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 - Disable publication on GitHub packages registry on release until authentication issue is fixed.
16 - Add `startWorkers` to pool options to whether start the minimum number of workers at pool creation or not.
17 - Add `start()` method to pool API to start the minimum number of workers.
18 - Add `taskStealing` and `tasksStealingOnPressure` to tasks queue options to whether enable task stealing or not and whether enable tasks stealing on back pressure or not.
19 - Continuous internal benchmarking: https://poolifier.github.io/benchmark-results/dev/bench.
21 ## [2.6.44] - 2023-09-08
25 - Use a dedicated PAT to publish on GitHub packages registry.
29 - Publish on GitHub packages registry on release.
33 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
35 ## [2.6.43] - 2023-09-08
39 - Publish on GitHub packages registry on release.
43 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
45 ## [2.6.42] - 2023-09-06
49 - Optimize hot code paths implementation: avoid unnecessary branching, add and use optimized helpers (min, max), use reduce() array helper, ...
51 ## [2.6.41] - 2023-09-03
55 - Optimize worker choice strategies implementation.
57 ## [2.6.40] - 2023-09-01
61 - Do not pre-choose in WRR worker choice strategy to avoid bias.
62 - Avoid array out of bound in worker choice strategies after worker node removal.
64 ## [2.6.39] - 2023-08-30
68 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized.
70 ## [2.6.38] - 2023-08-30
74 - Bundle typescript types declaration into one file.
78 - Improve interleaved weighted round robin worker choice strategy implementation.
80 ## [2.6.37] - 2023-08-28
84 - Ensure unused worker usage statistics are deleted at runtime.
88 - Rename worker choice strategy options `choiceRetries` to `retries`.
89 - Avoid unnecessary branching in worker choice strategies.
91 ## [2.6.36] - 2023-08-27
95 - Fix pool `execute()` arguments check.
99 - Make continuous tasks stealing algorithm less aggressive.
100 - Fine tune tasks stealing algorithm under back pressure.
102 ## [2.6.35] - 2023-08-25
106 - Don't account worker usage statistics for tasks that have failed.
107 - Fix pool information runtime and wait time median computation.
111 - Update simple moving average implementation to use a circular buffer.
112 - Update simple moving median implementation to use a circular buffer.
113 - Account for stolen tasks in worker usage statistics and pool information.
117 - Continuous tasks stealing algorithm.
119 ## [2.6.34] - 2023-08-24
123 - Avoid cascading tasks stealing under back pressure.
127 - Add fastpath to queued tasks rescheduling.
129 ## [2.6.33] - 2023-08-24
133 - Fix queued tasks rescheduling.
137 - Rename tasks queue options `queueMaxSize` to `size`.
141 - Task stealing scheduling algorithm if tasks queueing is enabled.
143 ## [2.6.32] - 2023-08-23
147 - Ensure no task can be executed when the pool is destroyed.
151 - Add `queueMaxSize` option to tasks queue options.
152 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
153 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
155 ## [2.6.31] - 2023-08-20
159 - Fix worker choice strategy retries mechanism in some edge cases.
163 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
164 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
166 ## [2.6.30] - 2023-08-19
170 - Ensure pool event `backPressure` is emitted.
171 - Ensure pool event `full` is emitted only once.
172 - Ensure worker node cannot be instantiated without proper arguments.
174 ## [2.6.29] - 2023-08-18
178 - Fix race condition between ready and task functions worker message handling at startup.
179 - Fix duplicate task function worker usage statistics computation per task function.
180 - Update task function worker usage statistics if and only if there's at least two different task functions.
181 - Fix race condition at task function worker usage executing task computation leading to negative value.
185 - 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).
186 - Use back pressure detection in worker choice strategies.
187 - Add worker choice strategies retries mechanism if no worker is eligible.
189 ## [2.6.28] - 2023-08-16
193 - Ensure pool workers are properly initialized.
197 - HTTP server pool examples: express-cluster, express-hybrid.
201 - Remove now useless branching in worker hot code path.
203 ## [2.6.27] - 2023-08-15
207 - Add `KillHandler` type definition to exported types.
211 - Add `destroy` event to pool API.
213 ## [2.6.26] - 2023-08-15
217 - Add kill handler to worker options allowing to execute custom code when worker is killed.
218 - Add `listTaskFunctions()` method to pool API.
219 - SMTP client pool example: nodemailer.
221 ## [2.6.25] - 2023-08-13
225 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
226 - WebSocket server pool examples: ws-cluster, ws-hybrid.
228 ## [2.6.24] - 2023-08-12
232 - Add array of transferable objects to the `execute()` method arguments.
