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 - Make continuous tasks stealing algorithm less aggressive.
13 - Fine tune tasks stealing algorithm under back pressure.
15 ## [2.6.35] - 2023-08-25
19 - Don't account worker usage statistics for tasks that have failed.
20 - Fix pool information runtime and wait time median computation.
24 - Update simple moving average implementation to use a circular buffer.
25 - Update simple moving median implementation to use a circular buffer.
26 - Account for stolen tasks in worker usage statistics and pool information.
30 - Continuous tasks stealing algorithm.
32 ## [2.6.34] - 2023-08-24
36 - Avoid cascading tasks stealing under back pressure.
40 - Add fastpath to queued tasks rescheduling.
42 ## [2.6.33] - 2023-08-24
46 - Fix queued tasks rescheduling.
50 - Rename tasks queue options `queueMaxSize` to `size`.
54 - Task stealing scheduling algorithm if tasks queueing is enabled.
56 ## [2.6.32] - 2023-08-23
60 - Ensure no task can be executed when the pool is destroyed.
64 - Add `queueMaxSize` option to tasks queue options.
65 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
66 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
68 ## [2.6.31] - 2023-08-20
72 - Fix worker choice strategy retries mechanism in some edge cases.
76 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
77 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
79 ## [2.6.30] - 2023-08-19
83 - Ensure pool event `backPressure` is emitted.
84 - Ensure pool event `full` is emitted only once.
85 - Ensure worker node cannot be instantiated without proper arguments.
87 ## [2.6.29] - 2023-08-18
91 - Fix race condition between ready and task functions worker message handling at startup.
92 - Fix duplicate task function worker usage statistics computation per task function.
93 - Update task function worker usage statistics if and only if there's at least two different task functions.
94 - Fix race condition at task function worker usage executing task computation leading to negative value.
98 - 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).
99 - Use back pressure detection in worker choice strategies.
100 - Add worker choice strategies retries mechanism if no worker is eligible.
102 ## [2.6.28] - 2023-08-16
106 - Ensure pool workers are properly initialized.
110 - HTTP server pool examples: express-cluster, express-hybrid.
114 - Remove now useless branching in worker hot code path.
116 ## [2.6.27] - 2023-08-15
120 - Add `KillHandler` type definition to exported types.
124 - Add `destroy` event to pool API.
126 ## [2.6.26] - 2023-08-15
130 - Add kill handler to worker options allowing to execute custom code when worker is killed.
131 - Add `listTaskFunctions()` method to pool API.
132 - SMTP server pool example: nodemailer.
134 ## [2.6.25] - 2023-08-13
138 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
139 - WebSocket server pool examples: ws-cluster, ws-hybrid.
141 ## [2.6.24] - 2023-08-12
145 - Add array of transferable objects to the `execute()` method arguments.
146 - WebSocket server pool examples: ws-worker_threads.
148 ## [2.6.23] - 2023-08-11
152 - 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.
156 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
157 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
159 ## [2.6.22] - 2023-08-10
163 - Add missing `types` field to package.json `exports`.
167 - Structure markdown documentation (PR #811).
169 ## [2.6.21] - 2023-08-03
173 - Improve code documentation.
174 - Code refactoring and cleanup for better maintainability and readability.
176 ## [2.6.20] - 2023-07-21
180 - Fix queued tasks redistribution on error task execution starvation.
181 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
185 - Drastically reduce lookups by worker in the worker nodes.
187 ## [2.6.19] - 2023-07-20
191 - Dedicated internal communication channel for worker_threads pools.
193 ## [2.6.18] - 2023-07-19
197 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
199 ## [2.6.17] - 2023-07-16
203 - Add `listTaskFunctions()` method to worker API.
205 ## [2.6.16] - 2023-07-12
209 - Fix pool startup detection.
210 - Fix worker task functions handling.
212 ## [2.6.15] - 2023-07-11
216 - Take into account worker node readiness in worker choice strategies.
218 ## [2.6.14] - 2023-07-10
222 - Fix task function statistics tracking.
