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 ## [2.6.37] - 2023-08-28
14 - Ensure unused worker usage statistics are deleted at runtime.
18 - Rename worker choice strategy options `choiceRetries` to `retries`.
19 - Avoid unnecessary branching in worker choice strategies.
21 ## [2.6.36] - 2023-08-27
25 - Fix pool `execute()` arguments check.
29 - Make continuous tasks stealing algorithm less aggressive.
30 - Fine tune tasks stealing algorithm under back pressure.
32 ## [2.6.35] - 2023-08-25
36 - Don't account worker usage statistics for tasks that have failed.
37 - Fix pool information runtime and wait time median computation.
41 - Update simple moving average implementation to use a circular buffer.
42 - Update simple moving median implementation to use a circular buffer.
43 - Account for stolen tasks in worker usage statistics and pool information.
47 - Continuous tasks stealing algorithm.
49 ## [2.6.34] - 2023-08-24
53 - Avoid cascading tasks stealing under back pressure.
57 - Add fastpath to queued tasks rescheduling.
59 ## [2.6.33] - 2023-08-24
63 - Fix queued tasks rescheduling.
67 - Rename tasks queue options `queueMaxSize` to `size`.
71 - Task stealing scheduling algorithm if tasks queueing is enabled.
73 ## [2.6.32] - 2023-08-23
77 - Ensure no task can be executed when the pool is destroyed.
81 - Add `queueMaxSize` option to tasks queue options.
82 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
83 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
85 ## [2.6.31] - 2023-08-20
89 - Fix worker choice strategy retries mechanism in some edge cases.
93 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
94 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
96 ## [2.6.30] - 2023-08-19
100 - Ensure pool event `backPressure` is emitted.
101 - Ensure pool event `full` is emitted only once.
102 - Ensure worker node cannot be instantiated without proper arguments.
104 ## [2.6.29] - 2023-08-18
108 - Fix race condition between ready and task functions worker message handling at startup.
109 - Fix duplicate task function worker usage statistics computation per task function.
110 - Update task function worker usage statistics if and only if there's at least two different task functions.
111 - Fix race condition at task function worker usage executing task computation leading to negative value.
115 - 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).
116 - Use back pressure detection in worker choice strategies.
117 - Add worker choice strategies retries mechanism if no worker is eligible.
119 ## [2.6.28] - 2023-08-16
123 - Ensure pool workers are properly initialized.
127 - HTTP server pool examples: express-cluster, express-hybrid.
131 - Remove now useless branching in worker hot code path.
133 ## [2.6.27] - 2023-08-15
137 - Add `KillHandler` type definition to exported types.
141 - Add `destroy` event to pool API.
143 ## [2.6.26] - 2023-08-15
147 - Add kill handler to worker options allowing to execute custom code when worker is killed.
148 - Add `listTaskFunctions()` method to pool API.
149 - SMTP server pool example: nodemailer.
151 ## [2.6.25] - 2023-08-13
155 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
156 - WebSocket server pool examples: ws-cluster, ws-hybrid.
158 ## [2.6.24] - 2023-08-12
162 - Add array of transferable objects to the `execute()` method arguments.
163 - WebSocket server pool examples: ws-worker_threads.
165 ## [2.6.23] - 2023-08-11
169 - 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.
173 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
174 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
176 ## [2.6.22] - 2023-08-10
180 - Add missing `types` field to package.json `exports`.
184 - Structure markdown documentation (PR #811).
186 ## [2.6.21] - 2023-08-03
190 - Improve code documentation.
191 - Code refactoring and cleanup for better maintainability and readability.
193 ## [2.6.20] - 2023-07-21
197 - Fix queued tasks redistribution on error task execution starvation.
198 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
202 - Drastically reduce lookups by worker in the worker nodes.
204 ## [2.6.19] - 2023-07-20
208 - Dedicated internal communication channel for worker_threads pools.
210 ## [2.6.18] - 2023-07-19
214 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
216 ## [2.6.17] - 2023-07-16
220 - Add `listTaskFunctions()` method to worker API.
