30] - 2023-08-19
51 - Ensure pool event `backPressure` is emitted.
52 - Ensure pool event `full` is emitted only once.
53 - Ensure worker node cannot be instantiated without proper arguments.
55 ## [2.6.29] - 2023-08-18
59 - Fix race condition between ready and task functions worker message handling at startup.
60 - Fix duplicate task function worker usage statistics computation per task function.
61 - Update task function worker usage statistics if and only if there's at least two different task functions.
62 - Fix race condition at task function worker usage executing task computation leading to negative value.
66 - 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).
67 - Use back pressure detection in worker choice strategies.
68 - Add worker choice strategies retries mechanism if no worker is eligible.
70 ## [2.6.28] - 2023-08-16
74 - Ensure pool workers are properly initialized.
78 - HTTP server pool examples: express-cluster, express-hybrid.
82 - Remove now useless branching in worker hot code path.
84 ## [2.6.27] - 2023-08-15
88 - Add `KillHandler` type definition to exported types.
92 - Add `destroy` event to pool API.
94 ## [2.6.26] - 2023-08-15
98 - Add kill handler to worker options allowing to execute custom code when worker is killed.
99 - Add `listTaskFunctions()` method to pool API.
100 - SMTP server pool example: nodemailer.
102 ## [2.6.25] - 2023-08-13
106 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
107 - WebSocket server pool examples: ws-cluster, ws-hybrid.
109 ## [2.6.24] - 2023-08-12
113 - Add array of transferable objects to the `execute()` method arguments.
114 - WebSocket server pool examples: ws-worker_threads.
116 ## [2.6.23] - 2023-08-11
120 - 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.
124 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
125 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
127 ## [2.6.22] - 2023-08-10
131 - Add missing `types` field to package.json `exports`.
135 - Structure markdown documentation (PR #811).
137 ## [2.6.21] - 2023-08-03
141 - Improve code documentation.
142 - Code refactoring and cleanup for better maintainability and readability.
144 ## [2.6.20] - 2023-07-21
148 - Fix queued tasks redistribution on error task execution starvation.
149 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
153 - Drastically reduce lookups by worker in the worker nodes.
155 ## [2.6.19] - 2023-07-20
159 - Dedicated internal communication channel for worker_threads pools.
161 ## [2.6.18] - 2023-07-19
165 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
167 ## [2.6.17] - 2023-07-16
171 - Add `listTaskFunctions()` method to worker API.
173 ## [2.6.16] - 2023-07-12
177 - Fix pool startup detection.
178 - Fix worker task functions handling.
180 ## [2.6.15] - 2023-07-11
184 - Take into account worker node readiness in worker choice strategies.
186 ## [2.6.14] - 2023-07-10
190 - Fix task function statistics tracking.
192 ## [2.6.13] - 2023-07-10
196 - Add per task function statistics tracking.
197 - Add public methods to manipulate the worker task functions at runtime.
199 ## [2.6.12] - 2023-07-09
203 - Workaround import issue with `node:os` module in node 16.x.x.
205 ## [2.6.11] - 2023-07-09
209 - Fix pool readiness semantic.
211 ## [2.6.10] - 2023-07-08
215 - Ensure workers are not recreated on error at pool startup.
219 - Add `ready` and `strategy` fields to pool information.
220 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
221 - Add dynamic pool sizing checks.
223 ## [2.6.9] - 2023-07-07
227 - Recreate the right worker type on uncaught exception.
231 - Add minimum and maximum to internal measurement statistics.
232 - Add `runTime` and `waitTime` to pool information.
233 - Check worker inactive time only on dynamic worker.
235 ## [2.6.8] - 2023-07-03
239 - Brown paper bag release to fix version handling in pool information.
241 ## [2.6.7] - 2023-07-03
245 - Ensure worker queued tasks at error are reassigned to other pool workers.
249 - Add pool `utilization` ratio to pool information.
250 - Add `version` to pool information.
251 - Add worker information to worker nodes.
253 ## [2.6.6] - 2023-07-01
257 - Add safe helper `availableParallelism()` to help sizing the pool.
261 - Ensure message handler is only registered in worker.
263 ## [2.6.5] - 2023-06-27
267 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
271 - Artificial version bump to 2.6.5 to workaround publication issue.
272 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
273 - Ensure pool event is emitted before task error promise rejection.
274 - Fix queued tasks count computation.
278 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
280 ## [2.6.4] - 2023-06-27
284 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
288 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
289 - Ensure pool event is emitted before task error promise rejection.
290 - Fix queued tasks count computation.
294 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
296 ## [2.6.3] - 2023-06-19
300 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
301 - Update strategies internals after statistics computation.
305 - Optimize O(1) queue implementation.
307 ## [2.6.2] - 2023-06-12
311 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
313 ## [2.6.1] - 2023-06-10
317 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
321 - Fix average statistics computation: ensure failed tasks are not accounted.
323 ## [2.6.0] - 2023-06-09
327 - Add `LEAST_ELU` worker choice strategy (experimental).
328 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
332 - Refactor pool worker node usage internals.