224 ## [2.6.13] - 2023-07-10
228 - Add per task function statistics tracking.
229 - Add public methods to manipulate the worker task functions at runtime.
231 ## [2.6.12] - 2023-07-09
235 - Workaround import issue with `node:os` module in node 16.x.x.
237 ## [2.6.11] - 2023-07-09
241 - Fix pool readiness semantic.
243 ## [2.6.10] - 2023-07-08
247 - Ensure workers are not recreated on error at pool startup.
251 - Add `ready` and `strategy` fields to pool information.
252 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
253 - Add dynamic pool sizing checks.
255 ## [2.6.9] - 2023-07-07
259 - Recreate the right worker type on uncaught exception.
263 - Add minimum and maximum to internal measurement statistics.
264 - Add `runTime` and `waitTime` to pool information.
265 - Check worker inactive time only on dynamic worker.
267 ## [2.6.8] - 2023-07-03
271 - Brown paper bag release to fix version handling in pool information.
273 ## [2.6.7] - 2023-07-03
277 - Ensure worker queued tasks at error are reassigned to other pool workers.
281 - Add pool `utilization` ratio to pool information.
282 - Add `version` to pool information.
283 - Add worker information to worker nodes.
285 ## [2.6.6] - 2023-07-01
289 - Add safe helper `availableParallelism()` to help sizing the pool.
293 - Ensure message handler is only registered in worker.
295 ## [2.6.5] - 2023-06-27
299 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
303 - Artificial version bump to 2.6.5 to workaround publication issue.
304 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
305 - Ensure pool event is emitted before task error promise rejection.
306 - Fix queued tasks count computation.
310 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
312 ## [2.6.4] - 2023-06-27
316 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
320 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
321 - Ensure pool event is emitted before task error promise rejection.
322 - Fix queued tasks count computation.
326 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
328 ## [2.6.3] - 2023-06-19
332 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
333 - Update strategies internals after statistics computation.
337 - Optimize O(1) queue implementation.
339 ## [2.6.2] - 2023-06-12
343 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
345 ## [2.6.1] - 2023-06-10
349 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
353 - Fix average statistics computation: ensure failed tasks are not accounted.
355 ## [2.6.0] - 2023-06-09
359 - Add `LEAST_ELU` worker choice strategy (experimental).
360 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
364 - Refactor pool worker node usage internals.
365 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
366 - Breaking change: pool information `info` property object fields have been renamed.
370 - Fix wait time accounting.
371 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
372 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
374 ## [2.5.4] - 2023-06-07
378 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
382 - Compute statistics at the worker level only if needed.
383 - Add `worker_threads` options to thread pool options.
387 - Make the `LEAST_BUSY` strategy only relies on task runtime.
389 ## [2.5.3] - 2023-06-04
393 - Refine pool information content.
394 - Limit pool internals public exposure.
396 ## [2.5.2] - 2023-06-02
400 - Add `taskError` pool event for task execution error.
401 - Add pool information `info` property to pool.
402 - Emit pool information on `busy` and `full` pool events.
404 ## [2.5.1] - 2023-06-01
408 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
409 - Add `error` pool event for uncaught worker error.
411 ## [2.5.0] - 2023-05-31
415 - Switch pool event emitter to `EventEmitterAsyncResource`.
416 - Add tasks wait time accounting in per worker tasks usage.
417 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
421 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
423 ## [2.4.14] - 2023-05-09
427 - Ensure no undefined task runtime can land in the tasks history.
428 - Fix median computation implementation once again.
432 - Unit tests for median and queue implementations.
434 ## [2.4.13] - 2023-05-08
438 - Fix worker choice strategy options validation.
439 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
441 ## [2.4.12] - 2023-05-06
445 - Support multiple task functions per worker.
446 - Add custom worker weights support to worker choice strategies options.
450 - Use O(1) queue implementation for tasks queueing.
454 - Fix median computation implementation.
455 - Fix fair share worker choice strategy internals update.
457 ## [2.4.11] - 2023-04-23
461 - Optimize free worker finding in worker choice strategies.
