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 ## [2.7.4] - 2023-09-25
14 - Fix source maps (bundler issue).
16 ## [2.7.3] - 2023-09-24
20 - Convert pool event emitter to event emitter async resource.
22 ## [2.7.2] - 2023-09-23
26 - Add source maps to npm package to ease debugging.
30 - Continuous benchmarking versus other worker pools: [https://poolifier.github.io/benchmark](https://poolifier.github.io/benchmark).
32 ## [2.7.1] - 2023-09-20
36 - Ensure worker message listener used one time are removed after usage.
38 ## [2.7.0] - 2023-09-19
42 - Fix task stealing related tasks queue options handling at runtime.
46 - Rename `listTaskFunctions()` to `listTaskFunctionNames()` in pool and worker API.
50 - Add `hasTaskFunction()`, `addTaskFunction()`, `removeTaskFunction()`, `setDefaultTaskFunction()` methods to pool API: [PR #1148](https://github.com/poolifier/poolifier/pull/1148).
51 - Stricter worker constructor arguments validation.
53 ## [2.6.45] - 2023-09-17
57 - Disable publication on GitHub packages registry on release until authentication issue is fixed.
61 - Add `startWorkers` to pool options to whether start the minimum number of workers at pool initialization or not.
62 - Add `start()` method to pool API to start the minimum number of workers.
63 - 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.
64 - Continuous internal benchmarking: [https://poolifier.github.io/benchmark-results/dev/bench](https://poolifier.github.io/benchmark-results/dev/bench).
66 ## [2.6.44] - 2023-09-08
70 - Use a dedicated PAT to publish on GitHub packages registry.
74 - Publish on GitHub packages registry on release.
78 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
80 ## [2.6.43] - 2023-09-08
84 - Publish on GitHub packages registry on release.
88 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
90 ## [2.6.42] - 2023-09-06
94 - Optimize hot code paths implementation: avoid unnecessary branching, add and use optimized helpers (min, max), use reduce() array helper, ...
96 ## [2.6.41] - 2023-09-03
100 - Optimize worker choice strategies implementation.
102 ## [2.6.40] - 2023-09-01
106 - Do not pre-choose in WRR worker choice strategy to avoid bias.
107 - Avoid array out of bound in worker choice strategies after worker node removal.
109 ## [2.6.39] - 2023-08-30
113 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized.
115 ## [2.6.38] - 2023-08-30
119 - Bundle typescript types declaration into one file.
123 - Improve interleaved weighted round robin worker choice strategy implementation.
125 ## [2.6.37] - 2023-08-28
129 - Ensure unused worker usage statistics are deleted at runtime.
133 - Rename worker choice strategy options `choiceRetries` to `retries`.
134 - Avoid unnecessary branching in worker choice strategies.
136 ## [2.6.36] - 2023-08-27
140 - Fix pool `execute()` arguments check.
144 - Make continuous tasks stealing algorithm less aggressive.
145 - Fine tune tasks stealing algorithm under back pressure.
147 ## [2.6.35] - 2023-08-25
151 - Don't account worker usage statistics for tasks that have failed.
152 - Fix pool information runtime and wait time median computation.
156 - Update simple moving average implementation to use a circular buffer.
157 - Update simple moving median implementation to use a circular buffer.
158 - Account for stolen tasks in worker usage statistics and pool information.
162 - Continuous tasks stealing algorithm.
164 ## [2.6.34] - 2023-08-24
168 - Avoid cascading tasks stealing under back pressure.
172 - Add fastpath to queued tasks rescheduling.
174 ## [2.6.33] - 2023-08-24
178 - Fix queued tasks rescheduling.
182 - Rename tasks queue options `queueMaxSize` to `size`.
186 - Task stealing scheduling algorithm if tasks queueing is enabled.
188 ## [2.6.32] - 2023-08-23
192 - Ensure no task can be executed when the pool is destroyed.
