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 - Fix queued tasks rescheduling.
16 - Rename tasks queue options `queueMaxSize` to `size`.
20 - Task stealing scheduling algorithm if tasks queueing is enabled.
22 ## [2.6.32] - 2023-08-23
26 - Ensure no task can be executed when the pool is destroyed.
30 - Add `queueMaxSize` option to tasks queue options.
31 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
32 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
34 ## [2.6.31] - 2023-08-20
38 - Fix worker choice strategy retries mechanism in some edge cases.
42 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
43 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
45 ## [2.6.30] - 2023-08-19
49 - Ensure pool event `backPressure` is emitted.
50 - Ensure pool event `full` is emitted only once.
51 - Ensure worker node cannot be instantiated without proper arguments.
53 ## [2.6.29] - 2023-08-18
57 - Fix race condition between ready and task functions worker message handling at startup.
58 - Fix duplicate task function worker usage statistics computation per task function.
59 - Update task function worker usage statistics if and only if there's at least two different task functions.
60 - Fix race condition at task function worker usage executing task computation leading to negative value.
64 - 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).
65 - Use back pressure detection in worker choice strategies.
66 - Add worker choice strategies retries mechanism if no worker is eligible.
68 ## [2.6.28] - 2023-08-16
72 - Ensure pool workers are properly initialized.
76 - HTTP server pool examples: express-cluster, express-hybrid.
80 - Remove now useless branching in worker hot code path.
82 ## [2.6.27] - 2023-08-15
86 - Add `KillHandler` type definition to exported types.
90 - Add `destroy` event to pool API.
92 ## [2.6.26] - 2023-08-15
96 - Add kill handler to worker options allowing to execute custom code when worker is killed.
97 - Add `listTaskFunctions()` method to pool API.
98 - SMTP server pool example: nodemailer.
100 ## [2.6.25] - 2023-08-13
104 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
105 - WebSocket server pool examples: ws-cluster, ws-hybrid.
107 ## [2.6.24] - 2023-08-12
111 - Add array of transferable objects to the `execute()` method arguments.
112 - WebSocket server pool examples: ws-worker_threads.
114 ## [2.6.23] - 2023-08-11
118 - 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.
122 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
123 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
125 ## [2.6.22] - 2023-08-10
129 - Add missing `types` field to package.json `exports`.
133 - Structure markdown documentation (PR #811).
135 ## [2.6.21] - 2023-08-03
139 - Improve code documentation.
140 - Code refactoring and cleanup for better maintainability and readability.
142 ## [2.6.20] - 2023-07-21
146 - Fix queued tasks redistribution on error task execution starvation.
147 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
151 - Drastically reduce lookups by worker in the worker nodes.
153 ## [2.6.19] - 2023-07-20
157 - Dedicated internal communication channel for worker_threads pools.
159 ## [2.6.18] - 2023-07-19
163 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
165 ## [2.6.17] - 2023-07-16
169 - Add `listTaskFunctions()` method to worker API.
171 ## [2.6.16] - 2023-07-12
175 - Fix pool startup detection.
176 - Fix worker task functions handling.
178 ## [2.6.15] - 2023-07-11
182 - Take into account worker node readiness in worker choice strategies.
184 ## [2.6.14] - 2023-07-10
188 - Fix task function statistics tracking.
190 ## [2.6.13] - 2023-07-10
194 - Add per task function statistics tracking.
195 - Add public methods to manipulate the worker task functions at runtime.
197 ## [2.6.12] - 2023-07-09
201 - Workaround import issue with `node:os` module in node 16.x.x.
203 ## [2.6.11] - 2023-07-09
207 - Fix pool readiness semantic.
209 ## [2.6.10] - 2023-07-08
213 - Ensure workers are not recreated on error at pool startup.
217 - Add `ready` and `strategy` fields to pool information.
218 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
219 - Add dynamic pool sizing checks.
