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 ## [2.6.34] - 2023-08-24
14 - Avoid cascading tasks stealing under back pressure.
18 - Add fastpath to queued tasks rescheduling.
20 ## [2.6.33] - 2023-08-24
24 - Fix queued tasks rescheduling.
28 - Rename tasks queue options `queueMaxSize` to `size`.
32 - Task stealing scheduling algorithm if tasks queueing is enabled.
34 ## [2.6.32] - 2023-08-23
38 - Ensure no task can be executed when the pool is destroyed.
42 - Add `queueMaxSize` option to tasks queue options.
43 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
44 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
46 ## [2.6.31] - 2023-08-20
50 - Fix worker choice strategy retries mechanism in some edge cases.
54 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
55 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
57 ## [2.6.30] - 2023-08-19
61 - Ensure pool event `backPressure` is emitted.
62 - Ensure pool event `full` is emitted only once.
63 - Ensure worker node cannot be instantiated without proper arguments.
65 ## [2.6.29] - 2023-08-18
69 - Fix race condition between ready and task functions worker message handling at startup.
70 - Fix duplicate task function worker usage statistics computation per task function.
71 - Update task function worker usage statistics if and only if there's at least two different task functions.
72 - Fix race condition at task function worker usage executing task computation leading to negative value.
76 - 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).
77 - Use back pressure detection in worker choice strategies.
78 - Add worker choice strategies retries mechanism if no worker is eligible.
80 ## [2.6.28] - 2023-08-16
84 - Ensure pool workers are properly initialized.
88 - HTTP server pool examples: express-cluster, express-hybrid.
92 - Remove now useless branching in worker hot code path.
94 ## [2.6.27] - 2023-08-15
98 - Add `KillHandler` type definition to exported types.
102 - Add `destroy` event to pool API.
104 ## [2.6.26] - 2023-08-15
108 - Add kill handler to worker options allowing to execute custom code when worker is killed.
109 - Add `listTaskFunctions()` method to pool API.
110 - SMTP server pool example: nodemailer.
112 ## [2.6.25] - 2023-08-13
116 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
117 - WebSocket server pool examples: ws-cluster, ws-hybrid.
119 ## [2.6.24] - 2023-08-12
123 - Add array of transferable objects to the `execute()` method arguments.
124 - WebSocket server pool examples: ws-worker_threads.
126 ## [2.6.23] - 2023-08-11
130 - 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.
134 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
135 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
137 ## [2.6.22] - 2023-08-10
141 - Add missing `types` field to package.json `exports`.
145 - Structure markdown documentation (PR #811).
147 ## [2.6.21] - 2023-08-03
151 - Improve code documentation.
152 - Code refactoring and cleanup for better maintainability and readability.
154 ## [2.6.20] - 2023-07-21
158 - Fix queued tasks redistribution on error task execution starvation.
159 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
163 - Drastically reduce lookups by worker in the worker nodes.
165 ## [2.6.19] - 2023-07-20
169 - Dedicated internal communication channel for worker_threads pools.
171 ## [2.6.18] - 2023-07-19
175 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
177 ## [2.6.17] - 2023-07-16
181 - Add `listTaskFunctions()` method to worker API.
183 ## [2.6.16] - 2023-07-12
187 - Fix pool startup detection.
188 - Fix worker task functions handling.
190 ## [2.6.15] - 2023-07-11
194 - Take into account worker node readiness in worker choice strategies.
196 ## [2.6.14] - 2023-07-10
200 - Fix task function statistics tracking.
202 ## [2.6.13] - 2023-07-10
206 - Add per task function statistics tracking.
207 - Add public methods to manipulate the worker task functions at runtime.
209 ## [2.6.12] - 2023-07-09
213 - Workaround import issue with `node:os` module in node 16.x.x.
215 ## [2.6.11] - 2023-07-09
219 - Fix pool readiness semantic.
221 ## [2.6.10] - 2023-07-08
225 - Ensure workers are not recreated on error at pool startup.
