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 ## [3.0.0] - 2023-10-08
14 - Remove Node.js 16.x.x (EOL) support.
16 ## [2.7.5] - 2023-10-03
20 - Use `EventEmitterAsyncResource` type from `@types/node` for pool event emitter. TypeScript users will need to update to latest `@types/node` version.
22 ## [2.7.4] - 2023-09-25
26 - Fix source maps (bundler issue).
28 ## [2.7.3] - 2023-09-24
32 - Convert pool event emitter to event emitter async resource.
34 ## [2.7.2] - 2023-09-23
38 - Add source maps to npm package to ease debugging.
42 - Continuous benchmarking versus other worker pools: [https://poolifier.github.io/benchmark](https://poolifier.github.io/benchmark).
44 ## [2.7.1] - 2023-09-20
48 - Ensure worker message listener used one time are removed after usage.
50 ## [2.7.0] - 2023-09-19
54 - Fix task stealing related tasks queue options handling at runtime.
58 - Rename `listTaskFunctions()` to `listTaskFunctionNames()` in pool and worker API.
62 - Add `hasTaskFunction()`, `addTaskFunction()`, `removeTaskFunction()`, `setDefaultTaskFunction()` methods to pool API: [PR #1148](https://github.com/poolifier/poolifier/pull/1148).
63 - Stricter worker constructor arguments validation.
65 ## [2.6.45] - 2023-09-17
69 - Disable publication on GitHub packages registry on release until authentication issue is fixed.
73 - Add `startWorkers` to pool options to whether start the minimum number of workers at pool initialization or not.
74 - Add `start()` method to pool API to start the minimum number of workers.
75 - Add `taskStealing` and `tasksStealingOnPressure` to tasks queue options to whether enable task stealing or not and whether enable tasks stealing under back pressure or not.
76 - Continuous internal benchmarking: [https://poolifier.github.io/benchmark-results/dev/bench](https://poolifier.github.io/benchmark-results/dev/bench).
78 ## [2.6.44] - 2023-09-08
82 - Use a dedicated PAT to publish on GitHub packages registry.
86 - Publish on GitHub packages registry on release.
90 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
92 ## [2.6.43] - 2023-09-08
96 - Publish on GitHub packages registry on release.
100 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
102 ## [2.6.42] - 2023-09-06
106 - Optimize hot code paths implementation: avoid unnecessary branching, add and use optimized helpers (min, max), use reduce() array helper, ...
108 ## [2.6.41] - 2023-09-03
112 - Optimize worker choice strategies implementation.
114 ## [2.6.40] - 2023-09-01
118 - Do not pre-choose in WRR worker choice strategy to avoid bias.
119 - Avoid array out of bound in worker choice strategies after worker node removal.
121 ## [2.6.39] - 2023-08-30
125 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized.
127 ## [2.6.38] - 2023-08-30
131 - Bundle typescript types declaration into one file.
135 - Improve interleaved weighted round robin worker choice strategy implementation.
137 ## [2.6.37] - 2023-08-28
141 - Ensure unused worker usage statistics are deleted at runtime.
145 - Rename worker choice strategy options `choiceRetries` to `retries`.
146 - Avoid unnecessary branching in worker choice strategies.
148 ## [2.6.36] - 2023-08-27
152 - Fix pool `execute()` arguments check.
156 - Make continuous tasks stealing algorithm less aggressive.
157 - Fine tune tasks stealing algorithm under back pressure.
159 ## [2.6.35] - 2023-08-25
163 - Don't account worker usage statistics for tasks that have failed.
164 - Fix pool information runtime and wait time median computation.
168 - Update simple moving average implementation to use a circular buffer.
169 - Update simple moving median implementation to use a circular buffer.
170 - Account for stolen tasks in worker usage statistics and pool information.
174 - Continuous tasks stealing algorithm.
176 ## [2.6.34] - 2023-08-24
180 - Avoid cascading tasks stealing under back pressure.
184 - Add fastpath to queued tasks rescheduling.
