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 ## [2.7.3] - 2023-09-24
14 - Convert pool event emitter to event emitter async resource.
16 ## [2.7.2] - 2023-09-23
20 - Add source maps to npm package to ease debugging.
24 - Continuous benchmarking versus other worker pools: [https://poolifier.github.io/benchmark](https://poolifier.github.io/benchmark).
26 ## [2.7.1] - 2023-09-20
30 - Ensure worker message listener used one time are removed after usage.
32 ## [2.7.0] - 2023-09-19
36 - Fix task stealing related tasks queue options handling at runtime.
40 - Rename `listTaskFunctions()` to `listTaskFunctionNames()` in pool and worker API.
44 - Add `hasTaskFunction()`, `addTaskFunction()`, `removeTaskFunction()`, `setDefaultTaskFunction()` methods to pool API: [PR #1148](https://github.com/poolifier/poolifier/pull/1148).
45 - Stricter worker constructor arguments validation.
47 ## [2.6.45] - 2023-09-17
51 - Disable publication on GitHub packages registry on release until authentication issue is fixed.
55 - Add `startWorkers` to pool options to whether start the minimum number of workers at pool initialization or not.
56 - Add `start()` method to pool API to start the minimum number of workers.
57 - 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.
58 - Continuous internal benchmarking: [https://poolifier.github.io/benchmark-results/dev/bench](https://poolifier.github.io/benchmark-results/dev/bench).
60 ## [2.6.44] - 2023-09-08
64 - Use a dedicated PAT to publish on GitHub packages registry.
68 - Publish on GitHub packages registry on release.
72 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
74 ## [2.6.43] - 2023-09-08
78 - Publish on GitHub packages registry on release.
82 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
84 ## [2.6.42] - 2023-09-06
88 - Optimize hot code paths implementation: avoid unnecessary branching, add and use optimized helpers (min, max), use reduce() array helper, ...
90 ## [2.6.41] - 2023-09-03
94 - Optimize worker choice strategies implementation.
96 ## [2.6.40] - 2023-09-01
100 - Do not pre-choose in WRR worker choice strategy to avoid bias.
101 - Avoid array out of bound in worker choice strategies after worker node removal.
103 ## [2.6.39] - 2023-08-30
107 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized.
109 ## [2.6.38] - 2023-08-30
113 - Bundle typescript types declaration into one file.
117 - Improve interleaved weighted round robin worker choice strategy implementation.
119 ## [2.6.37] - 2023-08-28
123 - Ensure unused worker usage statistics are deleted at runtime.
127 - Rename worker choice strategy options `choiceRetries` to `retries`.
128 - Avoid unnecessary branching in worker choice strategies.
130 ## [2.6.36] - 2023-08-27
134 - Fix pool `execute()` arguments check.
138 - Make continuous tasks stealing algorithm less aggressive.
139 - Fine tune tasks stealing algorithm under back pressure.
141 ## [2.6.35] - 2023-08-25
145 - Don't account worker usage statistics for tasks that have failed.
146 - Fix pool information runtime and wait time median computation.
150 - Update simple moving average implementation to use a circular buffer.
151 - Update simple moving median implementation to use a circular buffer.
152 - Account for stolen tasks in worker usage statistics and pool information.
156 - Continuous tasks stealing algorithm.
158 ## [2.6.34] - 2023-08-24
162 - Avoid cascading tasks stealing under back pressure.
166 - Add fastpath to queued tasks rescheduling.
168 ## [2.6.33] - 2023-08-24
172 - Fix queued tasks rescheduling.
176 - Rename tasks queue options `queueMaxSize` to `size`.
180 - Task stealing scheduling algorithm if tasks queueing is enabled.
182 ## [2.6.32] - 2023-08-23
186 - Ensure no task can be executed when the pool is destroyed.
190 - Add `queueMaxSize` option to tasks queue options.
191 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
192 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
194 ## [2.6.31] - 2023-08-20
198 - Fix worker choice strategy retries mechanism in some edge cases.
202 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
203 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
205 ## [2.6.30] - 2023-08-19
209 - Ensure pool event `backPressure` is emitted.
210 - Ensure pool event `full` is emitted only once.
211 - Ensure worker node cannot be instantiated without proper arguments.
213 ## [2.6.29] - 2023-08-18
217 - Fix race condition between ready and task functions worker message handling at startup.
218 - Fix duplicate task function worker usage statistics computation per task function.
219 - Update task function worker usage statistics if and only if there's at least two different task functions.
220 - Fix race condition at task function worker usage executing task computation leading to negative value.
224 - 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).
225 - Use back pressure detection in worker choice strategies.
226 - Add worker choice strategies retries mechanism if no worker is eligible.