196 - Add `queueMaxSize` option to tasks queue options.
197 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
198 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
200 ## [2.6.31] - 2023-08-20
204 - Fix worker choice strategy retries mechanism in some edge cases.
208 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
209 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
211 ## [2.6.30] - 2023-08-19
215 - Ensure pool event `backPressure` is emitted.
216 - Ensure pool event `full` is emitted only once.
217 - Ensure worker node cannot be instantiated without proper arguments.
219 ## [2.6.29] - 2023-08-18
223 - Fix race condition between ready and task functions worker message handling at startup.
224 - Fix duplicate task function worker usage statistics computation per task function.
225 - Update task function worker usage statistics if and only if there's at least two different task functions.
226 - Fix race condition at task function worker usage executing task computation leading to negative value.
230 - 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).
231 - Use back pressure detection in worker choice strategies.
232 - Add worker choice strategies retries mechanism if no worker is eligible.
234 ## [2.6.28] - 2023-08-16
238 - Ensure pool workers are properly initialized.
242 - HTTP server pool examples: express-cluster, express-hybrid.
246 - Remove now useless branching in worker hot code path.
248 ## [2.6.27] - 2023-08-15
252 - Add `KillHandler` type definition to exported types.
256 - Add `destroy` event to pool API.
258 ## [2.6.26] - 2023-08-15
262 - Add kill handler to worker options allowing to execute custom code when worker is killed.
263 - Add `listTaskFunctions()` method to pool API.
264 - SMTP client pool example: nodemailer.
266 ## [2.6.25] - 2023-08-13
270 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
271 - WebSocket server pool examples: ws-cluster, ws-hybrid.
273 ## [2.6.24] - 2023-08-12
277 - Add array of transferable objects to the `execute()` method arguments.
278 - WebSocket server pool examples: ws-worker_threads.
280 ## [2.6.23] - 2023-08-11
284 - 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.
288 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
289 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
291 ## [2.6.22] - 2023-08-10
295 - Add missing `types` field to package.json `exports`.
299 - Structure markdown documentation (PR #811).
301 ## [2.6.21] - 2023-08-03
305 - Improve code documentation.
306 - Code refactoring and cleanup for better maintainability and readability.
308 ## [2.6.20] - 2023-07-21
312 - Fix queued tasks redistribution on error task execution starvation.
313 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
317 - Drastically reduce lookups by worker in the worker nodes.
319 ## [2.6.19] - 2023-07-20
323 - Dedicated internal communication channel for worker_threads pools.
325 ## [2.6.18] - 2023-07-19
329 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
331 ## [2.6.17] - 2023-07-16
335 - Add `listTaskFunctions()` method to worker API.
337 ## [2.6.16] - 2023-07-12
341 - Fix pool startup detection.
342 - Fix worker task functions handling.
344 ## [2.6.15] - 2023-07-11
348 - Take into account worker node readiness in worker choice strategies.
350 ## [2.6.14] - 2023-07-10
354 - Fix task function statistics tracking.
356 ## [2.6.13] - 2023-07-10
360 - Add per task function statistics tracking.
361 - Add public methods to manipulate the worker task functions at runtime.
363 ## [2.6.12] - 2023-07-09
367 - Workaround import issue with `node:os` module in node 16.x.x.
369 ## [2.6.11] - 2023-07-09
373 - Fix pool readiness semantic.
375 ## [2.6.10] - 2023-07-08
379 - Ensure workers are not recreated on error at pool startup.
383 - Add `ready` and `strategy` fields to pool information.
384 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
385 - Add dynamic pool sizing checks.
387 ## [2.6.9] - 2023-07-07
391 - Recreate the right worker type on uncaught exception.
395 - Add minimum and maximum to internal measurement statistics.
396 - Add `runTime` and `waitTime` to pool information.
397 - Check worker inactive time only on dynamic worker.