186 ## [2.6.33] - 2023-08-24
190 - Fix queued tasks rescheduling.
194 - Rename tasks queue options `queueMaxSize` to `size`.
198 - Task stealing scheduling algorithm if tasks queueing is enabled.
200 ## [2.6.32] - 2023-08-23
204 - Ensure no task can be executed when the pool is destroyed.
208 - Add `queueMaxSize` option to tasks queue options.
209 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
210 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
212 ## [2.6.31] - 2023-08-20
216 - Fix worker choice strategy retries mechanism in some edge cases.
220 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
221 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
223 ## [2.6.30] - 2023-08-19
227 - Ensure pool event `backPressure` is emitted.
228 - Ensure pool event `full` is emitted only once.
229 - Ensure worker node cannot be instantiated without proper arguments.
231 ## [2.6.29] - 2023-08-18
235 - Fix race condition between ready and task functions worker message handling at startup.
236 - Fix duplicate task function worker usage statistics computation per task function.
237 - Update task function worker usage statistics if and only if there's at least two different task functions.
238 - Fix race condition at task function worker usage executing task computation leading to negative value.
242 - 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).
243 - Use back pressure detection in worker choice strategies.
244 - Add worker choice strategies retries mechanism if no worker is eligible.
246 ## [2.6.28] - 2023-08-16
250 - Ensure pool workers are properly initialized.
254 - HTTP server pool examples: express-cluster, express-hybrid.
258 - Remove now useless branching in worker hot code path.
260 ## [2.6.27] - 2023-08-15
264 - Add `KillHandler` type definition to exported types.
268 - Add `destroy` event to pool API.
270 ## [2.6.26] - 2023-08-15
274 - Add kill handler to worker options allowing to execute custom code when worker is killed.
275 - Add `listTaskFunctions()` method to pool API.
276 - SMTP client pool example: nodemailer.
278 ## [2.6.25] - 2023-08-13
282 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
283 - WebSocket server pool examples: ws-cluster, ws-hybrid.
285 ## [2.6.24] - 2023-08-12
289 - Add array of transferable objects to the `execute()` method arguments.
290 - WebSocket server pool examples: ws-worker_threads.
292 ## [2.6.23] - 2023-08-11
296 - 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.
300 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
301 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
303 ## [2.6.22] - 2023-08-10
307 - Add missing `types` field to package.json `exports`.
311 - Structure markdown documentation (PR #811).
313 ## [2.6.21] - 2023-08-03
317 - Improve code documentation.
318 - Code refactoring and cleanup for better maintainability and readability.
320 ## [2.6.20] - 2023-07-21
324 - Fix queued tasks redistribution on error task execution starvation.
325 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
329 - Drastically reduce lookups by worker in the worker nodes.
331 ## [2.6.19] - 2023-07-20
335 - Dedicated internal communication channel for worker_threads pools.
337 ## [2.6.18] - 2023-07-19
341 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
343 ## [2.6.17] - 2023-07-16
347 - Add `listTaskFunctions()` method to worker API.
349 ## [2.6.16] - 2023-07-12
353 - Fix pool startup detection.
354 - Fix worker task functions handling.
356 ## [2.6.15] - 2023-07-11
360 - Take into account worker node readiness in worker choice strategies.
362 ## [2.6.14] - 2023-07-10
366 - Fix task function statistics tracking.
368 ## [2.6.13] - 2023-07-10
372 - Add per task function statistics tracking.
373 - Add public methods to manipulate the worker task functions at runtime.
375 ## [2.6.12] - 2023-07-09
379 - Workaround import issue with `node:os` module in node 16.x.x.
381 ## [2.6.11] - 2023-07-09
385 - Fix pool readiness semantic.
387 ## [2.6.10] - 2023-07-08
391 - Ensure workers are not recreated on error at pool startup.
395 - Add `ready` and `strategy` fields to pool information.
396 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
397 - Add dynamic pool sizing checks.
399 ## [2.6.9] - 2023-07-07
403 - Recreate the right worker type on uncaught exception.