463 ## [2.4.10] - 2023-04-15
467 - Fix typescript type definition for task function: ensure the input data is optional.
468 - Fix typescript type definition for pool execute(): ensure the input data is optional.
470 ## [2.4.9] - 2023-04-15
474 - Add tasks queue enablement runtime setter to pool.
475 - Add tasks queue options runtime setter to pool.
476 - Add worker choice strategy options runtime setter to pool.
480 - Remove the tasks queuing experimental status.
484 - Fix task function type definition and validation.
485 - Fix worker choice strategy options handling.
487 ## [2.4.8] - 2023-04-12
491 - Fix message between main worker and worker type definition for tasks.
492 - Fix code documentation.
494 ## [2.4.7] - 2023-04-11
498 - Add worker tasks queue options to pool options.
502 - Fix missing documentation.
504 ## [2.4.6] - 2023-04-10
508 - Ensure one task at a time is executed per worker with tasks queueing enabled.
509 - Properly count worker executing tasks with tasks queueing enabled.
511 ## [2.4.5] - 2023-04-09
515 - Use monotonic high resolution timer for worker tasks runtime.
516 - Add worker tasks median runtime to statistics.
517 - Add worker tasks queue (experimental).
519 ## [2.4.4] - 2023-04-07
523 - Add `PoolEvents` enumeration and `PoolEvent` type.
527 - Destroy worker only on alive check.
529 ## [2.4.3] - 2023-04-07
533 - Fix typedoc generation with inheritance.
535 ## [2.4.2] - 2023-04-06
539 - Add `full` event to dynamic pool.
540 - Keep worker choice strategy in memory for conditional reuse.
544 - Fix possible negative worker key at worker removal in worker choice strategies.
546 ## [2.4.1] - 2023-04-05
550 - Optimize worker choice strategy for dynamic pool.
554 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
556 ## [2.4.0] - 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.
569 - Optimize tasks usage statistics requirements for worker choice strategy.
573 - Ensure trimmable characters are checked at pool initialization.
574 - Fix message id integer overflow.
575 - Fix pool worker removal in worker choice strategy internals.
576 - Fix package publication with pnpm.
578 ## [2.4.0-3] - 2023-04-04
582 - Add `LESS_BUSY` worker choice strategy.
586 - Optimize worker storage in pool.
587 - Optimize worker alive status check.
588 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
589 - Optimize `LESS_USED` worker choice strategy.
590 - Update benchmarks versus external threads pools.
594 - Ensure trimmable characters are checked at pool initialization.
595 - Fix message id integer overflow.
596 - Fix pool worker removal in worker choice strategy internals.
597 - Fix package publication with pnpm.
599 ## [2.4.0-2] - 2023-04-03
603 - Add `LESS_BUSY` worker choice strategy.
607 - Optimize worker storage in pool.
608 - Optimize worker alive status check.
609 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
610 - Optimize `LESS_USED` worker choice strategy.
614 - Ensure trimmable characters are checked at pool initialization.
615 - Fix message id integer overflow.
616 - Fix pool worker removal in worker choice strategy internals.
617 - Fix package publication with pnpm.
619 ## [2.4.0-1] - 2023-04-03
623 - Add `LESS_BUSY` worker choice strategy.
627 - Optimize worker storage in pool.
628 - Optimize worker alive status check.
629 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
630 - Optimize `LESS_USED` worker choice strategy.
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.
638 ## [2.4.0-0] - 2023-04-03
642 - Add `LESS_BUSY` worker choice strategy.
646 - Optimize worker storage in pool.
647 - Optimize worker alive status check.
648 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
649 - Optimize `LESS_USED` worker choice strategy.
653 - Ensure trimmable characters are checked at pool initialization.
654 - Fix message id integer overflow.
655 - Fix pool worker removal in worker choice strategy internals.
657 ## [2.3.10] - 2023-03-18
661 - Fix package.json `exports` syntax for ESM and CommonJS.
665 - Permit SemVer pre-release publication.