222 ## [2.6.16] - 2023-07-12
226 - Fix pool startup detection.
227 - Fix worker task functions handling.
229 ## [2.6.15] - 2023-07-11
233 - Take into account worker node readiness in worker choice strategies.
235 ## [2.6.14] - 2023-07-10
239 - Fix task function statistics tracking.
241 ## [2.6.13] - 2023-07-10
245 - Add per task function statistics tracking.
246 - Add public methods to manipulate the worker task functions at runtime.
248 ## [2.6.12] - 2023-07-09
252 - Workaround import issue with `node:os` module in node 16.x.x.
254 ## [2.6.11] - 2023-07-09
258 - Fix pool readiness semantic.
260 ## [2.6.10] - 2023-07-08
264 - Ensure workers are not recreated on error at pool startup.
268 - Add `ready` and `strategy` fields to pool information.
269 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
270 - Add dynamic pool sizing checks.
272 ## [2.6.9] - 2023-07-07
276 - Recreate the right worker type on uncaught exception.
280 - Add minimum and maximum to internal measurement statistics.
281 - Add `runTime` and `waitTime` to pool information.
282 - Check worker inactive time only on dynamic worker.
284 ## [2.6.8] - 2023-07-03
288 - Brown paper bag release to fix version handling in pool information.
290 ## [2.6.7] - 2023-07-03
294 - Ensure worker queued tasks at error are reassigned to other pool workers.
298 - Add pool `utilization` ratio to pool information.
299 - Add `version` to pool information.
300 - Add worker information to worker nodes.
302 ## [2.6.6] - 2023-07-01
306 - Add safe helper `availableParallelism()` to help sizing the pool.
310 - Ensure message handler is only registered in worker.
312 ## [2.6.5] - 2023-06-27
316 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
320 - Artificial version bump to 2.6.5 to workaround publication issue.
321 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
322 - Ensure pool event is emitted before task error promise rejection.
323 - Fix queued tasks count computation.
327 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
329 ## [2.6.4] - 2023-06-27
333 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
337 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
338 - Ensure pool event is emitted before task error promise rejection.
339 - Fix queued tasks count computation.
343 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
345 ## [2.6.3] - 2023-06-19
349 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
350 - Update strategies internals after statistics computation.
354 - Optimize O(1) queue implementation.
356 ## [2.6.2] - 2023-06-12
360 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
362 ## [2.6.1] - 2023-06-10
366 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
370 - Fix average statistics computation: ensure failed tasks are not accounted.
372 ## [2.6.0] - 2023-06-09
376 - Add `LEAST_ELU` worker choice strategy (experimental).
377 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
381 - Refactor pool worker node usage internals.
382 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
383 - Breaking change: pool information `info` property object fields have been renamed.
387 - Fix wait time accounting.
388 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
389 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
391 ## [2.5.4] - 2023-06-07
395 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
399 - Compute statistics at the worker level only if needed.
400 - Add `worker_threads` options to thread pool options.
404 - Make the `LEAST_BUSY` strategy only relies on task runtime.
406 ## [2.5.3] - 2023-06-04
410 - Refine pool information content.
411 - Limit pool internals public exposure.
413 ## [2.5.2] - 2023-06-02
417 - Add `taskError` pool event for task execution error.
418 - Add pool information `info` property to pool.
419 - Emit pool information on `busy` and `full` pool events.
421 ## [2.5.1] - 2023-06-01
425 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
426 - Add `error` pool event for uncaught worker error.
428 ## [2.5.0] - 2023-05-31
432 - Switch pool event emitter to `EventEmitterAsyncResource`.
433 - Add tasks wait time accounting in per worker tasks usage.
434 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
438 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
440 ## [2.4.14] - 2023-05-09
444 - Ensure no undefined task runtime can land in the tasks history.
445 - Fix median computation implementation once again.
449 - Unit tests for median and queue implementations.
451 ## [2.4.13] - 2023-05-08
455 - Fix worker choice strategy options validation.
456 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
458 ## [2.4.12] - 2023-05-06
462 - Support multiple task functions per worker.
463 - Add custom worker weights support to worker choice strategies options.