228 ## [2.6.28] - 2023-08-16
232 - Ensure pool workers are properly initialized.
236 - HTTP server pool examples: express-cluster, express-hybrid.
240 - Remove now useless branching in worker hot code path.
242 ## [2.6.27] - 2023-08-15
246 - Add `KillHandler` type definition to exported types.
250 - Add `destroy` event to pool API.
252 ## [2.6.26] - 2023-08-15
256 - Add kill handler to worker options allowing to execute custom code when worker is killed.
257 - Add `listTaskFunctions()` method to pool API.
258 - SMTP client pool example: nodemailer.
260 ## [2.6.25] - 2023-08-13
264 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
265 - WebSocket server pool examples: ws-cluster, ws-hybrid.
267 ## [2.6.24] - 2023-08-12
271 - Add array of transferable objects to the `execute()` method arguments.
272 - WebSocket server pool examples: ws-worker_threads.
274 ## [2.6.23] - 2023-08-11
278 - 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.
282 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
283 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
285 ## [2.6.22] - 2023-08-10
289 - Add missing `types` field to package.json `exports`.
293 - Structure markdown documentation (PR #811).
295 ## [2.6.21] - 2023-08-03
299 - Improve code documentation.
300 - Code refactoring and cleanup for better maintainability and readability.
302 ## [2.6.20] - 2023-07-21
306 - Fix queued tasks redistribution on error task execution starvation.
307 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
311 - Drastically reduce lookups by worker in the worker nodes.
313 ## [2.6.19] - 2023-07-20
317 - Dedicated internal communication channel for worker_threads pools.
319 ## [2.6.18] - 2023-07-19
323 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
325 ## [2.6.17] - 2023-07-16
329 - Add `listTaskFunctions()` method to worker API.
331 ## [2.6.16] - 2023-07-12
335 - Fix pool startup detection.
336 - Fix worker task functions handling.
338 ## [2.6.15] - 2023-07-11
342 - Take into account worker node readiness in worker choice strategies.
344 ## [2.6.14] - 2023-07-10
348 - Fix task function statistics tracking.
350 ## [2.6.13] - 2023-07-10
354 - Add per task function statistics tracking.
355 - Add public methods to manipulate the worker task functions at runtime.
357 ## [2.6.12] - 2023-07-09
361 - Workaround import issue with `node:os` module in node 16.x.x.
363 ## [2.6.11] - 2023-07-09
367 - Fix pool readiness semantic.
369 ## [2.6.10] - 2023-07-08
373 - Ensure workers are not recreated on error at pool startup.
377 - Add `ready` and `strategy` fields to pool information.
378 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
379 - Add dynamic pool sizing checks.
381 ## [2.6.9] - 2023-07-07
385 - Recreate the right worker type on uncaught exception.
389 - Add minimum and maximum to internal measurement statistics.
390 - Add `runTime` and `waitTime` to pool information.
391 - Check worker inactive time only on dynamic worker.
393 ## [2.6.8] - 2023-07-03
397 - Brown paper bag release to fix version handling in pool information.
399 ## [2.6.7] - 2023-07-03
403 - Ensure worker queued tasks at error are reassigned to other pool workers.
407 - Add pool `utilization` ratio to pool information.
408 - Add `version` to pool information.
409 - Add worker information to worker nodes.
411 ## [2.6.6] - 2023-07-01
415 - Add safe helper `availableParallelism()` to help sizing the pool.
419 - Ensure message handler is only registered in worker.
421 ## [2.6.5] - 2023-06-27
425 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
429 - Artificial version bump to 2.6.5 to workaround publication issue.
430 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
431 - Ensure pool event is emitted before task error promise rejection.
432 - Fix queued tasks count computation.
436 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
438 ## [2.6.4] - 2023-06-27
442 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
446 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
447 - Ensure pool event is emitted before task error promise rejection.
448 - Fix queued tasks count computation.
452 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
454 ## [2.6.3] - 2023-06-19
458 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
459 - Update strategies internals after statistics computation.
463 - Optimize O(1) queue implementation.
465 ## [2.6.2] - 2023-06-12
469 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
471 ## [2.6.1] - 2023-06-10
475 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
479 - Fix average statistics computation: ensure failed tasks are not accounted.
481 ## [2.6.0] - 2023-06-09
485 - Add `LEAST_ELU` worker choice strategy (experimental).
486 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
490 - Refactor pool worker node usage internals.
491 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
492 - Breaking change: pool information `info` property object fields have been renamed.
496 - Fix wait time accounting.
497 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
498 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
500 ## [2.5.4] - 2023-06-07
504 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
508 - Compute statistics at the worker level only if needed.
509 - Add `worker_threads` options to thread pool options.
513 - Make the `LEAST_BUSY` strategy only relies on task runtime.