233 - WebSocket server pool examples: ws-worker_threads.
235 ## [2.6.23] - 2023-08-11
239 - 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.
243 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
244 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
246 ## [2.6.22] - 2023-08-10
250 - Add missing `types` field to package.json `exports`.
254 - Structure markdown documentation (PR #811).
256 ## [2.6.21] - 2023-08-03
260 - Improve code documentation.
261 - Code refactoring and cleanup for better maintainability and readability.
263 ## [2.6.20] - 2023-07-21
267 - Fix queued tasks redistribution on error task execution starvation.
268 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
272 - Drastically reduce lookups by worker in the worker nodes.
274 ## [2.6.19] - 2023-07-20
278 - Dedicated internal communication channel for worker_threads pools.
280 ## [2.6.18] - 2023-07-19
284 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
286 ## [2.6.17] - 2023-07-16
290 - Add `listTaskFunctions()` method to worker API.
292 ## [2.6.16] - 2023-07-12
296 - Fix pool startup detection.
297 - Fix worker task functions handling.
299 ## [2.6.15] - 2023-07-11
303 - Take into account worker node readiness in worker choice strategies.
305 ## [2.6.14] - 2023-07-10
309 - Fix task function statistics tracking.
311 ## [2.6.13] - 2023-07-10
315 - Add per task function statistics tracking.
316 - Add public methods to manipulate the worker task functions at runtime.
318 ## [2.6.12] - 2023-07-09
322 - Workaround import issue with `node:os` module in node 16.x.x.
324 ## [2.6.11] - 2023-07-09
328 - Fix pool readiness semantic.
330 ## [2.6.10] - 2023-07-08
334 - Ensure workers are not recreated on error at pool startup.
338 - Add `ready` and `strategy` fields to pool information.
339 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
340 - Add dynamic pool sizing checks.
342 ## [2.6.9] - 2023-07-07
346 - Recreate the right worker type on uncaught exception.
350 - Add minimum and maximum to internal measurement statistics.
351 - Add `runTime` and `waitTime` to pool information.
352 - Check worker inactive time only on dynamic worker.
354 ## [2.6.8] - 2023-07-03
358 - Brown paper bag release to fix version handling in pool information.
360 ## [2.6.7] - 2023-07-03
364 - Ensure worker queued tasks at error are reassigned to other pool workers.
368 - Add pool `utilization` ratio to pool information.
369 - Add `version` to pool information.
370 - Add worker information to worker nodes.
372 ## [2.6.6] - 2023-07-01
376 - Add safe helper `availableParallelism()` to help sizing the pool.
380 - Ensure message handler is only registered in worker.
382 ## [2.6.5] - 2023-06-27
386 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
390 - Artificial version bump to 2.6.5 to workaround publication issue.
391 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
392 - Ensure pool event is emitted before task error promise rejection.
393 - Fix queued tasks count computation.
397 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
399 ## [2.6.4] - 2023-06-27
403 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
407 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
408 - Ensure pool event is emitted before task error promise rejection.
409 - Fix queued tasks count computation.
413 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
415 ## [2.6.3] - 2023-06-19
419 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
420 - Update strategies internals after statistics computation.
424 - Optimize O(1) queue implementation.
426 ## [2.6.2] - 2023-06-12
430 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
432 ## [2.6.1] - 2023-06-10
436 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
440 - Fix average statistics computation: ensure failed tasks are not accounted.
442 ## [2.6.0] - 2023-06-09
446 - Add `LEAST_ELU` worker choice strategy (experimental).
447 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
451 - Refactor pool worker node usage internals.
452 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
453 - Breaking change: pool information `info` property object fields have been renamed.
457 - Fix wait time accounting.
458 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
459 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
461 ## [2.5.4] - 2023-06-07
465 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
469 - Compute statistics at the worker level only if needed.
470 - Add `worker_threads` options to thread pool options.
474 - Make the `LEAST_BUSY` strategy only relies on task runtime.
476 ## [2.5.3] - 2023-06-04
480 - Refine pool information content.
481 - Limit pool internals public exposure.
483 ## [2.5.2] - 2023-06-02
487 - Add `taskError` pool event for task execution error.
488 - Add pool information `info` property to pool.
489 - Emit pool information on `busy` and `full` pool events.
491 ## [2.5.1] - 2023-06-01
495 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
496 - Add `error` pool event for uncaught worker error.
498 ## [2.5.0] - 2023-05-31
502 - Switch pool event emitter to `EventEmitterAsyncResource`.
503 - Add tasks wait time accounting in per worker tasks usage.
