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).
12 - Do not pre-choose in WRR worker choice strategy to avoid bias.
13 - Avoid array out of bound in worker choice strategies after worker node removal.
15 ## [2.6.39] - 2023-08-30
19 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized .
21 ## [2.6.38] - 2023-08-30
25 - Bundle typescript types declaration into one file.
29 - Improve interleaved weighted round robin worker choice strategy implementation.
31 ## [2.6.37] - 2023-08-28
35 - Ensure unused worker usage statistics are deleted at runtime.
39 - Rename worker choice strategy options `choiceRetries` to `retries`.
40 - Avoid unnecessary branching in worker choice strategies.
42 ## [2.6.36] - 2023-08-27
46 - Fix pool `execute()` arguments check.
50 - Make continuous tasks stealing algorithm less aggressive.
51 - Fine tune tasks stealing algorithm under back pressure.
53 ## [2.6.35] - 2023-08-25
57 - Don't account worker usage statistics for tasks that have failed.
58 - Fix pool information runtime and wait time median computation.
62 - Update simple moving average implementation to use a circular buffer.
63 - Update simple moving median implementation to use a circular buffer.
64 - Account for stolen tasks in worker usage statistics and pool information.
68 - Continuous tasks stealing algorithm.
70 ## [2.6.34] - 2023-08-24
74 - Avoid cascading tasks stealing under back pressure.
78 - Add fastpath to queued tasks rescheduling.
80 ## [2.6.33] - 2023-08-24
84 - Fix queued tasks rescheduling.
88 - Rename tasks queue options `queueMaxSize` to `size`.
92 - Task stealing scheduling algorithm if tasks queueing is enabled.
94 ## [2.6.32] - 2023-08-23
98 - Ensure no task can be executed when the pool is destroyed.
102 - Add `queueMaxSize` option to tasks queue options.
103 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
104 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
106 ## [2.6.31] - 2023-08-20
110 - Fix worker choice strategy retries mechanism in some edge cases.
114 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
115 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
117 ## [2.6.30] - 2023-08-19
121 - Ensure pool event `backPressure` is emitted.
122 - Ensure pool event `full` is emitted only once.
123 - Ensure worker node cannot be instantiated without proper arguments.
125 ## [2.6.29] - 2023-08-18
129 - Fix race condition between ready and task functions worker message handling at startup.
130 - Fix duplicate task function worker usage statistics computation per task function.
131 - Update task function worker usage statistics if and only if there's at least two different task functions.
132 - Fix race condition at task function worker usage executing task computation leading to negative value.
136 - 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).
137 - Use back pressure detection in worker choice strategies.
138 - Add worker choice strategies retries mechanism if no worker is eligible.
140 ## [2.6.28] - 2023-08-16
144 - Ensure pool workers are properly initialized.
148 - HTTP server pool examples: express-cluster, express-hybrid.
152 - Remove now useless branching in worker hot code path.
154 ## [2.6.27] - 2023-08-15
158 - Add `KillHandler` type definition to exported types.
162 - Add `destroy` event to pool API.
164 ## [2.6.26] - 2023-08-15
168 - Add kill handler to worker options allowing to execute custom code when worker is killed.
169 - Add `listTaskFunctions()` method to pool API.
170 - SMTP server pool example: nodemailer.
172 ## [2.6.25] - 2023-08-13
176 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
177 - WebSocket server pool examples: ws-cluster, ws-hybrid.
179 ## [2.6.24] - 2023-08-12
183 - Add array of transferable objects to the `execute()` method arguments.
184 - WebSocket server pool examples: ws-worker_threads.
186 ## [2.6.23] - 2023-08-11
190 - 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.
194 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
195 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
197 ## [2.6.22] - 2023-08-10
201 - Add missing `types` field to package.json `exports`.
205 - Structure markdown documentation (PR #811).
207 ## [2.6.21] - 2023-08-03
211 - Improve code documentation.
212 - Code refactoring and cleanup for better maintainability and readability.
214 ## [2.6.20] - 2023-07-21
218 - Fix queued tasks redistribution on error task execution starvation.
219 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
223 - Drastically reduce lookups by worker in the worker nodes.
225 ## [2.6.19] - 2023-07-20
229 - Dedicated internal communication channel for worker_threads pools.
