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 ## [2.6.41] - 2023-09-03
14 - Optimize worker choice strategies implementation.
16 ## [2.6.40] - 2023-09-01
20 - Do not pre-choose in WRR worker choice strategy to avoid bias.
21 - Avoid array out of bound in worker choice strategies after worker node removal.
23 ## [2.6.39] - 2023-08-30
27 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized .
29 ## [2.6.38] - 2023-08-30
33 - Bundle typescript types declaration into one file.
37 - Improve interleaved weighted round robin worker choice strategy implementation.
39 ## [2.6.37] - 2023-08-28
43 - Ensure unused worker usage statistics are deleted at runtime.
47 - Rename worker choice strategy options `choiceRetries` to `retries`.
48 - Avoid unnecessary branching in worker choice strategies.
50 ## [2.6.36] - 2023-08-27
54 - Fix pool `execute()` arguments check.
58 - Make continuous tasks stealing algorithm less aggressive.
59 - Fine tune tasks stealing algorithm under back pressure.
61 ## [2.6.35] - 2023-08-25
65 - Don't account worker usage statistics for tasks that have failed.
66 - Fix pool information runtime and wait time median computation.
70 - Update simple moving average implementation to use a circular buffer.
71 - Update simple moving median implementation to use a circular buffer.
72 - Account for stolen tasks in worker usage statistics and pool information.
76 - Continuous tasks stealing algorithm.
78 ## [2.6.34] - 2023-08-24
82 - Avoid cascading tasks stealing under back pressure.
86 - Add fastpath to queued tasks rescheduling.
88 ## [2.6.33] - 2023-08-24
92 - Fix queued tasks rescheduling.
96 - Rename tasks queue options `queueMaxSize` to `size`.
100 - Task stealing scheduling algorithm if tasks queueing is enabled.
102 ## [2.6.32] - 2023-08-23
106 - Ensure no task can be executed when the pool is destroyed.
110 - Add `queueMaxSize` option to tasks queue options.
111 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
112 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
114 ## [2.6.31] - 2023-08-20
118 - Fix worker choice strategy retries mechanism in some edge cases.
122 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
123 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
125 ## [2.6.30] - 2023-08-19
129 - Ensure pool event `backPressure` is emitted.
130 - Ensure pool event `full` is emitted only once.
131 - Ensure worker node cannot be instantiated without proper arguments.
133 ## [2.6.29] - 2023-08-18
137 - Fix race condition between ready and task functions worker message handling at startup.
138 - Fix duplicate task function worker usage statistics computation per task function.
139 - Update task function worker usage statistics if and only if there's at least two different task functions.
140 - Fix race condition at task function worker usage executing task computation leading to negative value.
144 - 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).
145 - Use back pressure detection in worker choice strategies.
146 - Add worker choice strategies retries mechanism if no worker is eligible.
148 ## [2.6.28] - 2023-08-16
152 - Ensure pool workers are properly initialized.
156 - HTTP server pool examples: express-cluster, express-hybrid.
160 - Remove now useless branching in worker hot code path.
162 ## [2.6.27] - 2023-08-15
166 - Add `KillHandler` type definition to exported types.
170 - Add `destroy` event to pool API.
172 ## [2.6.26] - 2023-08-15
176 - Add kill handler to worker options allowing to execute custom code when worker is killed.
177 - Add `listTaskFunctions()` method to pool API.
178 - SMTP server pool example: nodemailer.
180 ## [2.6.25] - 2023-08-13
184 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
185 - WebSocket server pool examples: ws-cluster, ws-hybrid.
187 ## [2.6.24] - 2023-08-12
191 - Add array of transferable objects to the `execute()` method arguments.
192 - WebSocket server pool examples: ws-worker_threads.
194 ## [2.6.23] - 2023-08-11
198 - 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.
202 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
203 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
205 ## [2.6.22] - 2023-08-10
209 - Add missing `types` field to package.json `exports`.
213 - Structure markdown documentation (PR #811).
215 ## [2.6.21] - 2023-08-03
219 - Improve code documentation.
220 - Code refactoring and cleanup for better maintainability and readability.
222 ## [2.6.20] - 2023-07-21
226 - Fix queued tasks redistribution on error task execution starvation.
227 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
231 - Drastically reduce lookups by worker in the worker nodes.
