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 ## [2.6.40] - 2023-09-01
14 - Do not pre-choose in WRR worker choice strategy to avoid bias.
15 - Avoid array out of bound in worker choice strategies after worker node removal.
17 ## [2.6.39] - 2023-08-30
21 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized .
23 ## [2.6.38] - 2023-08-30
27 - Bundle typescript types declaration into one file.
31 - Improve interleaved weighted round robin worker choice strategy implementation.
33 ## [2.6.37] - 2023-08-28
37 - Ensure unused worker usage statistics are deleted at runtime.
41 - Rename worker choice strategy options `choiceRetries` to `retries`.
42 - Avoid unnecessary branching in worker choice strategies.
44 ## [2.6.36] - 2023-08-27
48 - Fix pool `execute()` arguments check.
52 - Make continuous tasks stealing algorithm less aggressive.
53 - Fine tune tasks stealing algorithm under back pressure.
55 ## [2.6.35] - 2023-08-25
59 - Don't account worker usage statistics for tasks that have failed.
60 - Fix pool information runtime and wait time median computation.
64 - Update simple moving average implementation to use a circular buffer.
65 - Update simple moving median implementation to use a circular buffer.
66 - Account for stolen tasks in worker usage statistics and pool information.
70 - Continuous tasks stealing algorithm.
72 ## [2.6.34] - 2023-08-24
76 - Avoid cascading tasks stealing under back pressure.
80 - Add fastpath to queued tasks rescheduling.
82 ## [2.6.33] - 2023-08-24
86 - Fix queued tasks rescheduling.
90 - Rename tasks queue options `queueMaxSize` to `size`.
94 - Task stealing scheduling algorithm if tasks queueing is enabled.
96 ## [2.6.32] - 2023-08-23
100 - Ensure no task can be executed when the pool is destroyed.
104 - Add `queueMaxSize` option to tasks queue options.
105 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
106 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
108 ## [2.6.31] - 2023-08-20
112 - Fix worker choice strategy retries mechanism in some edge cases.
116 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
117 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
119 ## [2.6.30] - 2023-08-19
123 - Ensure pool event `backPressure` is emitted.
124 - Ensure pool event `full` is emitted only once.
125 - Ensure worker node cannot be instantiated without proper arguments.
127 ## [2.6.29] - 2023-08-18
131 - Fix race condition between ready and task functions worker message handling at startup.
132 - Fix duplicate task function worker usage statistics computation per task function.
133 - Update task function worker usage statistics if and only if there's at least two different task functions.
134 - Fix race condition at task function worker usage executing task computation leading to negative value.
138 - 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).
139 - Use back pressure detection in worker choice strategies.
140 - Add worker choice strategies retries mechanism if no worker is eligible.
142 ## [2.6.28] - 2023-08-16
146 - Ensure pool workers are properly initialized.
150 - HTTP server pool examples: express-cluster, express-hybrid.
154 - Remove now useless branching in worker hot code path.
156 ## [2.6.27] - 2023-08-15
160 - Add `KillHandler` type definition to exported types.
164 - Add `destroy` event to pool API.
166 ## [2.6.26] - 2023-08-15
170 - Add kill handler to worker options allowing to execute custom code when worker is killed.
171 - Add `listTaskFunctions()` method to pool API.
172 - SMTP server pool example: nodemailer.
174 ## [2.6.25] - 2023-08-13
178 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
179 - WebSocket server pool examples: ws-cluster, ws-hybrid.
181 ## [2.6.24] - 2023-08-12
185 - Add array of transferable objects to the `execute()` method arguments.
186 - WebSocket server pool examples: ws-worker_threads.
188 ## [2.6.23] - 2023-08-11
192 - 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.
196 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
197 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
199 ## [2.6.22] - 2023-08-10
203 - Add missing `types` field to package.json `exports`.
207 - Structure markdown documentation (PR #811).
209 ## [2.6.21] - 2023-08-03
213 - Improve code documentation.
214 - Code refactoring and cleanup for better maintainability and readability.
216 ## [2.6.20] - 2023-07-21
220 - Fix queued tasks redistribution on error task execution starvation.
221 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
225 - Drastically reduce lookups by worker in the worker nodes.
227 ## [2.6.19] - 2023-07-20
231 - Dedicated internal communication channel for worker_threads pools.