231 ## [2.6.18] - 2023-07-19
235 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
237 ## [2.6.17] - 2023-07-16
241 - Add `listTaskFunctions()` method to worker API.
243 ## [2.6.16] - 2023-07-12
247 - Fix pool startup detection.
248 - Fix worker task functions handling.
250 ## [2.6.15] - 2023-07-11
254 - Take into account worker node readiness in worker choice strategies.
256 ## [2.6.14] - 2023-07-10
260 - Fix task function statistics tracking.
262 ## [2.6.13] - 2023-07-10
266 - Add per task function statistics tracking.
267 - Add public methods to manipulate the worker task functions at runtime.
269 ## [2.6.12] - 2023-07-09
273 - Workaround import issue with `node:os` module in node 16.x.x.
275 ## [2.6.11] - 2023-07-09
279 - Fix pool readiness semantic.
281 ## [2.6.10] - 2023-07-08
285 - Ensure workers are not recreated on error at pool startup.
289 - Add `ready` and `strategy` fields to pool information.
290 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
291 - Add dynamic pool sizing checks.
293 ## [2.6.9] - 2023-07-07
297 - Recreate the right worker type on uncaught exception.
301 - Add minimum and maximum to internal measurement statistics.
302 - Add `runTime` and `waitTime` to pool information.
303 - Check worker inactive time only on dynamic worker.
305 ## [2.6.8] - 2023-07-03
309 - Brown paper bag release to fix version handling in pool information.
311 ## [2.6.7] - 2023-07-03
315 - Ensure worker queued tasks at error are reassigned to other pool workers.
319 - Add pool `utilization` ratio to pool information.
320 - Add `version` to pool information.
321 - Add worker information to worker nodes.
323 ## [2.6.6] - 2023-07-01
327 - Add safe helper `availableParallelism()` to help sizing the pool.
331 - Ensure message handler is only registered in worker.
333 ## [2.6.5] - 2023-06-27
337 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
341 - Artificial version bump to 2.6.5 to workaround publication issue.
342 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
343 - Ensure pool event is emitted before task error promise rejection.
344 - Fix queued tasks count computation.
348 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
350 ## [2.6.4] - 2023-06-27
354 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
358 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
359 - Ensure pool event is emitted before task error promise rejection.
360 - Fix queued tasks count computation.
364 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
366 ## [2.6.3] - 2023-06-19
370 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
371 - Update strategies internals after statistics computation.
375 - Optimize O(1) queue implementation.
377 ## [2.6.2] - 2023-06-12
381 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
383 ## [2.6.1] - 2023-06-10
387 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
391 - Fix average statistics computation: ensure failed tasks are not accounted.
393 ## [2.6.0] - 2023-06-09
397 - Add `LEAST_ELU` worker choice strategy (experimental).
398 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
402 - Refactor pool worker node usage internals.
403 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
404 - Breaking change: pool information `info` property object fields have been renamed.
408 - Fix wait time accounting.
409 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
410 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
412 ## [2.5.4] - 2023-06-07
416 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
420 - Compute statistics at the worker level only if needed.
421 - Add `worker_threads` options to thread pool options.
425 - Make the `LEAST_BUSY` strategy only relies on task runtime.
427 ## [2.5.3] - 2023-06-04
431 - Refine pool information content.
432 - Limit pool internals public exposure.
434 ## [2.5.2] - 2023-06-02
438 - Add `taskError` pool event for task execution error.
439 - Add pool information `info` property to pool.
440 - Emit pool information on `busy` and `full` pool events.
442 ## [2.5.1] - 2023-06-01
446 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
447 - Add `error` pool event for uncaught worker error.
449 ## [2.5.0] - 2023-05-31
453 - Switch pool event emitter to `EventEmitterAsyncResource`.
454 - Add tasks wait time accounting in per worker tasks usage.
455 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
459 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
461 ## [2.4.14] - 2023-05-09
465 - Ensure no undefined task runtime can land in the tasks history.
466 - Fix median computation implementation once again.
470 - Unit tests for median and queue implementations.
472 ## [2.4.13] - 2023-05-08
476 - Fix worker choice strategy options validation.
477 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
479 ## [2.4.12] - 2023-05-06
483 - Support multiple task functions per worker.
484 - Add custom worker weights support to worker choice strategies options.