229 - Add `ready` and `strategy` fields to pool information.
230 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
231 - Add dynamic pool sizing checks.
233 ## [2.6.9] - 2023-07-07
237 - Recreate the right worker type on uncaught exception.
241 - Add minimum and maximum to internal measurement statistics.
242 - Add `runTime` and `waitTime` to pool information.
243 - Check worker inactive time only on dynamic worker.
245 ## [2.6.8] - 2023-07-03
249 - Brown paper bag release to fix version handling in pool information.
251 ## [2.6.7] - 2023-07-03
255 - Ensure worker queued tasks at error are reassigned to other pool workers.
259 - Add pool `utilization` ratio to pool information.
260 - Add `version` to pool information.
261 - Add worker information to worker nodes.
263 ## [2.6.6] - 2023-07-01
267 - Add safe helper `availableParallelism()` to help sizing the pool.
271 - Ensure message handler is only registered in worker.
273 ## [2.6.5] - 2023-06-27
277 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
281 - Artificial version bump to 2.6.5 to workaround publication issue.
282 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
283 - Ensure pool event is emitted before task error promise rejection.
284 - Fix queued tasks count computation.
288 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
290 ## [2.6.4] - 2023-06-27
294 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
298 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
299 - Ensure pool event is emitted before task error promise rejection.
300 - Fix queued tasks count computation.
304 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
306 ## [2.6.3] - 2023-06-19
310 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
311 - Update strategies internals after statistics computation.
315 - Optimize O(1) queue implementation.
317 ## [2.6.2] - 2023-06-12
321 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
323 ## [2.6.1] - 2023-06-10
327 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
331 - Fix average statistics computation: ensure failed tasks are not accounted.
333 ## [2.6.0] - 2023-06-09
337 - Add `LEAST_ELU` worker choice strategy (experimental).
338 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
342 - Refactor pool worker node usage internals.
343 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
344 - Breaking change: pool information `info` property object fields have been renamed.
348 - Fix wait time accounting.
349 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
350 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
352 ## [2.5.4] - 2023-06-07
356 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
360 - Compute statistics at the worker level only if needed.
361 - Add `worker_threads` options to thread pool options.
365 - Make the `LEAST_BUSY` strategy only relies on task runtime.
367 ## [2.5.3] - 2023-06-04
371 - Refine pool information content.
372 - Limit pool internals public exposure.
374 ## [2.5.2] - 2023-06-02
378 - Add `taskError` pool event for task execution error.
379 - Add pool information `info` property to pool.
380 - Emit pool information on `busy` and `full` pool events.
382 ## [2.5.1] - 2023-06-01
386 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
387 - Add `error` pool event for uncaught worker error.
389 ## [2.5.0] - 2023-05-31
393 - Switch pool event emitter to `EventEmitterAsyncResource`.
394 - Add tasks wait time accounting in per worker tasks usage.
395 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
399 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
401 ## [2.4.14] - 2023-05-09
405 - Ensure no undefined task runtime can land in the tasks history.
406 - Fix median computation implementation once again.
410 - Unit tests for median and queue implementations.
412 ## [2.4.13] - 2023-05-08
416 - Fix worker choice strategy options validation.
417 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
419 ## [2.4.12] - 2023-05-06
423 - Support multiple task functions per worker.
424 - Add custom worker weights support to worker choice strategies options.
428 - Use O(1) queue implementation for tasks queueing.
432 - Fix median computation implementation.
433 - Fix fair share worker choice strategy internals update.
435 ## [2.4.11] - 2023-04-23
439 - Optimize free worker finding in worker choice strategies.
441 ## [2.4.10] - 2023-04-15
445 - Fix typescript type definition for task function: ensure the input data is optional.
446 - Fix typescript type definition for pool execute(): ensure the input data is optional.
448 ## [2.4.9] - 2023-04-15
452 - Add tasks queue enablement runtime setter to pool.