504 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
508 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
510 ## [2.4.14] - 2023-05-09
514 - Ensure no undefined task runtime can land in the tasks history.
515 - Fix median computation implementation once again.
519 - Unit tests for median and queue implementations.
521 ## [2.4.13] - 2023-05-08
525 - Fix worker choice strategy options validation.
526 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
528 ## [2.4.12] - 2023-05-06
532 - Support multiple task functions per worker.
533 - Add custom worker weights support to worker choice strategies options.
537 - Use O(1) queue implementation for tasks queueing.
541 - Fix median computation implementation.
542 - Fix fair share worker choice strategy internals update.
544 ## [2.4.11] - 2023-04-23
548 - Optimize free worker finding in worker choice strategies.
550 ## [2.4.10] - 2023-04-15
554 - Fix typescript type definition for task function: ensure the input data is optional.
555 - Fix typescript type definition for pool execute(): ensure the input data is optional.
557 ## [2.4.9] - 2023-04-15
561 - Add tasks queue enablement runtime setter to pool.
562 - Add tasks queue options runtime setter to pool.
563 - Add worker choice strategy options runtime setter to pool.
567 - Remove the tasks queuing experimental status.
571 - Fix task function type definition and validation.
572 - Fix worker choice strategy options handling.
574 ## [2.4.8] - 2023-04-12
578 - Fix message between main worker and worker type definition for tasks.
579 - Fix code documentation.
581 ## [2.4.7] - 2023-04-11
585 - Add worker tasks queue options to pool options.
589 - Fix missing documentation.
591 ## [2.4.6] - 2023-04-10
595 - Ensure one task at a time is executed per worker with tasks queueing enabled.
596 - Properly count worker executing tasks with tasks queueing enabled.
598 ## [2.4.5] - 2023-04-09
602 - Use monotonic high resolution timer for worker tasks runtime.
603 - Add worker tasks median runtime to statistics.
604 - Add worker tasks queue (experimental).
606 ## [2.4.4] - 2023-04-07
610 - Add `PoolEvents` enumeration and `PoolEvent` type.
614 - Destroy worker only on alive check.
616 ## [2.4.3] - 2023-04-07
620 - Fix typedoc generation with inheritance.
622 ## [2.4.2] - 2023-04-06
626 - Add `full` event to dynamic pool.
627 - Keep worker choice strategy in memory for conditional reuse.
631 - Fix possible negative worker key at worker removal in worker choice strategies.
633 ## [2.4.1] - 2023-04-05
637 - Optimize worker choice strategy for dynamic pool.
641 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
643 ## [2.4.0] - 2023-04-04
647 - Add `LESS_BUSY` worker choice strategy.
651 - Optimize worker storage in pool.
652 - Optimize worker alive status check.
653 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
654 - Optimize `LESS_USED` worker choice strategy.
655 - Update benchmark versus external threads pools.
656 - Optimize tasks usage statistics requirements for worker choice strategy.
660 - Ensure trimmable characters are checked at pool initialization.
661 - Fix message id integer overflow.
662 - Fix pool worker removal in worker choice strategy internals.
663 - Fix package publication with pnpm.
665 ## [2.4.0-3] - 2023-04-04
669 - Add `LESS_BUSY` worker choice strategy.
673 - Optimize worker storage in pool.
674 - Optimize worker alive status check.
675 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
676 - Optimize `LESS_USED` worker choice strategy.
677 - Update benchmark versus external threads pools.
681 - Ensure trimmable characters are checked at pool initialization.
682 - Fix message id integer overflow.
683 - Fix pool worker removal in worker choice strategy internals.
684 - Fix package publication with pnpm.
686 ## [2.4.0-2] - 2023-04-03
690 - Add `LESS_BUSY` worker choice strategy.
694 - Optimize worker storage in pool.
695 - Optimize worker alive status check.
696 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
697 - Optimize `LESS_USED` worker choice strategy.
701 - Ensure trimmable characters are checked at pool initialization.
702 - Fix message id integer overflow.
703 - Fix pool worker removal in worker choice strategy internals.
704 - Fix package publication with pnpm.
706 ## [2.4.0-1] - 2023-04-03
710 - Add `LESS_BUSY` worker choice strategy.
714 - Optimize worker storage in pool.
715 - Optimize worker alive status check.
716 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
717 - Optimize `LESS_USED` worker choice strategy.
721 - Ensure trimmable characters are checked at pool initialization.
722 - Fix message id integer overflow.
723 - Fix pool worker removal in worker choice strategy internals.
725 ## [2.4.0-0] - 2023-04-03
729 - Add `LESS_BUSY` worker choice strategy.