488 - Use O(1) queue implementation for tasks queueing.
492 - Fix median computation implementation.
493 - Fix fair share worker choice strategy internals update.
495 ## [2.4.11] - 2023-04-23
499 - Optimize free worker finding in worker choice strategies.
501 ## [2.4.10] - 2023-04-15
505 - Fix typescript type definition for task function: ensure the input data is optional.
506 - Fix typescript type definition for pool execute(): ensure the input data is optional.
508 ## [2.4.9] - 2023-04-15
512 - Add tasks queue enablement runtime setter to pool.
513 - Add tasks queue options runtime setter to pool.
514 - Add worker choice strategy options runtime setter to pool.
518 - Remove the tasks queuing experimental status.
522 - Fix task function type definition and validation.
523 - Fix worker choice strategy options handling.
525 ## [2.4.8] - 2023-04-12
529 - Fix message between main worker and worker type definition for tasks.
530 - Fix code documentation.
532 ## [2.4.7] - 2023-04-11
536 - Add worker tasks queue options to pool options.
540 - Fix missing documentation.
542 ## [2.4.6] - 2023-04-10
546 - Ensure one task at a time is executed per worker with tasks queueing enabled.
547 - Properly count worker executing tasks with tasks queueing enabled.
549 ## [2.4.5] - 2023-04-09
553 - Use monotonic high resolution timer for worker tasks runtime.
554 - Add worker tasks median runtime to statistics.
555 - Add worker tasks queue (experimental).
557 ## [2.4.4] - 2023-04-07
561 - Add `PoolEvents` enumeration and `PoolEvent` type.
565 - Destroy worker only on alive check.
567 ## [2.4.3] - 2023-04-07
571 - Fix typedoc generation with inheritance.
573 ## [2.4.2] - 2023-04-06
577 - Add `full` event to dynamic pool.
578 - Keep worker choice strategy in memory for conditional reuse.
582 - Fix possible negative worker key at worker removal in worker choice strategies.
584 ## [2.4.1] - 2023-04-05
588 - Optimize worker choice strategy for dynamic pool.
592 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
594 ## [2.4.0] - 2023-04-04
598 - Add `LESS_BUSY` worker choice strategy.
602 - Optimize worker storage in pool.
603 - Optimize worker alive status check.
604 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
605 - Optimize `LESS_USED` worker choice strategy.
606 - Update benchmarks versus external threads pools.
607 - Optimize tasks usage statistics requirements for worker choice strategy.
611 - Ensure trimmable characters are checked at pool initialization.
612 - Fix message id integer overflow.
613 - Fix pool worker removal in worker choice strategy internals.
614 - Fix package publication with pnpm.
616 ## [2.4.0-3] - 2023-04-04
620 - Add `LESS_BUSY` worker choice strategy.
624 - Optimize worker storage in pool.
625 - Optimize worker alive status check.
626 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
627 - Optimize `LESS_USED` worker choice strategy.
628 - Update benchmarks versus external threads pools.
632 - Ensure trimmable characters are checked at pool initialization.
633 - Fix message id integer overflow.
634 - Fix pool worker removal in worker choice strategy internals.
635 - Fix package publication with pnpm.
637 ## [2.4.0-2] - 2023-04-03
641 - Add `LESS_BUSY` worker choice strategy.
645 - Optimize worker storage in pool.
646 - Optimize worker alive status check.
647 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
648 - Optimize `LESS_USED` worker choice strategy.
652 - Ensure trimmable characters are checked at pool initialization.
653 - Fix message id integer overflow.
654 - Fix pool worker removal in worker choice strategy internals.
655 - Fix package publication with pnpm.
657 ## [2.4.0-1] - 2023-04-03
661 - Add `LESS_BUSY` worker choice strategy.
665 - Optimize worker storage in pool.
666 - Optimize worker alive status check.
667 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
668 - Optimize `LESS_USED` worker choice strategy.
672 - Ensure trimmable characters are checked at pool initialization.
673 - Fix message id integer overflow.
674 - Fix pool worker removal in worker choice strategy internals.
676 ## [2.4.0-0] - 2023-04-03
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.
691 - Ensure trimmable characters are checked at pool initialization.
692 - Fix message id integer overflow.
693 - Fix pool worker removal in worker choice strategy internals.