333 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
334 - Breaking change: pool information `info` property object fields have been renamed.
338 - Fix wait time accounting.
339 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
340 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
342 ## [2.5.4] - 2023-06-07
346 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
350 - Compute statistics at the worker level only if needed.
351 - Add `worker_threads` options to thread pool options.
355 - Make the `LEAST_BUSY` strategy only relies on task runtime.
357 ## [2.5.3] - 2023-06-04
361 - Refine pool information content.
362 - Limit pool internals public exposure.
364 ## [2.5.2] - 2023-06-02
368 - Add `taskError` pool event for task execution error.
369 - Add pool information `info` property to pool.
370 - Emit pool information on `busy` and `full` pool events.
372 ## [2.5.1] - 2023-06-01
376 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
377 - Add `error` pool event for uncaught worker error.
379 ## [2.5.0] - 2023-05-31
383 - Switch pool event emitter to `EventEmitterAsyncResource`.
384 - Add tasks wait time accounting in per worker tasks usage.
385 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
389 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
391 ## [2.4.14] - 2023-05-09
395 - Ensure no undefined task runtime can land in the tasks history.
396 - Fix median computation implementation once again.
400 - Unit tests for median and queue implementations.
402 ## [2.4.13] - 2023-05-08
406 - Fix worker choice strategy options validation.
407 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
409 ## [2.4.12] - 2023-05-06
413 - Support multiple task functions per worker.
414 - Add custom worker weights support to worker choice strategies options.
418 - Use O(1) queue implementation for tasks queueing.
422 - Fix median computation implementation.
423 - Fix fair share worker choice strategy internals update.
425 ## [2.4.11] - 2023-04-23
429 - Optimize free worker finding in worker choice strategies.
431 ## [2.4.10] - 2023-04-15
435 - Fix typescript type definition for task function: ensure the input data is optional.
436 - Fix typescript type definition for pool execute(): ensure the input data is optional.
438 ## [2.4.9] - 2023-04-15
442 - Add tasks queue enablement runtime setter to pool.
443 - Add tasks queue options runtime setter to pool.
444 - Add worker choice strategy options runtime setter to pool.
448 - Remove the tasks queuing experimental status.
452 - Fix task function type definition and validation.
453 - Fix worker choice strategy options handling.
455 ## [2.4.8] - 2023-04-12
459 - Fix message between main worker and worker type definition for tasks.
460 - Fix code documentation.
462 ## [2.4.7] - 2023-04-11
466 - Add worker tasks queue options to pool options.
470 - Fix missing documentation.
472 ## [2.4.6] - 2023-04-10
476 - Ensure one task at a time is executed per worker with tasks queueing enabled.
477 - Properly count worker executing tasks with tasks queueing enabled.
479 ## [2.4.5] - 2023-04-09
483 - Use monotonic high resolution timer for worker tasks runtime.
484 - Add worker tasks median runtime to statistics.
485 - Add worker tasks queue (experimental).
487 ## [2.4.4] - 2023-04-07
491 - Add `PoolEvents` enumeration and `PoolEvent` type.
495 - Destroy worker only on alive check.
497 ## [2.4.3] - 2023-04-07
501 - Fix typedoc generation with inheritance.
503 ## [2.4.2] - 2023-04-06
507 - Add `full` event to dynamic pool.
508 - Keep worker choice strategy in memory for conditional reuse.
512 - Fix possible negative worker key at worker removal in worker choice strategies.
514 ## [2.4.1] - 2023-04-05
518 - Optimize worker choice strategy for dynamic pool.
522 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
524 ## [2.4.0] - 2023-04-04
528 - Add `LESS_BUSY` worker choice strategy.
532 - Optimize worker storage in pool.
533 - Optimize worker alive status check.
534 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
535 - Optimize `LESS_USED` worker choice strategy.
536 - Update benchmarks versus external threads pools.
537 - Optimize tasks usage statistics requirements for worker choice strategy.
541 - Ensure trimmable characters are checked at pool initialization.
542 - Fix message id integer overflow.
543 - Fix pool worker removal in worker choice strategy internals.
544 - Fix package publication with pnpm.
546 ## [2.4.0-3] - 2023-04-04
550 - Add `LESS_BUSY` worker choice strategy.
554 - Optimize worker storage in pool.
555 - Optimize worker alive status check.
556 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
557 - Optimize `LESS_USED` worker choice strategy.
558 - Update benchmarks versus external threads pools.
562 - Ensure trimmable characters are checked at pool initialization.
563 - Fix message id integer overflow.
564 - Fix pool worker removal in worker choice strategy internals.
565 - Fix package publication with pnpm.
567 ## [2.4.0-2] - 2023-04-03
571 - Add `LESS_BUSY` worker choice strategy.
575 - Optimize worker storage in pool.
576 - Optimize worker alive status check.
577 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
578 - Optimize `LESS_USED` worker choice strategy.
582 - Ensure trimmable characters are checked at pool initialization.
583 - Fix message id integer overflow.
584 - Fix pool worker removal in worker choice strategy internals.
585 - Fix package publication with pnpm.