407 - Add minimum and maximum to internal measurement statistics.
408 - Add `runTime` and `waitTime` to pool information.
409 - Check worker inactive time only on dynamic worker.
411 ## [2.6.8] - 2023-07-03
415 - Brown paper bag release to fix version handling in pool information.
417 ## [2.6.7] - 2023-07-03
421 - Ensure worker queued tasks at error are reassigned to other pool workers.
425 - Add pool `utilization` ratio to pool information.
426 - Add `version` to pool information.
427 - Add worker information to worker nodes.
429 ## [2.6.6] - 2023-07-01
433 - Add safe helper `availableParallelism()` to help sizing the pool.
437 - Ensure message handler is only registered in worker.
439 ## [2.6.5] - 2023-06-27
443 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
447 - Artificial version bump to 2.6.5 to workaround publication issue.
448 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
449 - Ensure pool event is emitted before task error promise rejection.
450 - Fix queued tasks count computation.
454 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
456 ## [2.6.4] - 2023-06-27
460 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
464 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
465 - Ensure pool event is emitted before task error promise rejection.
466 - Fix queued tasks count computation.
470 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
472 ## [2.6.3] - 2023-06-19
476 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
477 - Update strategies internals after statistics computation.
481 - Optimize O(1) queue implementation.
483 ## [2.6.2] - 2023-06-12
487 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
489 ## [2.6.1] - 2023-06-10
493 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
497 - Fix average statistics computation: ensure failed tasks are not accounted.
499 ## [2.6.0] - 2023-06-09
503 - Add `LEAST_ELU` worker choice strategy (experimental).
504 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
508 - Refactor pool worker node usage internals.
509 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
510 - Breaking change: pool information `info` property object fields have been renamed.
514 - Fix wait time accounting.
515 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
516 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
518 ## [2.5.4] - 2023-06-07
522 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
526 - Compute statistics at the worker level only if needed.
527 - Add `worker_threads` options to thread pool options.
531 - Make the `LEAST_BUSY` strategy only relies on task runtime.
533 ## [2.5.3] - 2023-06-04
537 - Refine pool information content.
538 - Limit pool internals public exposure.
540 ## [2.5.2] - 2023-06-02
544 - Add `taskError` pool event for task execution error.
545 - Add pool information `info` property to pool.
546 - Emit pool information on `busy` and `full` pool events.
548 ## [2.5.1] - 2023-06-01
552 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
553 - Add `error` pool event for uncaught worker error.
555 ## [2.5.0] - 2023-05-31
559 - Switch pool event emitter to `EventEmitterAsyncResource`.
560 - Add tasks wait time accounting in per worker tasks usage.
561 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
565 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
567 ## [2.4.14] - 2023-05-09
571 - Ensure no undefined task runtime can land in the tasks history.
572 - Fix median computation implementation once again.
576 - Unit tests for median and queue implementations.
578 ## [2.4.13] - 2023-05-08
582 - Fix worker choice strategy options validation.
583 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
585 ## [2.4.12] - 2023-05-06
589 - Support multiple task functions per worker.
590 - Add custom worker weights support to worker choice strategies options.
594 - Use O(1) queue implementation for tasks queueing.
598 - Fix median computation implementation.
599 - Fix fair share worker choice strategy internals update.
601 ## [2.4.11] - 2023-04-23
605 - Optimize free worker finding in worker choice strategies.
607 ## [2.4.10] - 2023-04-15
611 - Fix typescript type definition for task function: ensure the input data is optional.
612 - Fix typescript type definition for pool execute(): ensure the input data is optional.
614 ## [2.4.9] - 2023-04-15
618 - Add tasks queue enablement runtime setter to pool.
619 - Add tasks queue options runtime setter to pool.
620 - Add worker choice strategy options runtime setter to pool.
624 - Remove the tasks queuing experimental status.
628 - Fix task function type definition and validation.
629 - Fix worker choice strategy options handling.
