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 ## [2.7.2] - 2023-09-23
14 - Add source maps to npm package to ease debugging.
18 - Continuous benchmarking versus other worker pools: [https://poolifier.github.io/benchmark](https://poolifier.github.io/benchmark).
20 ## [2.7.1] - 2023-09-20
24 - Ensure worker message listener used one time are removed after usage.
26 ## [2.7.0] - 2023-09-19
30 - Fix task stealing related tasks queue options handling at runtime.
34 - Rename `listTaskFunctions()` to `listTaskFunctionNames()` in pool and worker API.
38 - Add `hasTaskFunction()`, `addTaskFunction()`, `removeTaskFunction()`, `setDefaultTaskFunction()` methods to pool API: [PR #1148](https://github.com/poolifier/poolifier/pull/1148).
39 - Stricter worker constructor arguments validation.
41 ## [2.6.45] - 2023-09-17
45 - Disable publication on GitHub packages registry on release until authentication issue is fixed.
49 - Add `startWorkers` to pool options to whether start the minimum number of workers at pool creation or not.
50 - Add `start()` method to pool API to start the minimum number of workers.
51 - 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.
52 - Continuous internal benchmarking: [https://poolifier.github.io/benchmark-results/dev/bench](https://poolifier.github.io/benchmark-results/dev/bench).
54 ## [2.6.44] - 2023-09-08
58 - Use a dedicated PAT to publish on GitHub packages registry.
62 - Publish on GitHub packages registry on release.
66 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
68 ## [2.6.43] - 2023-09-08
72 - Publish on GitHub packages registry on release.
76 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
78 ## [2.6.42] - 2023-09-06
82 - Optimize hot code paths implementation: avoid unnecessary branching, add and use optimized helpers (min, max), use reduce() array helper, ...
84 ## [2.6.41] - 2023-09-03
88 - Optimize worker choice strategies implementation.
90 ## [2.6.40] - 2023-09-01
94 - Do not pre-choose in WRR worker choice strategy to avoid bias.
95 - Avoid array out of bound in worker choice strategies after worker node removal.
97 ## [2.6.39] - 2023-08-30
101 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized.
103 ## [2.6.38] - 2023-08-30
107 - Bundle typescript types declaration into one file.
111 - Improve interleaved weighted round robin worker choice strategy implementation.
113 ## [2.6.37] - 2023-08-28
117 - Ensure unused worker usage statistics are deleted at runtime.
121 - Rename worker choice strategy options `choiceRetries` to `retries`.
122 - Avoid unnecessary branching in worker choice strategies.
124 ## [2.6.36] - 2023-08-27
128 - Fix pool `execute()` arguments check.
132 - Make continuous tasks stealing algorithm less aggressive.
133 - Fine tune tasks stealing algorithm under back pressure.
135 ## [2.6.35] - 2023-08-25
139 - Don't account worker usage statistics for tasks that have failed.
140 - Fix pool information runtime and wait time median computation.
144 - Update simple moving average implementation to use a circular buffer.
145 - Update simple moving median implementation to use a circular buffer.
146 - Account for stolen tasks in worker usage statistics and pool information.
150 - Continuous tasks stealing algorithm.
152 ## [2.6.34] - 2023-08-24
156 - Avoid cascading tasks stealing under back pressure.
160 - Add fastpath to queued tasks rescheduling.
162 ## [2.6.33] - 2023-08-24
166 - Fix queued tasks rescheduling.
170 - Rename tasks queue options `queueMaxSize` to `size`.
174 - Task stealing scheduling algorithm if tasks queueing is enabled.
176 ## [2.6.32] - 2023-08-23
180 - Ensure no task can be executed when the pool is destroyed.
184 - Add `queueMaxSize` option to tasks queue options.
185 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
186 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
188 ## [2.6.31] - 2023-08-20
192 - Fix worker choice strategy retries mechanism in some edge cases.
196 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
197 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
199 ## [2.6.30] - 2023-08-19
203 - Ensure pool event `backPressure` is emitted.
204 - Ensure pool event `full` is emitted only once.
205 - Ensure worker node cannot be instantiated without proper arguments.
207 ## [2.6.29] - 2023-08-18
211 - Fix race condition between ready and task functions worker message handling at startup.
212 - Fix duplicate task function worker usage statistics computation per task function.
213 - Update task function worker usage statistics if and only if there's at least two different task functions.
214 - Fix race condition at task function worker usage executing task computation leading to negative value.
218 - 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).
219 - Use back pressure detection in worker choice strategies.
220 - Add worker choice strategies retries mechanism if no worker is eligible.
222 ## [2.6.28] - 2023-08-16
226 - Ensure pool workers are properly initialized.
230 - HTTP server pool examples: express-cluster, express-hybrid.
234 - Remove now useless branching in worker hot code path.