399 ## [2.6.8] - 2023-07-03
403 - Brown paper bag release to fix version handling in pool information.
405 ## [2.6.7] - 2023-07-03
409 - Ensure worker queued tasks at error are reassigned to other pool workers.
413 - Add pool `utilization` ratio to pool information.
414 - Add `version` to pool information.
415 - Add worker information to worker nodes.
417 ## [2.6.6] - 2023-07-01
421 - Add safe helper `availableParallelism()` to help sizing the pool.
425 - Ensure message handler is only registered in worker.
427 ## [2.6.5] - 2023-06-27
431 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
435 - Artificial version bump to 2.6.5 to workaround publication issue.
436 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
437 - Ensure pool event is emitted before task error promise rejection.
438 - Fix queued tasks count computation.
442 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
444 ## [2.6.4] - 2023-06-27
448 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
452 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
453 - Ensure pool event is emitted before task error promise rejection.
454 - Fix queued tasks count computation.
458 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
460 ## [2.6.3] - 2023-06-19
464 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
465 - Update strategies internals after statistics computation.
469 - Optimize O(1) queue implementation.
471 ## [2.6.2] - 2023-06-12
475 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
477 ## [2.6.1] - 2023-06-10
481 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
485 - Fix average statistics computation: ensure failed tasks are not accounted.
487 ## [2.6.0] - 2023-06-09
491 - Add `LEAST_ELU` worker choice strategy (experimental).
492 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
496 - Refactor pool worker node usage internals.
497 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
498 - Breaking change: pool information `info` property object fields have been renamed.
502 - Fix wait time accounting.
503 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
504 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
506 ## [2.5.4] - 2023-06-07
510 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
514 - Compute statistics at the worker level only if needed.
515 - Add `worker_threads` options to thread pool options.
519 - Make the `LEAST_BUSY` strategy only relies on task runtime.
521 ## [2.5.3] - 2023-06-04
525 - Refine pool information content.
526 - Limit pool internals public exposure.
528 ## [2.5.2] - 2023-06-02
532 - Add `taskError` pool event for task execution error.
533 - Add pool information `info` property to pool.
534 - Emit pool information on `busy` and `full` pool events.
536 ## [2.5.1] - 2023-06-01
540 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
541 - Add `error` pool event for uncaught worker error.
543 ## [2.5.0] - 2023-05-31
547 - Switch pool event emitter to `EventEmitterAsyncResource`.
548 - Add tasks wait time accounting in per worker tasks usage.
549 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
553 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
555 ## [2.4.14] - 2023-05-09
559 - Ensure no undefined task runtime can land in the tasks history.
560 - Fix median computation implementation once again.
564 - Unit tests for median and queue implementations.
566 ## [2.4.13] - 2023-05-08
570 - Fix worker choice strategy options validation.
571 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
573 ## [2.4.12] - 2023-05-06
577 - Support multiple task functions per worker.
578 - Add custom worker weights support to worker choice strategies options.
582 - Use O(1) queue implementation for tasks queueing.
586 - Fix median computation implementation.
587 - Fix fair share worker choice strategy internals update.
589 ## [2.4.11] - 2023-04-23
593 - Optimize free worker finding in worker choice strategies.
595 ## [2.4.10] - 2023-04-15
599 - Fix typescript type definition for task function: ensure the input data is optional.
600 - Fix typescript type definition for pool execute(): ensure the input data is optional.
602 ## [2.4.9] - 2023-04-15
606 - Add tasks queue enablement runtime setter to pool.
607 - Add tasks queue options runtime setter to pool.
608 - Add worker choice strategy options runtime setter to pool.
612 - Remove the tasks queuing experimental status.
616 - Fix task function type definition and validation.
617 - Fix worker choice strategy options handling.
619 ## [2.4.8] - 2023-04-12
623 - Fix message between main worker and worker type definition for tasks.
624 - Fix code documentation.
626 ## [2.4.7] - 2023-04-11
630 - Add worker tasks queue options to pool options.
