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 race condition between ready and task functions worker message handling at startup.
13 - Fix duplicate task usage statistics computation per task function.
17 - Add back pressure detection on the worker node queue. Event `backPressure` is emitted when the worker node queue is full (size > poolMaxSize^2).
18 - Use back pressure detection in worker choice strategies.
19 - Add worker choice strategies retries mechanism if no worker is eligible.
21 ## [2.6.28] - 2023-08-16
25 - Ensure pool workers are properly initialized.
29 - HTTP server pool examples: express-cluster, express-hybrid.
33 - Remove now useless branching in worker hot code path.
35 ## [2.6.27] - 2023-08-15
39 - Add `KillHandler` type definition to exported types.
43 - Add `destroy` event to pool API.
45 ## [2.6.26] - 2023-08-15
49 - Add kill handler to worker options allowing to execute custom code when worker is killed.
50 - Add `listTaskFunctions()` method to pool API.
51 - SMTP server pool example: nodemailer.
53 ## [2.6.25] - 2023-08-13
57 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
58 - WebSocket server pool examples: ws-cluster, ws-hybrid.
60 ## [2.6.24] - 2023-08-12
64 - Add array of transferable objects to the `execute()` method arguments.
65 - WebSocket server pool examples: ws-worker_threads.
67 ## [2.6.23] - 2023-08-11
71 - 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.
75 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
76 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
78 ## [2.6.22] - 2023-08-10
82 - Add missing `types` field to package.json `exports`.
86 - Structure markdown documentation (PR #811).
88 ## [2.6.21] - 2023-08-03
92 - Improve code documentation.
93 - Code refactoring and cleanup for better maintainability and readability.
95 ## [2.6.20] - 2023-07-21
99 - Fix queued tasks redistribution on error task execution starvation.
100 - Ensure task queueing per worker condition is untangled from the pool busyness semantic.
104 - Drastically reduce lookups by worker in the worker nodes.
106 ## [2.6.19] - 2023-07-20
110 - Dedicated internal communication channel for worker_threads pools.
112 ## [2.6.18] - 2023-07-19
116 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
118 ## [2.6.17] - 2023-07-16
122 - Add `listTaskFunctions()` method to worker API.
124 ## [2.6.16] - 2023-07-12
128 - Fix pool startup detection.
129 - Fix worker task functions handling.
131 ## [2.6.15] - 2023-07-11
135 - Take into account worker node readiness in worker choice strategies.
137 ## [2.6.14] - 2023-07-10
141 - Fix task function statistics tracking.
143 ## [2.6.13] - 2023-07-10
147 - Add per task function statistics tracking.
148 - Add public methods to manipulate the worker task functions at runtime.
150 ## [2.6.12] - 2023-07-09
154 - Workaround import issue with `node:os` module in node 16.x.x.
156 ## [2.6.11] - 2023-07-09
160 - Fix pool readiness semantic.
162 ## [2.6.10] - 2023-07-08
166 - Ensure workers are not recreated on error at pool startup.
170 - Add `ready` and `strategy` fields to pool information.
171 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
172 - Add dynamic pool sizing checks.
174 ## [2.6.9] - 2023-07-07
178 - Recreate the right worker type on uncaught exception.
182 - Add minimum and maximum to internal measurement statistics.
183 - Add `runTime` and `waitTime` to pool information.
184 - Check worker inactive time only on dynamic worker.
186 ## [2.6.8] - 2023-07-03
190 - Brown paper bag release to fix version handling in pool information.
192 ## [2.6.7] - 2023-07-03
196 - Ensure worker queued tasks at error are reassigned to other pool workers.
200 - Add pool `utilization` ratio to pool information.
201 - Add `version` to pool information.
202 - Add worker information to worker nodes.
204 ## [2.6.6] - 2023-07-01
208 - Add safe helper `availableParallelism` to help sizing the pool.
212 - Ensure message handler is only registered in worker.
214 ## [2.6.5] - 2023-06-27
218 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
222 - Artificial version bump to 2.6.5 to workaround publication issue.
223 - Ensure cluster pool destroy() gracefully shutdowns worker's server.
224 - Ensure pool event is emitted before task error promise rejection.
225 - Fix queued tasks count computation.
229 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
231 ## [2.6.4] - 2023-06-27
235 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
239 - Ensure cluster pool destroy() gracefully shutdowns worker's server.
240 - Ensure pool event is emitted before task error promise rejection.
241 - Fix queued tasks count computation.
245 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
247 ## [2.6.3] - 2023-06-19
251 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
252 - Update strategies internals after statistics computation.
256 - Optimize O(1) queue implementation.
258 ## [2.6.2] - 2023-06-12
262 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
264 ## [2.6.1] - 2023-06-10
268 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
272 - Fix average statistics computation: ensure failed tasks are not accounted.
274 ## [2.6.0] - 2023-06-09
278 - Add `LEAST_ELU` worker choice strategy (experimental).
279 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
283 - Refactor pool worker node usage internals.
284 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
285 - Breaking change: pool information `info` property object fields have been renamed.