236 ## [2.6.27] - 2023-08-15
240 - Add `KillHandler` type definition to exported types.
244 - Add `destroy` event to pool API.
246 ## [2.6.26] - 2023-08-15
250 - Add kill handler to worker options allowing to execute custom code when worker is killed.
251 - Add `listTaskFunctions()` method to pool API.
252 - SMTP client pool example: nodemailer.
254 ## [2.6.25] - 2023-08-13
258 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
259 - WebSocket server pool examples: ws-cluster, ws-hybrid.
261 ## [2.6.24] - 2023-08-12
265 - Add array of transferable objects to the `execute()` method arguments.
266 - WebSocket server pool examples: ws-worker_threads.
268 ## [2.6.23] - 2023-08-11
272 - 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.
276 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
277 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
279 ## [2.6.22] - 2023-08-10
283 - Add missing `types` field to package.json `exports`.
287 - Structure markdown documentation (PR #811).
289 ## [2.6.21] - 2023-08-03
293 - Improve code documentation.
294 - Code refactoring and cleanup for better maintainability and readability.
296 ## [2.6.20] - 2023-07-21
300 - Fix queued tasks redistribution on error task execution starvation.
301 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
305 - Drastically reduce lookups by worker in the worker nodes.
307 ## [2.6.19] - 2023-07-20
311 - Dedicated internal communication channel for worker_threads pools.
313 ## [2.6.18] - 2023-07-19
317 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
319 ## [2.6.17] - 2023-07-16
323 - Add `listTaskFunctions()` method to worker API.
325 ## [2.6.16] - 2023-07-12
329 - Fix pool startup detection.
330 - Fix worker task functions handling.
332 ## [2.6.15] - 2023-07-11
336 - Take into account worker node readiness in worker choice strategies.
338 ## [2.6.14] - 2023-07-10
342 - Fix task function statistics tracking.
344 ## [2.6.13] - 2023-07-10
348 - Add per task function statistics tracking.
349 - Add public methods to manipulate the worker task functions at runtime.
351 ## [2.6.12] - 2023-07-09
355 - Workaround import issue with `node:os` module in node 16.x.x.
357 ## [2.6.11] - 2023-07-09
361 - Fix pool readiness semantic.
363 ## [2.6.10] - 2023-07-08
367 - Ensure workers are not recreated on error at pool startup.
371 - Add `ready` and `strategy` fields to pool information.
372 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
373 - Add dynamic pool sizing checks.
375 ## [2.6.9] - 2023-07-07
379 - Recreate the right worker type on uncaught exception.
383 - Add minimum and maximum to internal measurement statistics.
384 - Add `runTime` and `waitTime` to pool information.
385 - Check worker inactive time only on dynamic worker.
387 ## [2.6.8] - 2023-07-03
391 - Brown paper bag release to fix version handling in pool information.
393 ## [2.6.7] - 2023-07-03
397 - Ensure worker queued tasks at error are reassigned to other pool workers.
401 - Add pool `utilization` ratio to pool information.
402 - Add `version` to pool information.
403 - Add worker information to worker nodes.
405 ## [2.6.6] - 2023-07-01
409 - Add safe helper `availableParallelism()` to help sizing the pool.
413 - Ensure message handler is only registered in worker.
415 ## [2.6.5] - 2023-06-27
419 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
423 - Artificial version bump to 2.6.5 to workaround publication issue.
424 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
425 - Ensure pool event is emitted before task error promise rejection.
426 - Fix queued tasks count computation.
430 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
432 ## [2.6.4] - 2023-06-27
436 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
440 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
441 - Ensure pool event is emitted before task error promise rejection.
442 - Fix queued tasks count computation.
446 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
448 ## [2.6.3] - 2023-06-19
452 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
453 - Update strategies internals after statistics computation.
457 - Optimize O(1) queue implementation.
459 ## [2.6.2] - 2023-06-12
463 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
465 ## [2.6.1] - 2023-06-10
469 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
473 - Fix average statistics computation: ensure failed tasks are not accounted.
475 ## [2.6.0] - 2023-06-09
479 - Add `LEAST_ELU` worker choice strategy (experimental).
480 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
484 - Refactor pool worker node usage internals.
485 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
486 - Breaking change: pool information `info` property object fields have been renamed.
490 - Fix wait time accounting.
491 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
492 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
494 ## [2.5.4] - 2023-06-07
498 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
502 - Compute statistics at the worker level only if needed.
503 - Add `worker_threads` options to thread pool options.
507 - Make the `LEAST_BUSY` strategy only relies on task runtime.
509 ## [2.5.3] - 2023-06-04
513 - Refine pool information content.
514 - Limit pool internals public exposure.
516 ## [2.5.2] - 2023-06-02
520 - Add `taskError` pool event for task execution error.