631 ## [2.4.8] - 2023-04-12
635 - Fix message between main worker and worker type definition for tasks.
636 - Fix code documentation.
638 ## [2.4.7] - 2023-04-11
642 - Add worker tasks queue options to pool options.
646 - Fix missing documentation.
648 ## [2.4.6] - 2023-04-10
652 - Ensure one task at a time is executed per worker with tasks queueing enabled.
653 - Properly count worker executing tasks with tasks queueing enabled.
655 ## [2.4.5] - 2023-04-09
659 - Use monotonic high resolution timer for worker tasks runtime.
660 - Add worker tasks median runtime to statistics.
661 - Add worker tasks queue (experimental).
663 ## [2.4.4] - 2023-04-07
667 - Add `PoolEvents` enumeration and `PoolEvent` type.
671 - Destroy worker only on alive check.
673 ## [2.4.3] - 2023-04-07
677 - Fix typedoc generation with inheritance.
679 ## [2.4.2] - 2023-04-06
683 - Add `full` event to dynamic pool.
684 - Keep worker choice strategy in memory for conditional reuse.
688 - Fix possible negative worker key at worker removal in worker choice strategies.
690 ## [2.4.1] - 2023-04-05
694 - Optimize worker choice strategy for dynamic pool.
698 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
700 ## [2.4.0] - 2023-04-04
704 - Add `LESS_BUSY` worker choice strategy.
708 - Optimize worker storage in pool.
709 - Optimize worker alive status check.
710 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
711 - Optimize `LESS_USED` worker choice strategy.
712 - Update benchmark versus external threads pools.
713 - Optimize tasks usage statistics requirements for worker choice strategy.
717 - Ensure trimmable characters are checked at pool initialization.
718 - Fix message id integer overflow.
719 - Fix pool worker removal in worker choice strategy internals.
720 - Fix package publication with pnpm.
722 ## [2.4.0-3] - 2023-04-04
726 - Add `LESS_BUSY` worker choice strategy.
730 - Optimize worker storage in pool.
731 - Optimize worker alive status check.
732 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
733 - Optimize `LESS_USED` worker choice strategy.
734 - Update benchmark versus external threads pools.
738 - Ensure trimmable characters are checked at pool initialization.
739 - Fix message id integer overflow.
740 - Fix pool worker removal in worker choice strategy internals.
741 - Fix package publication with pnpm.
743 ## [2.4.0-2] - 2023-04-03
747 - Add `LESS_BUSY` worker choice strategy.
751 - Optimize worker storage in pool.
752 - Optimize worker alive status check.
753 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
754 - Optimize `LESS_USED` worker choice strategy.
758 - Ensure trimmable characters are checked at pool initialization.
759 - Fix message id integer overflow.
760 - Fix pool worker removal in worker choice strategy internals.
761 - Fix package publication with pnpm.
763 ## [2.4.0-1] - 2023-04-03
767 - Add `LESS_BUSY` worker choice strategy.
771 - Optimize worker storage in pool.
772 - Optimize worker alive status check.
773 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
774 - Optimize `LESS_USED` worker choice strategy.
778 - Ensure trimmable characters are checked at pool initialization.
779 - Fix message id integer overflow.
780 - Fix pool worker removal in worker choice strategy internals.
782 ## [2.4.0-0] - 2023-04-03
786 - Add `LESS_BUSY` worker choice strategy.
790 - Optimize worker storage in pool.
791 - Optimize worker alive status check.
792 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
793 - Optimize `LESS_USED` worker choice strategy.
797 - Ensure trimmable characters are checked at pool initialization.
798 - Fix message id integer overflow.
799 - Fix pool worker removal in worker choice strategy internals.
801 ## [2.3.10] - 2023-03-18
805 - Fix package.json `exports` syntax for ESM and CommonJS.
809 - Permit SemVer pre-release publication.
811 ## [2.3.10-2] - 2023-03-18
815 - Fix package.json `exports` syntax for ESM and CommonJS.