733 - Optimize worker storage in pool.
734 - Optimize worker alive status check.
735 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
736 - Optimize `LESS_USED` worker choice strategy.
740 - Ensure trimmable characters are checked at pool initialization.
741 - Fix message id integer overflow.
742 - Fix pool worker removal in worker choice strategy internals.
744 ## [2.3.10] - 2023-03-18
748 - Fix package.json `exports` syntax for ESM and CommonJS.
752 - Permit SemVer pre-release publication.
754 ## [2.3.10-2] - 2023-03-18
758 - Fix package.json `exports` syntax for ESM and CommonJS.
760 ## [2.3.10-1] - 2023-03-18
764 - Permit SemVer pre-release publication.
766 ## [2.3.10-0] - 2023-03-18
770 - Fix package.json `exports` syntax for ESM and CommonJS.
772 ## [2.3.9] - 2023-03-18
776 - Introduce ESM module support along with CommonJS one.
780 - Fix brown paper bag bug referencing the same object literal.
782 ## [2.3.8] - 2023-03-18
786 - Switch internal benchmarking code to benny.
787 - Switch to TypeScript 5.x.x.
788 - Switch rollup bundler plugins to core ones.
789 - Switch to TSDoc syntax.
790 - Enforce conventional commits.
794 - Fix random integer generator.
795 - Fix worker choice strategy pool type identification at initialization.
797 ## [2.3.7] - 2022-10-23
801 - Switch to open collective FOSS project funding platform.
802 - Switch to ts-standard linter configuration on TypeScript code.
806 - Fixed missing async on pool execute method.
807 - Fixed typing in TypeScript example.
808 - Fixed types in unit tests.
810 ## [2.3.6] - 2022-10-22
814 - Cleanup pool attributes and methods.
815 - Refine error types thrown.
819 - Fix continuous integration build on windows.
820 - Fix code coverage reporting by using c8 instead of nyc.
822 ## [2.3.5] - 2022-10-21
826 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
827 - Optimize tasks usage lookup implementation.
831 - Fix missed pool event emitter type export.
832 - Fix typedoc documentation generation.
834 ## [2.3.4] - 2022-10-17
838 - Fully automate release process with release-it.
842 - Optimize fair share task scheduling algorithm implementation.
843 - Update benchmark versus external pools results with latest version.
845 ## [2.3.3] - 2022-10-15
849 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
851 ## [2.3.2] - 2022-10-14
855 - Optimize fair share worker selection strategy implementation.
859 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
861 ## [2.3.1] - 2022-10-13
865 - Pool worker choice strategies:
866 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
867 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
869 ## [2.2.2] - 2022-10-09
873 - Fixed `README.md` file.
875 ## [2.2.1] - 2022-10-08
879 - Dynamic worker choice strategy change at runtime.
881 ## [2.2.0] - 2022-01-05
885 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
887 ## [2.1.0] - 2021-08-29
891 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
895 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
896 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
897 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
898 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
900 ## [2.0.2] - 2021-05-12
904 - Fix `busy` event emission on fixed pool type
906 ## [2.0.1] - 2021-03-16
910 - Check if pool options are properly set.
911 - `busy` event is emitted on all pool types.
913 ## [2.0.0] - 2021-03-01
917 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
921 - `FullPool` event is now renamed to `busy`.
922 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
923 _Find more details on our JSDoc._
925 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
927 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
929 ### Pool options types declaration merge
931 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
933 #### New `export` strategy
937 const DynamicThreadPool = require('poolifier/lib/dynamic')
939 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
942 But you should always prefer just using
945 const { DynamicThreadPool } = require('poolifier')
948 #### New type definitions for input data and response
950 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
951 _This is not a limitation by poolifier but Node.js._
953 #### Public property replacements
955 `numWorkers` property is now `numberOfWorkers`
957 #### Internal (protected) properties and methods renaming
959 These properties are not intended for end users
961 - `id` => `nextMessageId`
963 These methods are not intended for end users
965 - `_chooseWorker` => `chooseWorker`
966 - `_newWorker` => `createWorker`
967 - `_execute` => `internalExecute`
968 - `_chooseWorker` => `chooseWorker`
969 - `_checkAlive` => `checkAlive`
971 - `_runAsync` => `runAsync`
973 ## [1.1.0] - 2020-05-21
977 - ThreadWorker support async functions as option
978 - Various external library patches
980 ## [1.0.0] - 2020-01-24
984 - FixedThreadPool implementation
985 - DynamicThreadPool implementation
986 - WorkerThread implementation to improve developer experience