521 - Add pool information `info` property to pool.
522 - Emit pool information on `busy` and `full` pool events.
524 ## [2.5.1] - 2023-06-01
528 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
529 - Add `error` pool event for uncaught worker error.
531 ## [2.5.0] - 2023-05-31
535 - Switch pool event emitter to `EventEmitterAsyncResource`.
536 - Add tasks wait time accounting in per worker tasks usage.
537 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
541 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
543 ## [2.4.14] - 2023-05-09
547 - Ensure no undefined task runtime can land in the tasks history.
548 - Fix median computation implementation once again.
552 - Unit tests for median and queue implementations.
554 ## [2.4.13] - 2023-05-08
558 - Fix worker choice strategy options validation.
559 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
561 ## [2.4.12] - 2023-05-06
565 - Support multiple task functions per worker.
566 - Add custom worker weights support to worker choice strategies options.
570 - Use O(1) queue implementation for tasks queueing.
574 - Fix median computation implementation.
575 - Fix fair share worker choice strategy internals update.
577 ## [2.4.11] - 2023-04-23
581 - Optimize free worker finding in worker choice strategies.
583 ## [2.4.10] - 2023-04-15
587 - Fix typescript type definition for task function: ensure the input data is optional.
588 - Fix typescript type definition for pool execute(): ensure the input data is optional.
590 ## [2.4.9] - 2023-04-15
594 - Add tasks queue enablement runtime setter to pool.
595 - Add tasks queue options runtime setter to pool.
596 - Add worker choice strategy options runtime setter to pool.
600 - Remove the tasks queuing experimental status.
604 - Fix task function type definition and validation.
605 - Fix worker choice strategy options handling.
607 ## [2.4.8] - 2023-04-12
611 - Fix message between main worker and worker type definition for tasks.
612 - Fix code documentation.
614 ## [2.4.7] - 2023-04-11
618 - Add worker tasks queue options to pool options.
622 - Fix missing documentation.
624 ## [2.4.6] - 2023-04-10
628 - Ensure one task at a time is executed per worker with tasks queueing enabled.
629 - Properly count worker executing tasks with tasks queueing enabled.
631 ## [2.4.5] - 2023-04-09
635 - Use monotonic high resolution timer for worker tasks runtime.
636 - Add worker tasks median runtime to statistics.
637 - Add worker tasks queue (experimental).
639 ## [2.4.4] - 2023-04-07
643 - Add `PoolEvents` enumeration and `PoolEvent` type.
647 - Destroy worker only on alive check.
649 ## [2.4.3] - 2023-04-07
653 - Fix typedoc generation with inheritance.
655 ## [2.4.2] - 2023-04-06
659 - Add `full` event to dynamic pool.
660 - Keep worker choice strategy in memory for conditional reuse.
664 - Fix possible negative worker key at worker removal in worker choice strategies.
666 ## [2.4.1] - 2023-04-05
670 - Optimize worker choice strategy for dynamic pool.
674 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
676 ## [2.4.0] - 2023-04-04
680 - Add `LESS_BUSY` worker choice strategy.
684 - Optimize worker storage in pool.
685 - Optimize worker alive status check.
686 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
687 - Optimize `LESS_USED` worker choice strategy.
688 - Update benchmark versus external threads pools.
689 - Optimize tasks usage statistics requirements for worker choice strategy.
693 - Ensure trimmable characters are checked at pool initialization.
694 - Fix message id integer overflow.
695 - Fix pool worker removal in worker choice strategy internals.
696 - Fix package publication with pnpm.
698 ## [2.4.0-3] - 2023-04-04
702 - Add `LESS_BUSY` worker choice strategy.
706 - Optimize worker storage in pool.
707 - Optimize worker alive status check.
708 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
709 - Optimize `LESS_USED` worker choice strategy.
710 - Update benchmark versus external threads pools.
714 - Ensure trimmable characters are checked at pool initialization.
715 - Fix message id integer overflow.
716 - Fix pool worker removal in worker choice strategy internals.
717 - Fix package publication with pnpm.
719 ## [2.4.0-2] - 2023-04-03
723 - Add `LESS_BUSY` worker choice strategy.
727 - Optimize worker storage in pool.
728 - Optimize worker alive status check.
729 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
730 - Optimize `LESS_USED` worker choice strategy.
734 - Ensure trimmable characters are checked at pool initialization.
735 - Fix message id integer overflow.
736 - Fix pool worker removal in worker choice strategy internals.
737 - Fix package publication with pnpm.
739 ## [2.4.0-1] - 2023-04-03
743 - Add `LESS_BUSY` worker choice strategy.
747 - Optimize worker storage in pool.
748 - Optimize worker alive status check.
749 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
750 - Optimize `LESS_USED` worker choice strategy.
754 - Ensure trimmable characters are checked at pool initialization.