587 ## [2.4.0-1] - 2023-04-03
591 - Add `LESS_BUSY` worker choice strategy.
595 - Optimize worker storage in pool.
596 - Optimize worker alive status check.
597 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
598 - Optimize `LESS_USED` worker choice strategy.
602 - Ensure trimmable characters are checked at pool initialization.
603 - Fix message id integer overflow.
604 - Fix pool worker removal in worker choice strategy internals.
606 ## [2.4.0-0] - 2023-04-03
610 - Add `LESS_BUSY` worker choice strategy.
614 - Optimize worker storage in pool.
615 - Optimize worker alive status check.
616 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
617 - Optimize `LESS_USED` worker choice strategy.
621 - Ensure trimmable characters are checked at pool initialization.
622 - Fix message id integer overflow.
623 - Fix pool worker removal in worker choice strategy internals.
625 ## [2.3.10] - 2023-03-18
629 - Fix package.json `exports` syntax for ESM and CommonJS.
633 - Permit SemVer pre-release publication.
635 ## [2.3.10-2] - 2023-03-18
639 - Fix package.json `exports` syntax for ESM and CommonJS.
641 ## [2.3.10-1] - 2023-03-18
645 - Permit SemVer pre-release publication.
647 ## [2.3.10-0] - 2023-03-18
651 - Fix package.json `exports` syntax for ESM and CommonJS.
653 ## [2.3.9] - 2023-03-18
657 - Introduce ESM module support along with CommonJS one.
661 - Fix brown paper bag bug referencing the same object literal.
663 ## [2.3.8] - 2023-03-18
667 - Switch internal benchmarking code to benny.
668 - Switch to TypeScript 5.x.x.
669 - Switch rollup bundler plugins to core ones.
670 - Switch to TSDoc syntax.
671 - Enforce conventional commits.
675 - Fix random integer generator.
676 - Fix worker choice strategy pool type identification at initialization.
678 ## [2.3.7] - 2022-10-23
682 - Switch to open collective FOSS project funding platform.
683 - Switch to ts-standard linter configuration on TypeScript code.
687 - Fixed missing async on pool execute method.
688 - Fixed typing in TypeScript example.
689 - Fixed types in unit tests.
691 ## [2.3.6] - 2022-10-22
695 - Cleanup pool attributes and methods.
696 - Refine error types thrown.
700 - Fix continuous integration build on windows.
701 - Fix code coverage reporting by using c8 instead of nyc.
703 ## [2.3.5] - 2022-10-21
707 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
708 - Optimize tasks usage lookup implementation.
712 - Fix missed pool event emitter type export.
713 - Fix typedoc documentation generation.
715 ## [2.3.4] - 2022-10-17
719 - Fully automate release process with release-it.
723 - Optimize fair share task scheduling algorithm implementation.
724 - Update benchmarks versus external pools results with latest version.
726 ## [2.3.3] - 2022-10-15
730 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
732 ## [2.3.2] - 2022-10-14
736 - Optimize fair share worker selection strategy implementation.
740 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
742 ## [2.3.1] - 2022-10-13
746 - Pool worker choice strategies:
747 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
748 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
750 ## [2.2.2] - 2022-10-09
754 - Fixed `README.md` file.
756 ## [2.2.1] - 2022-10-08
760 - Dynamic worker choice strategy change at runtime.
762 ## [2.2.0] - 2022-01-05
766 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
768 ## [2.1.0] - 2021-08-29
772 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
776 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
777 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
778 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
779 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
781 ## [2.0.2] - 2021-05-12
785 - Fix `busy` event emission on fixed pool type
787 ## [2.0.1] - 2021-03-16
791 - Check if pool options are properly set.
792 - `busy` event is emitted on all pool types.
794 ## [2.0.0] - 2021-03-01
798 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
802 - `FullPool` event is now renamed to `busy`.
803 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
804 _Find more details on our JSDoc._
806 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
808 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
810 ### Pool options types declaration merge
812 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
814 #### New `export` strategy
818 const DynamicThreadPool = require('poolifier/lib/dynamic')
820 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
823 But you should always prefer just using
826 const { DynamicThreadPool } = require('poolifier')
829 #### New type definitions for input data and response
831 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
832 _This is not a limitation by poolifier but Node.js._
834 #### Public property replacements
836 `numWorkers` property is now `numberOfWorkers`
838 #### Internal (protected) properties and methods renaming
840 These properties are not intended for end users
842 - `id` => `nextMessageId`
844 These methods are not intended for end users
846 - `_chooseWorker` => `chooseWorker`
847 - `_newWorker` => `createWorker`
848 - `_execute` => `internalExecute`
849 - `_chooseWorker` => `chooseWorker`
850 - `_checkAlive` => `checkAlive`
852 - `_runAsync` => `runAsync`
854 ## [1.1.0] - 2020-05-21
858 - ThreadWorker support async functions as option
859 - Various external library patches
861 ## [1.0.0] - 2020-01-24
865 - FixedThreadPool implementation
866 - DynamicThreadPool implementation
867 - WorkerThread implementation to improve developer experience