221 ## [2.6.9] - 2023-07-07
225 - Recreate the right worker type on uncaught exception.
229 - Add minimum and maximum to internal measurement statistics.
230 - Add `runTime` and `waitTime` to pool information.
231 - Check worker inactive time only on dynamic worker.
233 ## [2.6.8] - 2023-07-03
237 - Brown paper bag release to fix version handling in pool information.
239 ## [2.6.7] - 2023-07-03
243 - Ensure worker queued tasks at error are reassigned to other pool workers.
247 - Add pool `utilization` ratio to pool information.
248 - Add `version` to pool information.
249 - Add worker information to worker nodes.
251 ## [2.6.6] - 2023-07-01
255 - Add safe helper `availableParallelism()` to help sizing the pool.
259 - Ensure message handler is only registered in worker.
261 ## [2.6.5] - 2023-06-27
265 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
269 - Artificial version bump to 2.6.5 to workaround publication issue.
270 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
271 - Ensure pool event is emitted before task error promise rejection.
272 - Fix queued tasks count computation.
276 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
278 ## [2.6.4] - 2023-06-27
282 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
286 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
287 - Ensure pool event is emitted before task error promise rejection.
288 - Fix queued tasks count computation.
292 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
294 ## [2.6.3] - 2023-06-19
298 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
299 - Update strategies internals after statistics computation.
303 - Optimize O(1) queue implementation.
305 ## [2.6.2] - 2023-06-12
309 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
311 ## [2.6.1] - 2023-06-10
315 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
319 - Fix average statistics computation: ensure failed tasks are not accounted.
321 ## [2.6.0] - 2023-06-09
325 - Add `LEAST_ELU` worker choice strategy (experimental).
326 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
330 - Refactor pool worker node usage internals.
331 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
332 - Breaking change: pool information `info` property object fields have been renamed.
336 - Fix wait time accounting.
337 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
338 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
340 ## [2.5.4] - 2023-06-07
344 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
348 - Compute statistics at the worker level only if needed.
349 - Add `worker_threads` options to thread pool options.
353 - Make the `LEAST_BUSY` strategy only relies on task runtime.
355 ## [2.5.3] - 2023-06-04
359 - Refine pool information content.
360 - Limit pool internals public exposure.
362 ## [2.5.2] - 2023-06-02
366 - Add `taskError` pool event for task execution error.
367 - Add pool information `info` property to pool.
368 - Emit pool information on `busy` and `full` pool events.
370 ## [2.5.1] - 2023-06-01
374 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
375 - Add `error` pool event for uncaught worker error.
377 ## [2.5.0] - 2023-05-31
381 - Switch pool event emitter to `EventEmitterAsyncResource`.
382 - Add tasks wait time accounting in per worker tasks usage.
383 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
387 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
389 ## [2.4.14] - 2023-05-09
393 - Ensure no undefined task runtime can land in the tasks history.
394 - Fix median computation implementation once again.
398 - Unit tests for median and queue implementations.
400 ## [2.4.13] - 2023-05-08
404 - Fix worker choice strategy options validation.
405 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
407 ## [2.4.12] - 2023-05-06
411 - Support multiple task functions per worker.
412 - Add custom worker weights support to worker choice strategies options.
416 - Use O(1) queue implementation for tasks queueing.
420 - Fix median computation implementation.
421 - Fix fair share worker choice strategy internals update.
423 ## [2.4.11] - 2023-04-23
427 - Optimize free worker finding in worker choice strategies.
429 ## [2.4.10] - 2023-04-15
433 - Fix typescript type definition for task function: ensure the input data is optional.
434 - Fix typescript type definition for pool execute(): ensure the input data is optional.
436 ## [2.4.9] - 2023-04-15
440 - Add tasks queue enablement runtime setter to pool.
441 - Add tasks queue options runtime setter to pool.
442 - Add worker choice strategy options runtime setter to pool.
446 - Remove the tasks queuing experimental status.