667 ## [2.3.10-2] - 2023-03-18
671 - Fix package.json `exports` syntax for ESM and CommonJS.
673 ## [2.3.10-1] - 2023-03-18
677 - Permit SemVer pre-release publication.
679 ## [2.3.10-0] - 2023-03-18
683 - Fix package.json `exports` syntax for ESM and CommonJS.
685 ## [2.3.9] - 2023-03-18
689 - Introduce ESM module support along with CommonJS one.
693 - Fix brown paper bag bug referencing the same object literal.
695 ## [2.3.8] - 2023-03-18
699 - Switch internal benchmarking code to benny.
700 - Switch to TypeScript 5.x.x.
701 - Switch rollup bundler plugins to core ones.
702 - Switch to TSDoc syntax.
703 - Enforce conventional commits.
707 - Fix random integer generator.
708 - Fix worker choice strategy pool type identification at initialization.
710 ## [2.3.7] - 2022-10-23
714 - Switch to open collective FOSS project funding platform.
715 - Switch to ts-standard linter configuration on TypeScript code.
719 - Fixed missing async on pool execute method.
720 - Fixed typing in TypeScript example.
721 - Fixed types in unit tests.
723 ## [2.3.6] - 2022-10-22
727 - Cleanup pool attributes and methods.
728 - Refine error types thrown.
732 - Fix continuous integration build on windows.
733 - Fix code coverage reporting by using c8 instead of nyc.
735 ## [2.3.5] - 2022-10-21
739 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
740 - Optimize tasks usage lookup implementation.
744 - Fix missed pool event emitter type export.
745 - Fix typedoc documentation generation.
747 ## [2.3.4] - 2022-10-17
751 - Fully automate release process with release-it.
755 - Optimize fair share task scheduling algorithm implementation.
756 - Update benchmarks versus external pools results with latest version.
758 ## [2.3.3] - 2022-10-15
762 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
764 ## [2.3.2] - 2022-10-14
768 - Optimize fair share worker selection strategy implementation.
772 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
774 ## [2.3.1] - 2022-10-13
778 - Pool worker choice strategies:
779 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
780 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
782 ## [2.2.2] - 2022-10-09
786 - Fixed `README.md` file.
788 ## [2.2.1] - 2022-10-08
792 - Dynamic worker choice strategy change at runtime.
794 ## [2.2.0] - 2022-01-05
798 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
800 ## [2.1.0] - 2021-08-29
804 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
808 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
809 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
810 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
811 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
813 ## [2.0.2] - 2021-05-12
817 - Fix `busy` event emission on fixed pool type
819 ## [2.0.1] - 2021-03-16
823 - Check if pool options are properly set.
824 - `busy` event is emitted on all pool types.
826 ## [2.0.0] - 2021-03-01
830 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
834 - `FullPool` event is now renamed to `busy`.
835 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
836 _Find more details on our JSDoc._
838 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
840 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
842 ### Pool options types declaration merge
844 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
846 #### New `export` strategy
850 const DynamicThreadPool = require('poolifier/lib/dynamic')
852 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
855 But you should always prefer just using
858 const { DynamicThreadPool } = require('poolifier')
861 #### New type definitions for input data and response
863 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
864 _This is not a limitation by poolifier but Node.js._
866 #### Public property replacements
868 `numWorkers` property is now `numberOfWorkers`
870 #### Internal (protected) properties and methods renaming
872 These properties are not intended for end users
874 - `id` => `nextMessageId`
876 These methods are not intended for end users
878 - `_chooseWorker` => `chooseWorker`
879 - `_newWorker` => `createWorker`
880 - `_execute` => `internalExecute`
881 - `_chooseWorker` => `chooseWorker`
882 - `_checkAlive` => `checkAlive`
884 - `_runAsync` => `runAsync`
886 ## [1.1.0] - 2020-05-21
890 - ThreadWorker support async functions as option
891 - Various external library patches
893 ## [1.0.0] - 2020-01-24
897 - FixedThreadPool implementation
898 - DynamicThreadPool implementation
899 - WorkerThread implementation to improve developer experience