755 - Fix message id integer overflow.
756 - Fix pool worker removal in worker choice strategy internals.
758 ## [2.4.0-0] - 2023-04-03
762 - Add `LESS_BUSY` worker choice strategy.
766 - Optimize worker storage in pool.
767 - Optimize worker alive status check.
768 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
769 - Optimize `LESS_USED` worker choice strategy.
773 - Ensure trimmable characters are checked at pool initialization.
774 - Fix message id integer overflow.
775 - Fix pool worker removal in worker choice strategy internals.
777 ## [2.3.10] - 2023-03-18
781 - Fix package.json `exports` syntax for ESM and CommonJS.
785 - Permit SemVer pre-release publication.
787 ## [2.3.10-2] - 2023-03-18
791 - Fix package.json `exports` syntax for ESM and CommonJS.
793 ## [2.3.10-1] - 2023-03-18
797 - Permit SemVer pre-release publication.
799 ## [2.3.10-0] - 2023-03-18
803 - Fix package.json `exports` syntax for ESM and CommonJS.
805 ## [2.3.9] - 2023-03-18
809 - Introduce ESM module support along with CommonJS one.
813 - Fix brown paper bag bug referencing the same object literal.
815 ## [2.3.8] - 2023-03-18
819 - Switch internal benchmarking code to benny.
820 - Switch to TypeScript 5.x.x.
821 - Switch rollup bundler plugins to core ones.
822 - Switch to TSDoc syntax.
823 - Enforce conventional commits.
827 - Fix random integer generator.
828 - Fix worker choice strategy pool type identification at initialization.
830 ## [2.3.7] - 2022-10-23
834 - Switch to open collective FOSS project funding platform.
835 - Switch to ts-standard linter configuration on TypeScript code.
839 - Fixed missing async on pool execute method.
840 - Fixed typing in TypeScript example.
841 - Fixed types in unit tests.
843 ## [2.3.6] - 2022-10-22
847 - Cleanup pool attributes and methods.
848 - Refine error types thrown.
852 - Fix continuous integration build on windows.
853 - Fix code coverage reporting by using c8 instead of nyc.
855 ## [2.3.5] - 2022-10-21
859 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
860 - Optimize tasks usage lookup implementation.
864 - Fix missed pool event emitter type export.
865 - Fix typedoc documentation generation.
867 ## [2.3.4] - 2022-10-17
871 - Fully automate release process with release-it.
875 - Optimize fair share task scheduling algorithm implementation.
876 - Update benchmark versus external pools results with latest version.
878 ## [2.3.3] - 2022-10-15
882 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
884 ## [2.3.2] - 2022-10-14
888 - Optimize fair share worker selection strategy implementation.
892 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
894 ## [2.3.1] - 2022-10-13
898 - Pool worker choice strategies:
899 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
900 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
902 ## [2.2.2] - 2022-10-09
906 - Fixed `README.md` file.
908 ## [2.2.1] - 2022-10-08
912 - Dynamic worker choice strategy change at runtime.
914 ## [2.2.0] - 2022-01-05
918 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
920 ## [2.1.0] - 2021-08-29
924 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
928 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
929 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
930 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
931 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
933 ## [2.0.2] - 2021-05-12
937 - Fix `busy` event emission on fixed pool type
939 ## [2.0.1] - 2021-03-16
943 - Check if pool options are properly set.
944 - `busy` event is emitted on all pool types.
946 ## [2.0.0] - 2021-03-01
950 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
954 - `FullPool` event is now renamed to `busy`.
955 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
956 _Find more details on our JSDoc._
958 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
960 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
962 ### Pool options types declaration merge
964 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
966 #### New `export` strategy
970 const DynamicThreadPool = require('poolifier/lib/dynamic')
972 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
975 But you should always prefer just using
978 const { DynamicThreadPool } = require('poolifier')
981 #### New type definitions for input data and response
983 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
984 _This is not a limitation by poolifier but Node.js._
986 #### Public property replacements
988 `numWorkers` property is now `numberOfWorkers`
990 #### Internal (protected) properties and methods renaming
992 These properties are not intended for end users
994 - `id` => `nextMessageId`
996 These methods are not intended for end users
998 - `_chooseWorker` => `chooseWorker`
999 - `_newWorker` => `createWorker`
1000 - `_execute` => `internalExecute`
1001 - `_chooseWorker` => `chooseWorker`
1002 - `_checkAlive` => `checkAlive`
1004 - `_runAsync` => `runAsync`
1006 ## [1.1.0] - 2020-05-21
1010 - ThreadWorker support async functions as option
1011 - Various external library patches
1013 ## [1.0.0] - 2020-01-24
1017 - FixedThreadPool implementation
1018 - DynamicThreadPool implementation
1019 - WorkerThread implementation to improve developer experience