450 - Fix task function type definition and validation.
451 - Fix worker choice strategy options handling.
453 ## [2.4.8] - 2023-04-12
457 - Fix message between main worker and worker type definition for tasks.
458 - Fix code documentation.
460 ## [2.4.7] - 2023-04-11
464 - Add worker tasks queue options to pool options.
468 - Fix missing documentation.
470 ## [2.4.6] - 2023-04-10
474 - Ensure one task at a time is executed per worker with tasks queueing enabled.
475 - Properly count worker executing tasks with tasks queueing enabled.
477 ## [2.4.5] - 2023-04-09
481 - Use monotonic high resolution timer for worker tasks runtime.
482 - Add worker tasks median runtime to statistics.
483 - Add worker tasks queue (experimental).
485 ## [2.4.4] - 2023-04-07
489 - Add `PoolEvents` enumeration and `PoolEvent` type.
493 - Destroy worker only on alive check.
495 ## [2.4.3] - 2023-04-07
499 - Fix typedoc generation with inheritance.
501 ## [2.4.2] - 2023-04-06
505 - Add `full` event to dynamic pool.
506 - Keep worker choice strategy in memory for conditional reuse.
510 - Fix possible negative worker key at worker removal in worker choice strategies.
512 ## [2.4.1] - 2023-04-05
516 - Optimize worker choice strategy for dynamic pool.
520 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
522 ## [2.4.0] - 2023-04-04
526 - Add `LESS_BUSY` worker choice strategy.
530 - Optimize worker storage in pool.
531 - Optimize worker alive status check.
532 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
533 - Optimize `LESS_USED` worker choice strategy.
534 - Update benchmarks versus external threads pools.
535 - Optimize tasks usage statistics requirements for worker choice strategy.
539 - Ensure trimmable characters are checked at pool initialization.
540 - Fix message id integer overflow.
541 - Fix pool worker removal in worker choice strategy internals.
542 - Fix package publication with pnpm.
544 ## [2.4.0-3] - 2023-04-04
548 - Add `LESS_BUSY` worker choice strategy.
552 - Optimize worker storage in pool.
553 - Optimize worker alive status check.
554 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
555 - Optimize `LESS_USED` worker choice strategy.
556 - Update benchmarks versus external threads pools.
560 - Ensure trimmable characters are checked at pool initialization.
561 - Fix message id integer overflow.
562 - Fix pool worker removal in worker choice strategy internals.
563 - Fix package publication with pnpm.
565 ## [2.4.0-2] - 2023-04-03
569 - Add `LESS_BUSY` worker choice strategy.
573 - Optimize worker storage in pool.
574 - Optimize worker alive status check.
575 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
576 - Optimize `LESS_USED` worker choice strategy.
580 - Ensure trimmable characters are checked at pool initialization.
581 - Fix message id integer overflow.
582 - Fix pool worker removal in worker choice strategy internals.
583 - Fix package publication with pnpm.
585 ## [2.4.0-1] - 2023-04-03
589 - Add `LESS_BUSY` worker choice strategy.
593 - Optimize worker storage in pool.
594 - Optimize worker alive status check.
595 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
596 - Optimize `LESS_USED` worker choice strategy.
600 - Ensure trimmable characters are checked at pool initialization.
601 - Fix message id integer overflow.
602 - Fix pool worker removal in worker choice strategy internals.
604 ## [2.4.0-0] - 2023-04-03
608 - Add `LESS_BUSY` worker choice strategy.
612 - Optimize worker storage in pool.
613 - Optimize worker alive status check.
614 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
615 - Optimize `LESS_USED` 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.
623 ## [2.3.10] - 2023-03-18
627 - Fix package.json `exports` syntax for ESM and CommonJS.
631 - Permit SemVer pre-release publication.
633 ## [2.3.10-2] - 2023-03-18
637 - Fix package.json `exports` syntax for ESM and CommonJS.