817 ## [2.3.10-1] - 2023-03-18
821 - Permit SemVer pre-release publication.
823 ## [2.3.10-0] - 2023-03-18
827 - Fix package.json `exports` syntax for ESM and CommonJS.
829 ## [2.3.9] - 2023-03-18
833 - Introduce ESM module support along with CommonJS one.
837 - Fix brown paper bag bug referencing the same object literal.
839 ## [2.3.8] - 2023-03-18
843 - Switch internal benchmarking code to benny.
844 - Switch to TypeScript 5.x.x.
845 - Switch rollup bundler plugins to core ones.
846 - Switch to TSDoc syntax.
847 - Enforce conventional commits.
851 - Fix random integer generator.
852 - Fix worker choice strategy pool type identification at initialization.
854 ## [2.3.7] - 2022-10-23
858 - Switch to open collective FOSS project funding platform.
859 - Switch to ts-standard linter configuration on TypeScript code.
863 - Fixed missing async on pool execute method.
864 - Fixed typing in TypeScript example.
865 - Fixed types in unit tests.
867 ## [2.3.6] - 2022-10-22
871 - Cleanup pool attributes and methods.
872 - Refine error types thrown.
876 - Fix continuous integration build on windows.
877 - Fix code coverage reporting by using c8 instead of nyc.
879 ## [2.3.5] - 2022-10-21
883 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
884 - Optimize tasks usage lookup implementation.
888 - Fix missed pool event emitter type export.
889 - Fix typedoc documentation generation.
891 ## [2.3.4] - 2022-10-17
895 - Fully automate release process with release-it.
899 - Optimize fair share task scheduling algorithm implementation.
900 - Update benchmark versus external pools results with latest version.
902 ## [2.3.3] - 2022-10-15
906 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
908 ## [2.3.2] - 2022-10-14
912 - Optimize fair share worker selection strategy implementation.
916 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
918 ## [2.3.1] - 2022-10-13
922 - Pool worker choice strategies:
923 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
924 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
926 ## [2.2.2] - 2022-10-09
930 - Fixed `README.md` file.
932 ## [2.2.1] - 2022-10-08
936 - Dynamic worker choice strategy change at runtime.
938 ## [2.2.0] - 2022-01-05
942 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
944 ## [2.1.0] - 2021-08-29
948 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
952 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
953 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
954 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
955 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
957 ## [2.0.2] - 2021-05-12
961 - Fix `busy` event emission on fixed pool type
963 ## [2.0.1] - 2021-03-16
967 - Check if pool options are properly set.
968 - `busy` event is emitted on all pool types.
970 ## [2.0.0] - 2021-03-01
974 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
978 - `FullPool` event is now renamed to `busy`.
979 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
980 _Find more details on our JSDoc._
982 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
984 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
986 ### Pool options types declaration merge
988 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
990 #### New `export` strategy
994 const DynamicThreadPool = require('poolifier/lib/dynamic')
996 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
999 But you should always prefer just using
1002 const { DynamicThreadPool } = require('poolifier')
1005 #### New type definitions for input data and response
1007 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
1008 _This is not a limitation by poolifier but Node.js._
1010 #### Public property replacements
1012 `numWorkers` property is now `numberOfWorkers`
1014 #### Internal (protected) properties and methods renaming
1016 These properties are not intended for end users
1018 - `id` => `nextMessageId`
1020 These methods are not intended for end users
1022 - `_chooseWorker` => `chooseWorker`
1023 - `_newWorker` => `createWorker`
1024 - `_execute` => `internalExecute`
1025 - `_chooseWorker` => `chooseWorker`
1026 - `_checkAlive` => `checkAlive`
1028 - `_runAsync` => `runAsync`
1030 ## [1.1.0] - 2020-05-21
1034 - ThreadWorker support async functions as option
1035 - Various external library patches
1037 ## [1.0.0] - 2020-01-24
1041 - FixedThreadPool implementation
1042 - DynamicThreadPool implementation
1043 - WorkerThread implementation to improve developer experience