453 - Add tasks queue options runtime setter to pool.
454 - Add worker choice strategy options runtime setter to pool.
458 - Remove the tasks queuing experimental status.
462 - Fix task function type definition and validation.
463 - Fix worker choice strategy options handling.
465 ## [2.4.8] - 2023-04-12
469 - Fix message between main worker and worker type definition for tasks.
470 - Fix code documentation.
472 ## [2.4.7] - 2023-04-11
476 - Add worker tasks queue options to pool options.
480 - Fix missing documentation.
482 ## [2.4.6] - 2023-04-10
486 - Ensure one task at a time is executed per worker with tasks queueing enabled.
487 - Properly count worker executing tasks with tasks queueing enabled.
489 ## [2.4.5] - 2023-04-09
493 - Use monotonic high resolution timer for worker tasks runtime.
494 - Add worker tasks median runtime to statistics.
495 - Add worker tasks queue (experimental).
497 ## [2.4.4] - 2023-04-07
501 - Add `PoolEvents` enumeration and `PoolEvent` type.
505 - Destroy worker only on alive check.
507 ## [2.4.3] - 2023-04-07
511 - Fix typedoc generation with inheritance.
513 ## [2.4.2] - 2023-04-06
517 - Add `full` event to dynamic pool.
518 - Keep worker choice strategy in memory for conditional reuse.
522 - Fix possible negative worker key at worker removal in worker choice strategies.
524 ## [2.4.1] - 2023-04-05
528 - Optimize worker choice strategy for dynamic pool.
532 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
534 ## [2.4.0] - 2023-04-04
538 - Add `LESS_BUSY` worker choice strategy.
542 - Optimize worker storage in pool.
543 - Optimize worker alive status check.
544 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
545 - Optimize `LESS_USED` worker choice strategy.
546 - Update benchmarks versus external threads pools.
547 - Optimize tasks usage statistics requirements for worker choice strategy.
551 - Ensure trimmable characters are checked at pool initialization.
552 - Fix message id integer overflow.
553 - Fix pool worker removal in worker choice strategy internals.
554 - Fix package publication with pnpm.
556 ## [2.4.0-3] - 2023-04-04
560 - Add `LESS_BUSY` worker choice strategy.
564 - Optimize worker storage in pool.
565 - Optimize worker alive status check.
566 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
567 - Optimize `LESS_USED` worker choice strategy.
568 - Update benchmarks versus external threads pools.
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.
575 - Fix package publication with pnpm.
577 ## [2.4.0-2] - 2023-04-03
581 - Add `LESS_BUSY` worker choice strategy.
585 - Optimize worker storage in pool.
586 - Optimize worker alive status check.
587 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
588 - Optimize `LESS_USED` worker choice strategy.
592 - Ensure trimmable characters are checked at pool initialization.
593 - Fix message id integer overflow.
594 - Fix pool worker removal in worker choice strategy internals.
595 - Fix package publication with pnpm.
597 ## [2.4.0-1] - 2023-04-03
601 - Add `LESS_BUSY` worker choice strategy.
605 - Optimize worker storage in pool.
606 - Optimize worker alive status check.
607 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
608 - Optimize `LESS_USED` worker choice strategy.
612 - Ensure trimmable characters are checked at pool initialization.
613 - Fix message id integer overflow.
614 - Fix pool worker removal in worker choice strategy internals.
616 ## [2.4.0-0] - 2023-04-03
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.
631 - Ensure trimmable characters are checked at pool initialization.
632 - Fix message id integer overflow.
633 - Fix pool worker removal in worker choice strategy internals.
635 ## [2.3.10] - 2023-03-18
639 - Fix package.json `exports` syntax for ESM and CommonJS.
643 - Permit SemVer pre-release publication.
645 ## [2.3.10-2] - 2023-03-18
649 - Fix package.json `exports` syntax for ESM and CommonJS.