233 ## [2.6.18] - 2023-07-19
237 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
239 ## [2.6.17] - 2023-07-16
243 - Add `listTaskFunctions()` method to worker API.
245 ## [2.6.16] - 2023-07-12
249 - Fix pool startup detection.
250 - Fix worker task functions handling.
252 ## [2.6.15] - 2023-07-11
256 - Take into account worker node readiness in worker choice strategies.
258 ## [2.6.14] - 2023-07-10
262 - Fix task function statistics tracking.
264 ## [2.6.13] - 2023-07-10
268 - Add per task function statistics tracking.
269 - Add public methods to manipulate the worker task functions at runtime.
271 ## [2.6.12] - 2023-07-09
275 - Workaround import issue with `node:os` module in node 16.x.x.
277 ## [2.6.11] - 2023-07-09
281 - Fix pool readiness semantic.
283 ## [2.6.10] - 2023-07-08
287 - Ensure workers are not recreated on error at pool startup.
291 - Add `ready` and `strategy` fields to pool information.
292 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
293 - Add dynamic pool sizing checks.
295 ## [2.6.9] - 2023-07-07
299 - Recreate the right worker type on uncaught exception.
303 - Add minimum and maximum to internal measurement statistics.
304 - Add `runTime` and `waitTime` to pool information.
305 - Check worker inactive time only on dynamic worker.
307 ## [2.6.8] - 2023-07-03
311 - Brown paper bag release to fix version handling in pool information.
313 ## [2.6.7] - 2023-07-03
317 - Ensure worker queued tasks at error are reassigned to other pool workers.
321 - Add pool `utilization` ratio to pool information.
322 - Add `version` to pool information.
323 - Add worker information to worker nodes.
325 ## [2.6.6] - 2023-07-01
329 - Add safe helper `availableParallelism()` to help sizing the pool.
333 - Ensure message handler is only registered in worker.
335 ## [2.6.5] - 2023-06-27
339 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
343 - Artificial version bump to 2.6.5 to workaround publication issue.
344 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
345 - Ensure pool event is emitted before task error promise rejection.
346 - Fix queued tasks count computation.
350 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
352 ## [2.6.4] - 2023-06-27
356 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
360 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
361 - Ensure pool event is emitted before task error promise rejection.
362 - Fix queued tasks count computation.
366 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
368 ## [2.6.3] - 2023-06-19
372 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
373 - Update strategies internals after statistics computation.
377 - Optimize O(1) queue implementation.
379 ## [2.6.2] - 2023-06-12
383 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
385 ## [2.6.1] - 2023-06-10
389 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
393 - Fix average statistics computation: ensure failed tasks are not accounted.
395 ## [2.6.0] - 2023-06-09
399 - Add `LEAST_ELU` worker choice strategy (experimental).
400 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
404 - Refactor pool worker node usage internals.
405 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
406 - Breaking change: pool information `info` property object fields have been renamed.
410 - Fix wait time accounting.
411 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
412 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
414 ## [2.5.4] - 2023-06-07
418 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
422 - Compute statistics at the worker level only if needed.
423 - Add `worker_threads` options to thread pool options.
427 - Make the `LEAST_BUSY` strategy only relies on task runtime.
429 ## [2.5.3] - 2023-06-04
433 - Refine pool information content.
434 - Limit pool internals public exposure.
436 ## [2.5.2] - 2023-06-02
440 - Add `taskError` pool event for task execution error.
441 - Add pool information `info` property to pool.
442 - Emit pool information on `busy` and `full` pool events.
444 ## [2.5.1] - 2023-06-01
448 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
449 - Add `error` pool event for uncaught worker error.
451 ## [2.5.0] - 2023-05-31
455 - Switch pool event emitter to `EventEmitterAsyncResource`.
456 - Add tasks wait time accounting in per worker tasks usage.
457 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
461 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
463 ## [2.4.14] - 2023-05-09
467 - Ensure no undefined task runtime can land in the tasks history.
468 - Fix median computation implementation once again.
472 - Unit tests for median and queue implementations.
474 ## [2.4.13] - 2023-05-08
478 - Fix worker choice strategy options validation.
479 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
481 ## [2.4.12] - 2023-05-06
485 - Support multiple task functions per worker.
486 - Add custom worker weights support to worker choice strategies options.