467 - Use O(1) queue implementation for tasks queueing.
471 - Fix median computation implementation.
472 - Fix fair share worker choice strategy internals update.
474 ## [2.4.11] - 2023-04-23
478 - Optimize free worker finding in worker choice strategies.
480 ## [2.4.10] - 2023-04-15
484 - Fix typescript type definition for task function: ensure the input data is optional.
485 - Fix typescript type definition for pool execute(): ensure the input data is optional.
487 ## [2.4.9] - 2023-04-15
491 - Add tasks queue enablement runtime setter to pool.
492 - Add tasks queue options runtime setter to pool.
493 - Add worker choice strategy options runtime setter to pool.
497 - Remove the tasks queuing experimental status.
501 - Fix task function type definition and validation.
502 - Fix worker choice strategy options handling.
504 ## [2.4.8] - 2023-04-12
508 - Fix message between main worker and worker type definition for tasks.
509 - Fix code documentation.
511 ## [2.4.7] - 2023-04-11
515 - Add worker tasks queue options to pool options.
519 - Fix missing documentation.
521 ## [2.4.6] - 2023-04-10
525 - Ensure one task at a time is executed per worker with tasks queueing enabled.
526 - Properly count worker executing tasks with tasks queueing enabled.
528 ## [2.4.5] - 2023-04-09
532 - Use monotonic high resolution timer for worker tasks runtime.
533 - Add worker tasks median runtime to statistics.
534 - Add worker tasks queue (experimental).
536 ## [2.4.4] - 2023-04-07
540 - Add `PoolEvents` enumeration and `PoolEvent` type.
544 - Destroy worker only on alive check.
546 ## [2.4.3] - 2023-04-07
550 - Fix typedoc generation with inheritance.
552 ## [2.4.2] - 2023-04-06
556 - Add `full` event to dynamic pool.
557 - Keep worker choice strategy in memory for conditional reuse.
561 - Fix possible negative worker key at worker removal in worker choice strategies.
563 ## [2.4.1] - 2023-04-05
567 - Optimize worker choice strategy for dynamic pool.
571 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
573 ## [2.4.0] - 2023-04-04
577 - Add `LESS_BUSY` worker choice strategy.
581 - Optimize worker storage in pool.
582 - Optimize worker alive status check.
583 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
584 - Optimize `LESS_USED` worker choice strategy.
585 - Update benchmarks versus external threads pools.
586 - Optimize tasks usage statistics requirements for worker choice strategy.
590 - Ensure trimmable characters are checked at pool initialization.
591 - Fix message id integer overflow.
592 - Fix pool worker removal in worker choice strategy internals.
593 - Fix package publication with pnpm.
595 ## [2.4.0-3] - 2023-04-04
599 - Add `LESS_BUSY` worker choice strategy.
603 - Optimize worker storage in pool.
604 - Optimize worker alive status check.
605 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
606 - Optimize `LESS_USED` worker choice strategy.
607 - Update benchmarks versus external threads pools.
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 ## [2.4.0-2] - 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.
634 - Fix package publication with pnpm.
636 ## [2.4.0-1] - 2023-04-03
640 - Add `LESS_BUSY` worker choice strategy.
644 - Optimize worker storage in pool.
645 - Optimize worker alive status check.
646 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
647 - Optimize `LESS_USED` worker choice strategy.
651 - Ensure trimmable characters are checked at pool initialization.
652 - Fix message id integer overflow.
653 - Fix pool worker removal in worker choice strategy internals.
655 ## [2.4.0-0] - 2023-04-03
659 - Add `LESS_BUSY` worker choice strategy.
663 - Optimize worker storage in pool.
664 - Optimize worker alive status check.
665 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
666 - Optimize `LESS_USED` worker choice strategy.
670 - Ensure trimmable characters are checked at pool initialization.
671 - Fix message id integer overflow.
672 - Fix pool worker removal in worker choice strategy internals.
674 ## [2.3.10] - 2023-03-18
678 - Fix package.json `exports` syntax for ESM and CommonJS.
682 - Permit SemVer pre-release publication.