651 ## [2.3.10-1] - 2023-03-18
655 - Permit SemVer pre-release publication.
657 ## [2.3.10-0] - 2023-03-18
661 - Fix package.json `exports` syntax for ESM and CommonJS.
663 ## [2.3.9] - 2023-03-18
667 - Introduce ESM module support along with CommonJS one.
671 - Fix brown paper bag bug referencing the same object literal.
673 ## [2.3.8] - 2023-03-18
677 - Switch internal benchmarking code to benny.
678 - Switch to TypeScript 5.x.x.
679 - Switch rollup bundler plugins to core ones.
680 - Switch to TSDoc syntax.
681 - Enforce conventional commits.
685 - Fix random integer generator.
686 - Fix worker choice strategy pool type identification at initialization.
688 ## [2.3.7] - 2022-10-23
692 - Switch to open collective FOSS project funding platform.
693 - Switch to ts-standard linter configuration on TypeScript code.
697 - Fixed missing async on pool execute method.
698 - Fixed typing in TypeScript example.
699 - Fixed types in unit tests.
701 ## [2.3.6] - 2022-10-22
705 - Cleanup pool attributes and methods.
706 - Refine error types thrown.
710 - Fix continuous integration build on windows.
711 - Fix code coverage reporting by using c8 instead of nyc.
713 ## [2.3.5] - 2022-10-21
717 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
718 - Optimize tasks usage lookup implementation.
722 - Fix missed pool event emitter type export.
723 - Fix typedoc documentation generation.
725 ## [2.3.4] - 2022-10-17
729 - Fully automate release process with release-it.
733 - Optimize fair share task scheduling algorithm implementation.
734 - Update benchmarks versus external pools results with latest version.
736 ## [2.3.3] - 2022-10-15
740 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
742 ## [2.3.2] - 2022-10-14
746 - Optimize fair share worker selection strategy implementation.
750 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
752 ## [2.3.1] - 2022-10-13
756 - Pool worker choice strategies:
757 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
758 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
760 ## [2.2.2] - 2022-10-09
764 - Fixed `README.md` file.
766 ## [2.2.1] - 2022-10-08
770 - Dynamic worker choice strategy change at runtime.
772 ## [2.2.0] - 2022-01-05
776 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
778 ## [2.1.0] - 2021-08-29
782 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
786 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
787 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
788 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
789 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
791 ## [2.0.2] - 2021-05-12
795 - Fix `busy` event emission on fixed pool type
797 ## [2.0.1] - 2021-03-16
801 - Check if pool options are properly set.
802 - `busy` event is emitted on all pool types.
804 ## [2.0.0] - 2021-03-01
808 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
812 - `FullPool` event is now renamed to `busy`.
813 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
814 _Find more details on our JSDoc._
816 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
818 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
820 ### Pool options types declaration merge
822 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
824 #### New `export` strategy
828 const DynamicThreadPool = require('poolifier/lib/dynamic')
830 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
833 But you should always prefer just using
836 const { DynamicThreadPool } = require('poolifier')
839 #### New type definitions for input data and response
841 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
842 _This is not a limitation by poolifier but Node.js._
844 #### Public property replacements
846 `numWorkers` property is now `numberOfWorkers`
848 #### Internal (protected) properties and methods renaming
850 These properties are not intended for end users
852 - `id` => `nextMessageId`
854 These methods are not intended for end users
856 - `_chooseWorker` => `chooseWorker`
857 - `_newWorker` => `createWorker`
858 - `_execute` => `internalExecute`
859 - `_chooseWorker` => `chooseWorker`
860 - `_checkAlive` => `checkAlive`
862 - `_runAsync` => `runAsync`
864 ## [1.1.0] - 2020-05-21
868 - ThreadWorker support async functions as option
869 - Various external library patches
871 ## [1.0.0] - 2020-01-24
875 - FixedThreadPool implementation
876 - DynamicThreadPool implementation
877 - WorkerThread implementation to improve developer experience