233 ## [2.6.19] - 2023-07-20
237 - Dedicated internal communication channel for worker_threads pools.
239 ## [2.6.18] - 2023-07-19
243 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
245 ## [2.6.17] - 2023-07-16
249 - Add `listTaskFunctions()` method to worker API.
251 ## [2.6.16] - 2023-07-12
255 - Fix pool startup detection.
256 - Fix worker task functions handling.
258 ## [2.6.15] - 2023-07-11
262 - Take into account worker node readiness in worker choice strategies.
264 ## [2.6.14] - 2023-07-10
268 - Fix task function statistics tracking.
270 ## [2.6.13] - 2023-07-10
274 - Add per task function statistics tracking.
275 - Add public methods to manipulate the worker task functions at runtime.
277 ## [2.6.12] - 2023-07-09
281 - Workaround import issue with `node:os` module in node 16.x.x.
283 ## [2.6.11] - 2023-07-09
287 - Fix pool readiness semantic.
289 ## [2.6.10] - 2023-07-08
293 - Ensure workers are not recreated on error at pool startup.
297 - Add `ready` and `strategy` fields to pool information.
298 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
299 - Add dynamic pool sizing checks.
301 ## [2.6.9] - 2023-07-07
305 - Recreate the right worker type on uncaught exception.
309 - Add minimum and maximum to internal measurement statistics.
310 - Add `runTime` and `waitTime` to pool information.
311 - Check worker inactive time only on dynamic worker.
313 ## [2.6.8] - 2023-07-03
317 - Brown paper bag release to fix version handling in pool information.
319 ## [2.6.7] - 2023-07-03
323 - Ensure worker queued tasks at error are reassigned to other pool workers.
327 - Add pool `utilization` ratio to pool information.
328 - Add `version` to pool information.
329 - Add worker information to worker nodes.
331 ## [2.6.6] - 2023-07-01
335 - Add safe helper `availableParallelism()` to help sizing the pool.
339 - Ensure message handler is only registered in worker.
341 ## [2.6.5] - 2023-06-27
345 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
349 - Artificial version bump to 2.6.5 to workaround publication issue.
350 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
351 - Ensure pool event is emitted before task error promise rejection.
352 - Fix queued tasks count computation.
356 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
358 ## [2.6.4] - 2023-06-27
362 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
366 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
367 - Ensure pool event is emitted before task error promise rejection.
368 - Fix queued tasks count computation.
372 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
374 ## [2.6.3] - 2023-06-19
378 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
379 - Update strategies internals after statistics computation.
383 - Optimize O(1) queue implementation.
385 ## [2.6.2] - 2023-06-12
389 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
391 ## [2.6.1] - 2023-06-10
395 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
399 - Fix average statistics computation: ensure failed tasks are not accounted.
401 ## [2.6.0] - 2023-06-09
405 - Add `LEAST_ELU` worker choice strategy (experimental).
406 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
410 - Refactor pool worker node usage internals.
411 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
412 - Breaking change: pool information `info` property object fields have been renamed.
416 - Fix wait time accounting.
417 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
418 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
420 ## [2.5.4] - 2023-06-07
424 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
428 - Compute statistics at the worker level only if needed.
429 - Add `worker_threads` options to thread pool options.
433 - Make the `LEAST_BUSY` strategy only relies on task runtime.
435 ## [2.5.3] - 2023-06-04
439 - Refine pool information content.
440 - Limit pool internals public exposure.
442 ## [2.5.2] - 2023-06-02
446 - Add `taskError` pool event for task execution error.
447 - Add pool information `info` property to pool.
448 - Emit pool information on `busy` and `full` pool events.
450 ## [2.5.1] - 2023-06-01
454 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
455 - Add `error` pool event for uncaught worker error.
457 ## [2.5.0] - 2023-05-31
461 - Switch pool event emitter to `EventEmitterAsyncResource`.
462 - Add tasks wait time accounting in per worker tasks usage.
463 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
467 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
469 ## [2.4.14] - 2023-05-09
473 - Ensure no undefined task runtime can land in the tasks history.
474 - Fix median computation implementation once again.
478 - Unit tests for median and queue implementations.
480 ## [2.4.13] - 2023-05-08
484 - Fix worker choice strategy options validation.
485 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
487 ## [2.4.12] - 2023-05-06
491 - Support multiple task functions per worker.