634 - Fix missing documentation.
636 ## [2.4.6] - 2023-04-10
640 - Ensure one task at a time is executed per worker with tasks queueing enabled.
641 - Properly count worker executing tasks with tasks queueing enabled.
643 ## [2.4.5] - 2023-04-09
647 - Use monotonic high resolution timer for worker tasks runtime.
648 - Add worker tasks median runtime to statistics.
649 - Add worker tasks queue (experimental).
651 ## [2.4.4] - 2023-04-07
655 - Add `PoolEvents` enumeration and `PoolEvent` type.
659 - Destroy worker only on alive check.
661 ## [2.4.3] - 2023-04-07
665 - Fix typedoc generation with inheritance.
667 ## [2.4.2] - 2023-04-06
671 - Add `full` event to dynamic pool.
672 - Keep worker choice strategy in memory for conditional reuse.
676 - Fix possible negative worker key at worker removal in worker choice strategies.
678 ## [2.4.1] - 2023-04-05
682 - Optimize worker choice strategy for dynamic pool.
686 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
688 ## [2.4.0] - 2023-04-04
692 - Add `LESS_BUSY` worker choice strategy.
696 - Optimize worker storage in pool.
697 - Optimize worker alive status check.
698 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
699 - Optimize `LESS_USED` worker choice strategy.
700 - Update benchmark versus external threads pools.
701 - Optimize tasks usage statistics requirements for worker choice strategy.
705 - Ensure trimmable characters are checked at pool initialization.
706 - Fix message id integer overflow.
707 - Fix pool worker removal in worker choice strategy internals.
708 - Fix package publication with pnpm.
710 ## [2.4.0-3] - 2023-04-04
714 - Add `LESS_BUSY` worker choice strategy.
718 - Optimize worker storage in pool.
719 - Optimize worker alive status check.
720 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
721 - Optimize `LESS_USED` worker choice strategy.
722 - Update benchmark versus external threads pools.
726 - Ensure trimmable characters are checked at pool initialization.
727 - Fix message id integer overflow.
728 - Fix pool worker removal in worker choice strategy internals.
729 - Fix package publication with pnpm.
731 ## [2.4.0-2] - 2023-04-03
735 - Add `LESS_BUSY` worker choice strategy.
739 - Optimize worker storage in pool.
740 - Optimize worker alive status check.
741 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
742 - Optimize `LESS_USED` worker choice strategy.
746 - Ensure trimmable characters are checked at pool initialization.
747 - Fix message id integer overflow.
748 - Fix pool worker removal in worker choice strategy internals.
749 - Fix package publication with pnpm.
751 ## [2.4.0-1] - 2023-04-03
755 - Add `LESS_BUSY` worker choice strategy.
759 - Optimize worker storage in pool.
760 - Optimize worker alive status check.
761 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
762 - Optimize `LESS_USED` worker choice strategy.
766 - Ensure trimmable characters are checked at pool initialization.
767 - Fix message id integer overflow.
768 - Fix pool worker removal in worker choice strategy internals.
770 ## [2.4.0-0] - 2023-04-03
774 - Add `LESS_BUSY` worker choice strategy.
778 - Optimize worker storage in pool.
779 - Optimize worker alive status check.
780 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
781 - Optimize `LESS_USED` worker choice strategy.
785 - Ensure trimmable characters are checked at pool initialization.
786 - Fix message id integer overflow.
787 - Fix pool worker removal in worker choice strategy internals.
789 ## [2.3.10] - 2023-03-18
793 - Fix package.json `exports` syntax for ESM and CommonJS.
797 - Permit SemVer pre-release publication.
799 ## [2.3.10-2] - 2023-03-18
803 - Fix package.json `exports` syntax for ESM and CommonJS.
805 ## [2.3.10-1] - 2023-03-18
809 - Permit SemVer pre-release publication.