289 - Fix wait time accounting.
290 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
291 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
293 ## [2.5.4] - 2023-06-07
297 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
301 - Compute statistics at the worker level only if needed.
302 - Add `worker_threads` options to thread pool options.
306 - Make the `LEAST_BUSY` strategy only relies on task runtime.
308 ## [2.5.3] - 2023-06-04
312 - Refine pool information content.
313 - Limit pool internals public exposure.
315 ## [2.5.2] - 2023-06-02
319 - Add `taskError` pool event for task execution error.
320 - Add pool information `info` property to pool.
321 - Emit pool information on `busy` and `full` pool events.
323 ## [2.5.1] - 2023-06-01
327 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
328 - Add `error` pool event for uncaught worker error.
330 ## [2.5.0] - 2023-05-31
334 - Switch pool event emitter to `EventEmitterAsyncResource`.
335 - Add tasks wait time accounting in per worker tasks usage.
336 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
340 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
342 ## [2.4.14] - 2023-05-09
346 - Ensure no undefined task runtime can land in the tasks history.
347 - Fix median computation implementation once again.
351 - Unit tests for median and queue implementations.
353 ## [2.4.13] - 2023-05-08
357 - Fix worker choice strategy options validation.
358 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
360 ## [2.4.12] - 2023-05-06
364 - Support multiple task functions per worker.
365 - Add custom worker weights support to worker choice strategies options.
369 - Use O(1) queue implementation for tasks queueing.
373 - Fix median computation implementation.
374 - Fix fair share worker choice strategy internals update.
376 ## [2.4.11] - 2023-04-23
380 - Optimize free worker finding in worker choice strategies.
382 ## [2.4.10] - 2023-04-15
386 - Fix typescript type definition for task function: ensure the input data is optional.
387 - Fix typescript type definition for pool execute(): ensure the input data is optional.
389 ## [2.4.9] - 2023-04-15
393 - Add tasks queue enablement runtime setter to pool.
394 - Add tasks queue options runtime setter to pool.
395 - Add worker choice strategy options runtime setter to pool.
399 - Remove the tasks queuing experimental status.
403 - Fix task function type definition and validation.
404 - Fix worker choice strategy options handling.
406 ## [2.4.8] - 2023-04-12
410 - Fix message between main worker and worker type definition for tasks.
411 - Fix code documentation.
413 ## [2.4.7] - 2023-04-11
417 - Add worker tasks queue options to pool options.
421 - Fix missing documentation.
423 ## [2.4.6] - 2023-04-10
427 - Ensure one task at a time is executed per worker with tasks queueing enabled.
428 - Properly count worker executing tasks with tasks queueing enabled.
430 ## [2.4.5] - 2023-04-09
434 - Use monotonic high resolution timer for worker tasks runtime.
435 - Add worker tasks median runtime to statistics.
436 - Add worker tasks queue (experimental).
438 ## [2.4.4] - 2023-04-07
442 - Add `PoolEvents` enumeration and `PoolEvent` type.
446 - Destroy worker only on alive check.
448 ## [2.4.3] - 2023-04-07
452 - Fix typedoc generation with inheritance.
454 ## [2.4.2] - 2023-04-06
458 - Add `full` event to dynamic pool.
459 - Keep worker choice strategy in memory for conditional reuse.
463 - Fix possible negative worker key at worker removal in worker choice strategies.
465 ## [2.4.1] - 2023-04-05
469 - Optimize worker choice strategy for dynamic pool.
473 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
475 ## [2.4.0] - 2023-04-04
479 - Add `LESS_BUSY` worker choice strategy.
483 - Optimize worker storage in pool.
484 - Optimize worker alive status check.
485 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
486 - Optimize `LESS_USED` worker choice strategy.
487 - Update benchmarks versus external threads pools.
488 - Optimize tasks usage statistics requirements for worker choice strategy.
492 - Ensure trimmable characters are checked at pool initialization.
493 - Fix message id integer overflow.
494 - Fix pool worker removal in worker choice strategy internals.
495 - Fix package publication with pnpm.
497 ## [2.4.0-3] - 2023-04-04
501 - Add `LESS_BUSY` worker choice strategy.
505 - Optimize worker storage in pool.
506 - Optimize worker alive status check.
507 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
508 - Optimize `LESS_USED` worker choice strategy.
509 - Update benchmarks versus external threads pools.
513 - Ensure trimmable characters are checked at pool initialization.
514 - Fix message id integer overflow.
515 - Fix pool worker removal in worker choice strategy internals.
516 - Fix package publication with pnpm.
518 ## [2.4.0-2] - 2023-04-03
522 - Add `LESS_BUSY` worker choice strategy.
526 - Optimize worker storage in pool.
527 - Optimize worker alive status check.
528 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
529 - Optimize `LESS_USED` worker choice strategy.
533 - Ensure trimmable characters are checked at pool initialization.
534 - Fix message id integer overflow.
535 - Fix pool worker removal in worker choice strategy internals.
536 - Fix package publication with pnpm.