639 ## [2.3.10-1] - 2023-03-18
643 - Permit SemVer pre-release publication.
645 ## [2.3.10-0] - 2023-03-18
649 - Fix package.json `exports` syntax for ESM and CommonJS.
651 ## [2.3.9] - 2023-03-18
655 - Introduce ESM module support along with CommonJS one.
659 - Fix brown paper bag bug referencing the same object literal.
661 ## [2.3.8] - 2023-03-18
665 - Switch internal benchmarking code to benny.
666 - Switch to TypeScript 5.x.x.
667 - Switch rollup bundler plugins to core ones.
668 - Switch to TSDoc syntax.
669 - Enforce conventional commits.
673 - Fix random integer generator.
674 - Fix worker choice strategy pool type identification at initialization.
676 ## [2.3.7] - 2022-10-23
680 - Switch to open collective FOSS project funding platform.
681 - Switch to ts-standard linter configuration on TypeScript code.
685 - Fixed missing async on pool execute method.
686 - Fixed typing in TypeScript example.
687 - Fixed types in unit tests.
689 ## [2.3.6] - 2022-10-22
693 - Cleanup pool attributes and methods.
694 - Refine error types thrown.
698 - Fix continuous integration build on windows.
699 - Fix code coverage reporting by using c8 instead of nyc.
701 ## [2.3.5] - 2022-10-21
705 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
706 - Optimize tasks usage lookup implementation.
710 - Fix missed pool event emitter type export.
711 - Fix typedoc documentation generation.
713 ## [2.3.4] - 2022-10-17
717 - Fully automate release process with release-it.
721 - Optimize fair share task scheduling algorithm implementation.
722 - Update benchmarks versus external pools results with latest version.
724 ## [2.3.3] - 2022-10-15
728 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
730 ## [2.3.2] - 2022-10-14
734 - Optimize fair share worker selection strategy implementation.
738 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
740 ## [2.3.1] - 2022-10-13
744 - Pool worker choice strategies:
745 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
746 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
748 ## [2.2.2] - 2022-10-09
752 - Fixed `README.md` file.
754 ## [2.2.1] - 2022-10-08
758 - Dynamic worker choice strategy change at runtime.
760 ## [2.2.0] - 2022-01-05
764 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
766 ## [2.1.0] - 2021-08-29
770 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
774 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
775 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
776 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
777 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
779 ## [2.0.2] - 2021-05-12
783 - Fix `busy` event emission on fixed pool type
785 ## [2.0.1] - 2021-03-16
789 - Check if pool options are properly set.
790 - `busy` event is emitted on all pool types.
792 ## [2.0.0] - 2021-03-01
796 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
800 - `FullPool` event is now renamed to `busy`.
801 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
802 _Find more details on our JSDoc._
804 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
806 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
808 ### Pool options types declaration merge
810 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
812 #### New `export` strategy
816 const DynamicThreadPool = require('poolifier/lib/dynamic')
818 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
821 But you should always prefer just using
824 const { DynamicThreadPool } = require('poolifier')
827 #### New type definitions for input data and response
829 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
830 _This is not a limitation by poolifier but Node.js._
832 #### Public property replacements
834 `numWorkers` property is now `numberOfWorkers`
836 #### Internal (protected) properties and methods renaming
838 These properties are not intended for end users
840 - `id` => `nextMessageId`
842 These methods are not intended for end users
844 - `_chooseWorker` => `chooseWorker`
845 - `_newWorker` => `createWorker`
846 - `_execute` => `internalExecute`
847 - `_chooseWorker` => `chooseWorker`
848 - `_checkAlive` => `checkAlive`
850 - `_runAsync` => `runAsync`
852 ## [1.1.0] - 2020-05-21
856 - ThreadWorker support async functions as option
857 - Various external library patches
859 ## [1.0.0] - 2020-01-24
863 - FixedThreadPool implementation
864 - DynamicThreadPool implementation
865 - WorkerThread implementation to improve developer experience