515 ## [2.5.3] - 2023-06-04
519 - Refine pool information content.
520 - Limit pool internals public exposure.
522 ## [2.5.2] - 2023-06-02
526 - Add `taskError` pool event for task execution error.
527 - Add pool information `info` property to pool.
528 - Emit pool information on `busy` and `full` pool events.
530 ## [2.5.1] - 2023-06-01
534 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
535 - Add `error` pool event for uncaught worker error.
537 ## [2.5.0] - 2023-05-31
541 - Switch pool event emitter to `EventEmitterAsyncResource`.
542 - Add tasks wait time accounting in per worker tasks usage.
543 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
547 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
549 ## [2.4.14] - 2023-05-09
553 - Ensure no undefined task runtime can land in the tasks history.
554 - Fix median computation implementation once again.
558 - Unit tests for median and queue implementations.
560 ## [2.4.13] - 2023-05-08
564 - Fix worker choice strategy options validation.
565 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
567 ## [2.4.12] - 2023-05-06
571 - Support multiple task functions per worker.
572 - Add custom worker weights support to worker choice strategies options.
576 - Use O(1) queue implementation for tasks queueing.
580 - Fix median computation implementation.
581 - Fix fair share worker choice strategy internals update.
583 ## [2.4.11] - 2023-04-23
587 - Optimize free worker finding in worker choice strategies.
589 ## [2.4.10] - 2023-04-15
593 - Fix typescript type definition for task function: ensure the input data is optional.
594 - Fix typescript type definition for pool execute(): ensure the input data is optional.
596 ## [2.4.9] - 2023-04-15
600 - Add tasks queue enablement runtime setter to pool.
601 - Add tasks queue options runtime setter to pool.
602 - Add worker choice strategy options runtime setter to pool.
606 - Remove the tasks queuing experimental status.
610 - Fix task function type definition and validation.
611 - Fix worker choice strategy options handling.
613 ## [2.4.8] - 2023-04-12
617 - Fix message between main worker and worker type definition for tasks.
618 - Fix code documentation.
620 ## [2.4.7] - 2023-04-11
624 - Add worker tasks queue options to pool options.
628 - Fix missing documentation.
630 ## [2.4.6] - 2023-04-10
634 - Ensure one task at a time is executed per worker with tasks queueing enabled.
635 - Properly count worker executing tasks with tasks queueing enabled.
637 ## [2.4.5] - 2023-04-09
641 - Use monotonic high resolution timer for worker tasks runtime.
642 - Add worker tasks median runtime to statistics.
643 - Add worker tasks queue (experimental).
645 ## [2.4.4] - 2023-04-07
649 - Add `PoolEvents` enumeration and `PoolEvent` type.
653 - Destroy worker only on alive check.
655 ## [2.4.3] - 2023-04-07
659 - Fix typedoc generation with inheritance.
661 ## [2.4.2] - 2023-04-06
665 - Add `full` event to dynamic pool.
666 - Keep worker choice strategy in memory for conditional reuse.
670 - Fix possible negative worker key at worker removal in worker choice strategies.
672 ## [2.4.1] - 2023-04-05
676 - Optimize worker choice strategy for dynamic pool.
680 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
682 ## [2.4.0] - 2023-04-04
686 - Add `LESS_BUSY` worker choice strategy.
690 - Optimize worker storage in pool.
691 - Optimize worker alive status check.
692 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
693 - Optimize `LESS_USED` worker choice strategy.
694 - Update benchmark versus external threads pools.
695 - Optimize tasks usage statistics requirements for worker choice strategy.
699 - Ensure trimmable characters are checked at pool initialization.
700 - Fix message id integer overflow.
701 - Fix pool worker removal in worker choice strategy internals.
702 - Fix package publication with pnpm.
704 ## [2.4.0-3] - 2023-04-04
708 - Add `LESS_BUSY` worker choice strategy.
712 - Optimize worker storage in pool.
713 - Optimize worker alive status check.
714 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
715 - Optimize `LESS_USED` worker choice strategy.
716 - Update benchmark versus external threads pools.
720 - Ensure trimmable characters are checked at pool initialization.
721 - Fix message id integer overflow.
722 - Fix pool worker removal in worker choice strategy internals.
723 - Fix package publication with pnpm.
725 ## [2.4.0-2] - 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.
743 - Fix package publication with pnpm.
745 ## [2.4.0-1] - 2023-04-03
749 - Add `LESS_BUSY` worker choice strategy.
753 - Optimize worker storage in pool.
754 - Optimize worker alive status check.
755 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
756 - Optimize `LESS_USED` worker choice strategy.
760 - Ensure trimmable characters are checked at pool initialization.
761 - Fix message id integer overflow.