538 ## [2.4.0-1] - 2023-04-03
542 - Add `LESS_BUSY` worker choice strategy.
546 - Optimize worker storage in pool.
547 - Optimize worker alive status check.
548 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
549 - Optimize `LESS_USED` worker choice strategy.
553 - Ensure trimmable characters are checked at pool initialization.
554 - Fix message id integer overflow.
555 - Fix pool worker removal in worker choice strategy internals.
557 ## [2.4.0-0] - 2023-04-03
561 - Add `LESS_BUSY` worker choice strategy.
565 - Optimize worker storage in pool.
566 - Optimize worker alive status check.
567 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
568 - Optimize `LESS_USED` worker choice strategy.
572 - Ensure trimmable characters are checked at pool initialization.
573 - Fix message id integer overflow.
574 - Fix pool worker removal in worker choice strategy internals.
576 ## [2.3.10] - 2023-03-18
580 - Fix package.json `exports` syntax for ESM and CommonJS.
584 - Permit SemVer pre-release publication.
586 ## [2.3.10-2] - 2023-03-18
590 - Fix package.json `exports` syntax for ESM and CommonJS.
592 ## [2.3.10-1] - 2023-03-18
596 - Permit SemVer pre-release publication.
598 ## [2.3.10-0] - 2023-03-18
602 - Fix package.json `exports` syntax for ESM and CommonJS.
604 ## [2.3.9] - 2023-03-18
608 - Introduce ESM module support along with CommonJS one.
612 - Fix brown paper bag bug referencing the same object literal.
614 ## [2.3.8] - 2023-03-18
618 - Switch internal benchmarking code to benny.
619 - Switch to TypeScript 5.x.x.
620 - Switch rollup bundler plugins to core ones.
621 - Switch to TSDoc syntax.
622 - Enforce conventional commits.
626 - Fix random integer generator.
627 - Fix worker choice strategy pool type identification at initialization.
629 ## [2.3.7] - 2022-10-23
633 - Switch to open collective FOSS project funding platform.
634 - Switch to ts-standard linter configuration on TypeScript code.
638 - Fixed missing async on pool execute method.
639 - Fixed typing in TypeScript example.
640 - Fixed types in unit tests.
642 ## [2.3.6] - 2022-10-22
646 - Cleanup pool attributes and methods.
647 - Refine error types thrown.
651 - Fix continuous integration build on windows.
652 - Fix code coverage reporting by using c8 instead of nyc.
654 ## [2.3.5] - 2022-10-21
658 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
659 - Optimize tasks usage lookup implementation.
663 - Fix missed pool event emitter type export.
664 - Fix typedoc documentation generation.
666 ## [2.3.4] - 2022-10-17
670 - Fully automate release process with release-it.
674 - Optimize fair share task scheduling algorithm implementation.
675 - Update benchmarks versus external pools results with latest version.
677 ## [2.3.3] - 2022-10-15
681 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
683 ## [2.3.2] - 2022-10-14
687 - Optimize fair share worker selection strategy implementation.
691 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
693 ## [2.3.1] - 2022-10-13
697 - Pool worker choice strategies:
698 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
699 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
701 ## [2.2.2] - 2022-10-09
705 - Fixed `README.md` file.
707 ## [2.2.1] - 2022-10-08
711 - Dynamic worker choice strategy change at runtime.
713 ## [2.2.0] - 2022-01-05
717 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
719 ## [2.1.0] - 2021-08-29
723 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
727 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
728 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
729 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
730 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
732 ## [2.0.2] - 2021-05-12
736 - Fix `busy` event emission on fixed pool type
738 ## [2.0.1] - 2021-03-16
742 - Check if pool options are properly set.
743 - `busy` event is emitted on all pool types.
745 ## [2.0.0] - 2021-03-01
749 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
753 - `FullPool` event is now renamed to `busy`.
754 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
755 _Find more details on our JSDoc._
757 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
759 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
761 ### Pool options types declaration merge
763 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
765 #### New `export` strategy
769 const DynamicThreadPool = require('poolifier/lib/dynamic')
771 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
774 But you should always prefer just using
777 const { DynamicThreadPool } = require('poolifier')
780 #### New type definitions for input data and response
782 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
783 _This is not a limitation by poolifier but Node.js._
785 #### Public property replacements
787 `numWorkers` property is now `numberOfWorkers`
789 #### Internal (protected) properties and methods renaming
791 These properties are not intended for end users
793 - `id` => `nextMessageId`
795 These methods are not intended for end users
797 - `_chooseWorker` => `chooseWorker`
798 - `_newWorker` => `createWorker`
799 - `_execute` => `internalExecute`
800 - `_chooseWorker` => `chooseWorker`
801 - `_checkAlive` => `checkAlive`
803 - `_runAsync` => `runAsync`
805 ## [1.1.0] - 2020-05-21
809 - ThreadWorker support async functions as option
810 - Various external library patches
812 ## [1.0.0] - 2020-01-24
816 - FixedThreadPool implementation
817 - DynamicThreadPool implementation
818 - WorkerThread implementation to improve developer experience