684 ## [2.3.10-2] - 2023-03-18
688 - Fix package.json `exports` syntax for ESM and CommonJS.
690 ## [2.3.10-1] - 2023-03-18
694 - Permit SemVer pre-release publication.
696 ## [2.3.10-0] - 2023-03-18
700 - Fix package.json `exports` syntax for ESM and CommonJS.
702 ## [2.3.9] - 2023-03-18
706 - Introduce ESM module support along with CommonJS one.
710 - Fix brown paper bag bug referencing the same object literal.
712 ## [2.3.8] - 2023-03-18
716 - Switch internal benchmarking code to benny.
717 - Switch to TypeScript 5.x.x.
718 - Switch rollup bundler plugins to core ones.
719 - Switch to TSDoc syntax.
720 - Enforce conventional commits.
724 - Fix random integer generator.
725 - Fix worker choice strategy pool type identification at initialization.
727 ## [2.3.7] - 2022-10-23
731 - Switch to open collective FOSS project funding platform.
732 - Switch to ts-standard linter configuration on TypeScript code.
736 - Fixed missing async on pool execute method.
737 - Fixed typing in TypeScript example.
738 - Fixed types in unit tests.
740 ## [2.3.6] - 2022-10-22
744 - Cleanup pool attributes and methods.
745 - Refine error types thrown.
749 - Fix continuous integration build on windows.
750 - Fix code coverage reporting by using c8 instead of nyc.
752 ## [2.3.5] - 2022-10-21
756 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
757 - Optimize tasks usage lookup implementation.
761 - Fix missed pool event emitter type export.
762 - Fix typedoc documentation generation.
764 ## [2.3.4] - 2022-10-17
768 - Fully automate release process with release-it.
772 - Optimize fair share task scheduling algorithm implementation.
773 - Update benchmarks versus external pools results with latest version.
775 ## [2.3.3] - 2022-10-15
779 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
781 ## [2.3.2] - 2022-10-14
785 - Optimize fair share worker selection strategy implementation.
789 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
791 ## [2.3.1] - 2022-10-13
795 - Pool worker choice strategies:
796 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
797 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
799 ## [2.2.2] - 2022-10-09
803 - Fixed `README.md` file.
805 ## [2.2.1] - 2022-10-08
809 - Dynamic worker choice strategy change at runtime.
811 ## [2.2.0] - 2022-01-05
815 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
817 ## [2.1.0] - 2021-08-29
821 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
825 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
826 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
827 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
828 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
830 ## [2.0.2] - 2021-05-12
834 - Fix `busy` event emission on fixed pool type
836 ## [2.0.1] - 2021-03-16
840 - Check if pool options are properly set.
841 - `busy` event is emitted on all pool types.
843 ## [2.0.0] - 2021-03-01
847 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
851 - `FullPool` event is now renamed to `busy`.
852 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
853 _Find more details on our JSDoc._
855 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
857 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
859 ### Pool options types declaration merge
861 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
863 #### New `export` strategy
867 const DynamicThreadPool = require('poolifier/lib/dynamic')
869 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
872 But you should always prefer just using
875 const { DynamicThreadPool } = require('poolifier')
878 #### New type definitions for input data and response
880 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
881 _This is not a limitation by poolifier but Node.js._
883 #### Public property replacements
885 `numWorkers` property is now `numberOfWorkers`
887 #### Internal (protected) properties and methods renaming
889 These properties are not intended for end users
891 - `id` => `nextMessageId`
893 These methods are not intended for end users
895 - `_chooseWorker` => `chooseWorker`
896 - `_newWorker` => `createWorker`
897 - `_execute` => `internalExecute`
898 - `_chooseWorker` => `chooseWorker`
899 - `_checkAlive` => `checkAlive`
901 - `_runAsync` => `runAsync`
903 ## [1.1.0] - 2020-05-21
907 - ThreadWorker support async functions as option
908 - Various external library patches
910 ## [1.0.0] - 2020-01-24
914 - FixedThreadPool implementation
915 - DynamicThreadPool implementation
916 - WorkerThread implementation to improve developer experience