762 - Fix pool worker removal in worker choice strategy internals.
764 ## [2.4.0-0] - 2023-04-03
768 - Add `LESS_BUSY` worker choice strategy.
772 - Optimize worker storage in pool.
773 - Optimize worker alive status check.
774 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
775 - Optimize `LESS_USED` worker choice strategy.
779 - Ensure trimmable characters are checked at pool initialization.
780 - Fix message id integer overflow.
781 - Fix pool worker removal in worker choice strategy internals.
783 ## [2.3.10] - 2023-03-18
787 - Fix package.json `exports` syntax for ESM and CommonJS.
791 - Permit SemVer pre-release publication.
793 ## [2.3.10-2] - 2023-03-18
797 - Fix package.json `exports` syntax for ESM and CommonJS.
799 ## [2.3.10-1] - 2023-03-18
803 - Permit SemVer pre-release publication.
805 ## [2.3.10-0] - 2023-03-18
809 - Fix package.json `exports` syntax for ESM and CommonJS.
811 ## [2.3.9] - 2023-03-18
815 - Introduce ESM module support along with CommonJS one.
819 - Fix brown paper bag bug referencing the same object literal.
821 ## [2.3.8] - 2023-03-18
825 - Switch internal benchmarking code to benny.
826 - Switch to TypeScript 5.x.x.
827 - Switch rollup bundler plugins to core ones.
828 - Switch to TSDoc syntax.
829 - Enforce conventional commits.
833 - Fix random integer generator.
834 - Fix worker choice strategy pool type identification at initialization.
836 ## [2.3.7] - 2022-10-23
840 - Switch to open collective FOSS project funding platform.
841 - Switch to ts-standard linter configuration on TypeScript code.
845 - Fixed missing async on pool execute method.
846 - Fixed typing in TypeScript example.
847 - Fixed types in unit tests.
849 ## [2.3.6] - 2022-10-22
853 - Cleanup pool attributes and methods.
854 - Refine error types thrown.
858 - Fix continuous integration build on windows.
859 - Fix code coverage reporting by using c8 instead of nyc.
861 ## [2.3.5] - 2022-10-21
865 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
866 - Optimize tasks usage lookup implementation.
870 - Fix missed pool event emitter type export.
871 - Fix typedoc documentation generation.
873 ## [2.3.4] - 2022-10-17
877 - Fully automate release process with release-it.
881 - Optimize fair share task scheduling algorithm implementation.
882 - Update benchmark versus external pools results with latest version.
884 ## [2.3.3] - 2022-10-15
888 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
890 ## [2.3.2] - 2022-10-14
894 - Optimize fair share worker selection strategy implementation.
898 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
900 ## [2.3.1] - 2022-10-13
904 - Pool worker choice strategies:
905 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
906 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
908 ## [2.2.2] - 2022-10-09
912 - Fixed `README.md` file.
914 ## [2.2.1] - 2022-10-08
918 - Dynamic worker choice strategy change at runtime.
920 ## [2.2.0] - 2022-01-05
924 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
926 ## [2.1.0] - 2021-08-29
930 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
934 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
935 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
936 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
937 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
939 ## [2.0.2] - 2021-05-12
943 - Fix `busy` event emission on fixed pool type
945 ## [2.0.1] - 2021-03-16
949 - Check if pool options are properly set.
950 - `busy` event is emitted on all pool types.
952 ## [2.0.0] - 2021-03-01
956 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
960 - `FullPool` event is now renamed to `busy`.
961 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
962 _Find more details on our JSDoc._
964 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
966 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
968 ### Pool options types declaration merge
970 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
972 #### New `export` strategy
976 const DynamicThreadPool = require('poolifier/lib/dynamic')
978 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
981 But you should always prefer just using
984 const { DynamicThreadPool } = require('poolifier')
987 #### New type definitions for input data and response
989 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
990 _This is not a limitation by poolifier but Node.js._
992 #### Public property replacements
994 `numWorkers` property is now `numberOfWorkers`
996 #### Internal (protected) properties and methods renaming
998 These properties are not intended for end users
1000 - `id` => `nextMessageId`
1002 These methods are not intended for end users
1004 - `_chooseWorker` => `chooseWorker`
1005 - `_newWorker` => `createWorker`
1006 - `_execute` => `internalExecute`
1007 - `_chooseWorker` => `chooseWorker`
1008 - `_checkAlive` => `checkAlive`
1010 - `_runAsync` => `runAsync`
1012 ## [1.1.0] - 2020-05-21
1016 - ThreadWorker support async functions as option
1017 - Various external library patches
1019 ## [1.0.0] - 2020-01-24
1023 - FixedThreadPool implementation
1024 - DynamicThreadPool implementation
1025 - WorkerThread implementation to improve developer experience