492 - Add custom worker weights support to worker choice strategies options.
496 - Use O(1) queue implementation for tasks queueing.
500 - Fix median computation implementation.
501 - Fix fair share worker choice strategy internals update.
503 ## [2.4.11] - 2023-04-23
507 - Optimize free worker finding in worker choice strategies.
509 ## [2.4.10] - 2023-04-15
513 - Fix typescript type definition for task function: ensure the input data is optional.
514 - Fix typescript type definition for pool execute(): ensure the input data is optional.
516 ## [2.4.9] - 2023-04-15
520 - Add tasks queue enablement runtime setter to pool.
521 - Add tasks queue options runtime setter to pool.
522 - Add worker choice strategy options runtime setter to pool.
526 - Remove the tasks queuing experimental status.
530 - Fix task function type definition and validation.
531 - Fix worker choice strategy options handling.
533 ## [2.4.8] - 2023-04-12
537 - Fix message between main worker and worker type definition for tasks.
538 - Fix code documentation.
540 ## [2.4.7] - 2023-04-11
544 - Add worker tasks queue options to pool options.
548 - Fix missing documentation.
550 ## [2.4.6] - 2023-04-10
554 - Ensure one task at a time is executed per worker with tasks queueing enabled.
555 - Properly count worker executing tasks with tasks queueing enabled.
557 ## [2.4.5] - 2023-04-09
561 - Use monotonic high resolution timer for worker tasks runtime.
562 - Add worker tasks median runtime to statistics.
563 - Add worker tasks queue (experimental).
565 ## [2.4.4] - 2023-04-07
569 - Add `PoolEvents` enumeration and `PoolEvent` type.
573 - Destroy worker only on alive check.
575 ## [2.4.3] - 2023-04-07
579 - Fix typedoc generation with inheritance.
581 ## [2.4.2] - 2023-04-06
585 - Add `full` event to dynamic pool.
586 - Keep worker choice strategy in memory for conditional reuse.
590 - Fix possible negative worker key at worker removal in worker choice strategies.
592 ## [2.4.1] - 2023-04-05
596 - Optimize worker choice strategy for dynamic pool.
600 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
602 ## [2.4.0] - 2023-04-04
606 - Add `LESS_BUSY` worker choice strategy.
610 - Optimize worker storage in pool.
611 - Optimize worker alive status check.
612 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
613 - Optimize `LESS_USED` worker choice strategy.
614 - Update benchmarks versus external threads pools.
615 - Optimize tasks usage statistics requirements for worker choice strategy.
619 - Ensure trimmable characters are checked at pool initialization.
620 - Fix message id integer overflow.
621 - Fix pool worker removal in worker choice strategy internals.
622 - Fix package publication with pnpm.
624 ## [2.4.0-3] - 2023-04-04
628 - Add `LESS_BUSY` worker choice strategy.
632 - Optimize worker storage in pool.
633 - Optimize worker alive status check.
634 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
635 - Optimize `LESS_USED` worker choice strategy.
636 - Update benchmarks versus external threads pools.
640 - Ensure trimmable characters are checked at pool initialization.
641 - Fix message id integer overflow.
642 - Fix pool worker removal in worker choice strategy internals.
643 - Fix package publication with pnpm.
645 ## [2.4.0-2] - 2023-04-03
649 - Add `LESS_BUSY` worker choice strategy.
653 - Optimize worker storage in pool.
654 - Optimize worker alive status check.
655 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
656 - Optimize `LESS_USED` worker choice strategy.
660 - Ensure trimmable characters are checked at pool initialization.
661 - Fix message id integer overflow.
662 - Fix pool worker removal in worker choice strategy internals.
663 - Fix package publication with pnpm.
665 ## [2.4.0-1] - 2023-04-03
669 - Add `LESS_BUSY` worker choice strategy.
673 - Optimize worker storage in pool.
674 - Optimize worker alive status check.
675 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
676 - Optimize `LESS_USED` worker choice strategy.
680 - Ensure trimmable characters are checked at pool initialization.
681 - Fix message id integer overflow.
682 - Fix pool worker removal in worker choice strategy internals.
684 ## [2.4.0-0] - 2023-04-03
688 - Add `LESS_BUSY` worker choice strategy.
692 - Optimize worker storage in pool.
693 - Optimize worker alive status check.