695 ## [2.3.10] - 2023-03-18
699 - Fix package.json `exports` syntax for ESM and CommonJS.
703 - Permit SemVer pre-release publication.
705 ## [2.3.10-2] - 2023-03-18
709 - Fix package.json `exports` syntax for ESM and CommonJS.
711 ## [2.3.10-1] - 2023-03-18
715 - Permit SemVer pre-release publication.
717 ## [2.3.10-0] - 2023-03-18
721 - Fix package.json `exports` syntax for ESM and CommonJS.
723 ## [2.3.9] - 2023-03-18
727 - Introduce ESM module support along with CommonJS one.
731 - Fix brown paper bag bug referencing the same object literal.
733 ## [2.3.8] - 2023-03-18
737 - Switch internal benchmarking code to benny.
738 - Switch to TypeScript 5.x.x.
739 - Switch rollup bundler plugins to core ones.
740 - Switch to TSDoc syntax.
741 - Enforce conventional commits.
745 - Fix random integer generator.
746 - Fix worker choice strategy pool type identification at initialization.
748 ## [2.3.7] - 2022-10-23
752 - Switch to open collective FOSS project funding platform.
753 - Switch to ts-standard linter configuration on TypeScript code.
757 - Fixed missing async on pool execute method.
758 - Fixed typing in TypeScript example.
759 - Fixed types in unit tests.
761 ## [2.3.6] - 2022-10-22
765 - Cleanup pool attributes and methods.
766 - Refine error types thrown.
770 - Fix continuous integration build on windows.
771 - Fix code coverage reporting by using c8 instead of nyc.
773 ## [2.3.5] - 2022-10-21
777 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
778 - Optimize tasks usage lookup implementation.
782 - Fix missed pool event emitter type export.
783 - Fix typedoc documentation generation.
785 ## [2.3.4] - 2022-10-17
789 - Fully automate release process with release-it.
793 - Optimize fair share task scheduling algorithm implementation.
794 - Update benchmarks versus external pools results with latest version.
796 ## [2.3.3] - 2022-10-15
800 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
802 ## [2.3.2] - 2022-10-14
806 - Optimize fair share worker selection strategy implementation.
810 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
812 ## [2.3.1] - 2022-10-13
816 - Pool worker choice strategies:
817 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
818 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
820 ## [2.2.2] - 2022-10-09
824 - Fixed `README.md` file.
826 ## [2.2.1] - 2022-10-08
830 - Dynamic worker choice strategy change at runtime.
832 ## [2.2.0] - 2022-01-05
836 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
838 ## [2.1.0] - 2021-08-29
842 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
846 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
847 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
848 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
849 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
851 ## [2.0.2] - 2021-05-12
855 - Fix `busy` event emission on fixed pool type
857 ## [2.0.1] - 2021-03-16
861 - Check if pool options are properly set.
862 - `busy` event is emitted on all pool types.
864 ## [2.0.0] - 2021-03-01
868 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
872 - `FullPool` event is now renamed to `busy`.
873 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
874 _Find more details on our JSDoc._
876 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
878 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
880 ### Pool options types declaration merge
882 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
884 #### New `export` strategy
888 const DynamicThreadPool = require('poolifier/lib/dynamic')
890 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
893 But you should always prefer just using
896 const { DynamicThreadPool } = require('poolifier')
899 #### New type definitions for input data and response
901 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
902 _This is not a limitation by poolifier but Node.js._
904 #### Public property replacements
906 `numWorkers` property is now `numberOfWorkers`
908 #### Internal (protected) properties and methods renaming
910 These properties are not intended for end users
912 - `id` => `nextMessageId`
914 These methods are not intended for end users
916 - `_chooseWorker` => `chooseWorker`
917 - `_newWorker` => `createWorker`
918 - `_execute` => `internalExecute`
919 - `_chooseWorker` => `chooseWorker`
920 - `_checkAlive` => `checkAlive`
922 - `_runAsync` => `runAsync`
924 ## [1.1.0] - 2020-05-21
928 - ThreadWorker support async functions as option
929 - Various external library patches
931 ## [1.0.0] - 2020-01-24
935 - FixedThreadPool implementation
936 - DynamicThreadPool implementation
937 - WorkerThread implementation to improve developer experience