811 ## [2.3.10-0] - 2023-03-18
815 - Fix package.json `exports` syntax for ESM and CommonJS.
817 ## [2.3.9] - 2023-03-18
821 - Introduce ESM module support along with CommonJS one.
825 - Fix brown paper bag bug referencing the same object literal.
827 ## [2.3.8] - 2023-03-18
831 - Switch internal benchmarking code to benny.
832 - Switch to TypeScript 5.x.x.
833 - Switch rollup bundler plugins to core ones.
834 - Switch to TSDoc syntax.
835 - Enforce conventional commits.
839 - Fix random integer generator.
840 - Fix worker choice strategy pool type identification at initialization.
842 ## [2.3.7] - 2022-10-23
846 - Switch to open collective FOSS project funding platform.
847 - Switch to ts-standard linter configuration on TypeScript code.
851 - Fixed missing async on pool execute method.
852 - Fixed typing in TypeScript example.
853 - Fixed types in unit tests.
855 ## [2.3.6] - 2022-10-22
859 - Cleanup pool attributes and methods.
860 - Refine error types thrown.
864 - Fix continuous integration build on windows.
865 - Fix code coverage reporting by using c8 instead of nyc.
867 ## [2.3.5] - 2022-10-21
871 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
872 - Optimize tasks usage lookup implementation.
876 - Fix missed pool event emitter type export.
877 - Fix typedoc documentation generation.
879 ## [2.3.4] - 2022-10-17
883 - Fully automate release process with release-it.
887 - Optimize fair share task scheduling algorithm implementation.
888 - Update benchmark versus external pools results with latest version.
890 ## [2.3.3] - 2022-10-15
894 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
896 ## [2.3.2] - 2022-10-14
900 - Optimize fair share worker selection strategy implementation.
904 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
906 ## [2.3.1] - 2022-10-13
910 - Pool worker choice strategies:
911 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
912 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
914 ## [2.2.2] - 2022-10-09
918 - Fixed `README.md` file.
920 ## [2.2.1] - 2022-10-08
924 - Dynamic worker choice strategy change at runtime.
926 ## [2.2.0] - 2022-01-05
930 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
932 ## [2.1.0] - 2021-08-29
936 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
940 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
941 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
942 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
943 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
945 ## [2.0.2] - 2021-05-12
949 - Fix `busy` event emission on fixed pool type
951 ## [2.0.1] - 2021-03-16
955 - Check if pool options are properly set.
956 - `busy` event is emitted on all pool types.
958 ## [2.0.0] - 2021-03-01
962 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
966 - `FullPool` event is now renamed to `busy`.
967 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
968 _Find more details on our JSDoc._
970 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
972 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
974 ### Pool options types declaration merge
976 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
978 #### New `export` strategy
982 const DynamicThreadPool = require('poolifier/lib/dynamic')
984 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
987 But you should always prefer just using
990 const { DynamicThreadPool } = require('poolifier')
993 #### New type definitions for input data and response
995 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
996 _This is not a limitation by poolifier but Node.js._
998 #### Public property replacements
1000 `numWorkers` property is now `numberOfWorkers`
1002 #### Internal (protected) properties and methods renaming
1004 These properties are not intended for end users
1006 - `id` => `nextMessageId`
1008 These methods are not intended for end users
1010 - `_chooseWorker` => `chooseWorker`
1011 - `_newWorker` => `createWorker`
1012 - `_execute` => `internalExecute`
1013 - `_chooseWorker` => `chooseWorker`
1014 - `_checkAlive` => `checkAlive`
1016 - `_runAsync` => `runAsync`
1018 ## [1.1.0] - 2020-05-21
1022 - ThreadWorker support async functions as option
1023 - Various external library patches
1025 ## [1.0.0] - 2020-01-24
1029 - FixedThreadPool implementation
1030 - DynamicThreadPool implementation
1031 - WorkerThread implementation to improve developer experience