694 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
695 - Optimize `LESS_USED` 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.
703 ## [2.3.10] - 2023-03-18
707 - Fix package.json `exports` syntax for ESM and CommonJS.
711 - Permit SemVer pre-release publication.
713 ## [2.3.10-2] - 2023-03-18
717 - Fix package.json `exports` syntax for ESM and CommonJS.
719 ## [2.3.10-1] - 2023-03-18
723 - Permit SemVer pre-release publication.
725 ## [2.3.10-0] - 2023-03-18
729 - Fix package.json `exports` syntax for ESM and CommonJS.
731 ## [2.3.9] - 2023-03-18
735 - Introduce ESM module support along with CommonJS one.
739 - Fix brown paper bag bug referencing the same object literal.
741 ## [2.3.8] - 2023-03-18
745 - Switch internal benchmarking code to benny.
746 - Switch to TypeScript 5.x.x.
747 - Switch rollup bundler plugins to core ones.
748 - Switch to TSDoc syntax.
749 - Enforce conventional commits.
753 - Fix random integer generator.
754 - Fix worker choice strategy pool type identification at initialization.
756 ## [2.3.7] - 2022-10-23
760 - Switch to open collective FOSS project funding platform.
761 - Switch to ts-standard linter configuration on TypeScript code.
765 - Fixed missing async on pool execute method.
766 - Fixed typing in TypeScript example.
767 - Fixed types in unit tests.
769 ## [2.3.6] - 2022-10-22
773 - Cleanup pool attributes and methods.
774 - Refine error types thrown.
778 - Fix continuous integration build on windows.
779 - Fix code coverage reporting by using c8 instead of nyc.
781 ## [2.3.5] - 2022-10-21
785 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
786 - Optimize tasks usage lookup implementation.
790 - Fix missed pool event emitter type export.
791 - Fix typedoc documentation generation.
793 ## [2.3.4] - 2022-10-17
797 - Fully automate release process with release-it.
801 - Optimize fair share task scheduling algorithm implementation.
802 - Update benchmarks versus external pools results with latest version.
804 ## [2.3.3] - 2022-10-15
808 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
810 ## [2.3.2] - 2022-10-14
814 - Optimize fair share worker selection strategy implementation.
818 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
820 ## [2.3.1] - 2022-10-13
824 - Pool worker choice strategies:
825 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
826 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
828 ## [2.2.2] - 2022-10-09
832 - Fixed `README.md` file.
834 ## [2.2.1] - 2022-10-08
838 - Dynamic worker choice strategy change at runtime.
840 ## [2.2.0] - 2022-01-05
844 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
846 ## [2.1.0] - 2021-08-29
850 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
854 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
855 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
856 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
857 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
859 ## [2.0.2] - 2021-05-12
863 - Fix `busy` event emission on fixed pool type
865 ## [2.0.1] - 2021-03-16
869 - Check if pool options are properly set.
870 - `busy` event is emitted on all pool types.
872 ## [2.0.0] - 2021-03-01
876 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
880 - `FullPool` event is now renamed to `busy`.
881 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
882 _Find more details on our JSDoc._
884 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
886 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
888 ### Pool options types declaration merge
890 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
892 #### New `export` strategy
896 const DynamicThreadPool = require('poolifier/lib/dynamic')
898 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
901 But you should always prefer just using
904 const { DynamicThreadPool } = require('poolifier')
907 #### New type definitions for input data and response
909 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
910 _This is not a limitation by poolifier but Node.js._
912 #### Public property replacements
914 `numWorkers` property is now `numberOfWorkers`
916 #### Internal (protected) properties and methods renaming
918 These properties are not intended for end users
920 - `id` => `nextMessageId`
922 These methods are not intended for end users
924 - `_chooseWorker` => `chooseWorker`
925 - `_newWorker` => `createWorker`
926 - `_execute` => `internalExecute`
927 - `_chooseWorker` => `chooseWorker`
928 - `_checkAlive` => `checkAlive`
930 - `_runAsync` => `runAsync`
932 ## [1.1.0] - 2020-05-21
936 - ThreadWorker support async functions as option
937 - Various external library patches
939 ## [1.0.0] - 2020-01-24
943 - FixedThreadPool implementation
944 - DynamicThreadPool implementation
945 - WorkerThread implementation to improve developer experience