490 - Use O(1) queue implementation for tasks queueing.
494 - Fix median computation implementation.
495 - Fix fair share worker choice strategy internals update.
497 ## [2.4.11] - 2023-04-23
501 - Optimize free worker finding in worker choice strategies.
503 ## [2.4.10] - 2023-04-15
507 - Fix typescript type definition for task function: ensure the input data is optional.
508 - Fix typescript type definition for pool execute(): ensure the input data is optional.
510 ## [2.4.9] - 2023-04-15
514 - Add tasks queue enablement runtime setter to pool.
515 - Add tasks queue options runtime setter to pool.
516 - Add worker choice strategy options runtime setter to pool.
520 - Remove the tasks queuing experimental status.
524 - Fix task function type definition and validation.
525 - Fix worker choice strategy options handling.
527 ## [2.4.8] - 2023-04-12
531 - Fix message between main worker and worker type definition for tasks.
532 - Fix code documentation.
534 ## [2.4.7] - 2023-04-11
538 - Add worker tasks queue options to pool options.
542 - Fix missing documentation.
544 ## [2.4.6] - 2023-04-10
548 - Ensure one task at a time is executed per worker with tasks queueing enabled.
549 - Properly count worker executing tasks with tasks queueing enabled.
551 ## [2.4.5] - 2023-04-09
555 - Use monotonic high resolution timer for worker tasks runtime.
556 - Add worker tasks median runtime to statistics.
557 - Add worker tasks queue (experimental).
559 ## [2.4.4] - 2023-04-07
563 - Add `PoolEvents` enumeration and `PoolEvent` type.
567 - Destroy worker only on alive check.
569 ## [2.4.3] - 2023-04-07
573 - Fix typedoc generation with inheritance.
575 ## [2.4.2] - 2023-04-06
579 - Add `full` event to dynamic pool.
580 - Keep worker choice strategy in memory for conditional reuse.
584 - Fix possible negative worker key at worker removal in worker choice strategies.
586 ## [2.4.1] - 2023-04-05
590 - Optimize worker choice strategy for dynamic pool.
594 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
596 ## [2.4.0] - 2023-04-04
600 - Add `LESS_BUSY` worker choice strategy.
604 - Optimize worker storage in pool.
605 - Optimize worker alive status check.
606 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
607 - Optimize `LESS_USED` worker choice strategy.
608 - Update benchmarks versus external threads pools.
609 - Optimize tasks usage statistics requirements for worker choice strategy.
613 - Ensure trimmable characters are checked at pool initialization.
614 - Fix message id integer overflow.
615 - Fix pool worker removal in worker choice strategy internals.
616 - Fix package publication with pnpm.
618 ## [2.4.0-3] - 2023-04-04
622 - Add `LESS_BUSY` worker choice strategy.
626 - Optimize worker storage in pool.
627 - Optimize worker alive status check.
628 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
629 - Optimize `LESS_USED` worker choice strategy.
630 - Update benchmarks versus external threads pools.
634 - Ensure trimmable characters are checked at pool initialization.
635 - Fix message id integer overflow.
636 - Fix pool worker removal in worker choice strategy internals.
637 - Fix package publication with pnpm.
639 ## [2.4.0-2] - 2023-04-03
643 - Add `LESS_BUSY` worker choice strategy.
647 - Optimize worker storage in pool.
648 - Optimize worker alive status check.
649 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
650 - Optimize `LESS_USED` worker choice strategy.
654 - Ensure trimmable characters are checked at pool initialization.
655 - Fix message id integer overflow.
656 - Fix pool worker removal in worker choice strategy internals.
657 - Fix package publication with pnpm.
659 ## [2.4.0-1] - 2023-04-03
663 - Add `LESS_BUSY` worker choice strategy.
667 - Optimize worker storage in pool.
668 - Optimize worker alive status check.
669 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
670 - Optimize `LESS_USED` worker choice strategy.
674 - Ensure trimmable characters are checked at pool initialization.
675 - Fix message id integer overflow.
676 - Fix pool worker removal in worker choice strategy internals.
678 ## [2.4.0-0] - 2023-04-03
682 - Add `LESS_BUSY` worker choice strategy.
686 - Optimize worker storage in pool.
687 - Optimize worker alive status check.
688 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
689 - Optimize `LESS_USED` 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.
697 ## [2.3.10] - 2023-03-18
701 - Fix package.json `exports` syntax for ESM and CommonJS.
705 - Permit SemVer pre-release publication.
707 ## [2.3.10-2] - 2023-03-18
711 - Fix package.json `exports` syntax for ESM and CommonJS.
713 ## [2.3.10-1] - 2023-03-18
717 - Permit SemVer pre-release publication.
719 ## [2.3.10-0] - 2023-03-18
723 - Fix package.json `exports` syntax for ESM and CommonJS.
725 ## [2.3.9] - 2023-03-18
729 - Introduce ESM module support along with CommonJS one.
733 - Fix brown paper bag bug referencing the same object literal.
735 ## [2.3.8] - 2023-03-18
739 - Switch internal benchmarking code to benny.
740 - Switch to TypeScript 5.x.x.
741 - Switch rollup bundler plugins to core ones.
742 - Switch to TSDoc syntax.
743 - Enforce conventional commits.
747 - Fix random integer generator.
748 - Fix worker choice strategy pool type identification at initialization.
750 ## [2.3.7] - 2022-10-23
754 - Switch to open collective FOSS project funding platform.
755 - Switch to ts-standard linter configuration on TypeScript code.
759 - Fixed missing async on pool execute method.
760 - Fixed typing in TypeScript example.
761 - Fixed types in unit tests.
763 ## [2.3.6] - 2022-10-22
767 - Cleanup pool attributes and methods.
768 - Refine error types thrown.
772 - Fix continuous integration build on windows.
773 - Fix code coverage reporting by using c8 instead of nyc.
775 ## [2.3.5] - 2022-10-21
779 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
780 - Optimize tasks usage lookup implementation.
784 - Fix missed pool event emitter type export.
785 - Fix typedoc documentation generation.
787 ## [2.3.4] - 2022-10-17
791 - Fully automate release process with release-it.
795 - Optimize fair share task scheduling algorithm implementation.
796 - Update benchmarks versus external pools results with latest version.
798 ## [2.3.3] - 2022-10-15
802 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
804 ## [2.3.2] - 2022-10-14
808 - Optimize fair share worker selection strategy implementation.
812 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
814 ## [2.3.1] - 2022-10-13
818 - Pool worker choice strategies:
819 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
820 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
822 ## [2.2.2] - 2022-10-09
826 - Fixed `README.md` file.
828 ## [2.2.1] - 2022-10-08
832 - Dynamic worker choice strategy change at runtime.
834 ## [2.2.0] - 2022-01-05
838 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
840 ## [2.1.0] - 2021-08-29
844 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
848 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
849 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
850 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
851 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
853 ## [2.0.2] - 2021-05-12
857 - Fix `busy` event emission on fixed pool type
859 ## [2.0.1] - 2021-03-16
863 - Check if pool options are properly set.
864 - `busy` event is emitted on all pool types.
866 ## [2.0.0] - 2021-03-01
870 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
874 - `FullPool` event is now renamed to `busy`.
875 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
876 _Find more details on our JSDoc._
878 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
880 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
882 ### Pool options types declaration merge
884 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
886 #### New `export` strategy
890 const DynamicThreadPool = require('poolifier/lib/dynamic')
892 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
895 But you should always prefer just using
898 const { DynamicThreadPool } = require('poolifier')
901 #### New type definitions for input data and response
903 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
904 _This is not a limitation by poolifier but Node.js._
906 #### Public property replacements
908 `numWorkers` property is now `numberOfWorkers`
910 #### Internal (protected) properties and methods renaming
912 These properties are not intended for end users
914 - `id` => `nextMessageId`
916 These methods are not intended for end users
918 - `_chooseWorker` => `chooseWorker`
919 - `_newWorker` => `createWorker`
920 - `_execute` => `internalExecute`
921 - `_chooseWorker` => `chooseWorker`
922 - `_checkAlive` => `checkAlive`
924 - `_runAsync` => `runAsync`
926 ## [1.1.0] - 2020-05-21
930 - ThreadWorker support async functions as option
931 - Various external library patches
933 ## [1.0.0] - 2020-01-24
937 - FixedThreadPool implementation
938 - DynamicThreadPool implementation
939 - WorkerThread implementation to improve developer experience