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 ## [2.6.39] - 2023-08-30
14 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized .
16 ## [2.6.38] - 2023-08-30
20 - Bundle typescript types declaration into one file.
24 - Improve interleaved weighted round robin worker choice strategy implementation.
26 ## [2.6.37] - 2023-08-28
30 - Ensure unused worker usage statistics are deleted at runtime.
34 - Rename worker choice strategy options `choiceRetries` to `retries`.
35 - Avoid unnecessary branching in worker choice strategies.
37 ## [2.6.36] - 2023-08-27
41 - Fix pool `execute()` arguments check.
45 - Make continuous tasks stealing algorithm less aggressive.
46 - Fine tune tasks stealing algorithm under back pressure.
48 ## [2.6.35] - 2023-08-25
52 - Don't account worker usage statistics for tasks that have failed.
53 - Fix pool information runtime and wait time median computation.
57 - Update simple moving average implementation to use a circular buffer.
58 - Update simple moving median implementation to use a circular buffer.
59 - Account for stolen tasks in worker usage statistics and pool information.
63 - Continuous tasks stealing algorithm.
65 ## [2.6.34] - 2023-08-24
69 - Avoid cascading tasks stealing under back pressure.
73 - Add fastpath to queued tasks rescheduling.
75 ## [2.6.33] - 2023-08-24
79 - Fix queued tasks rescheduling.
83 - Rename tasks queue options `queueMaxSize` to `size`.
87 - Task stealing scheduling algorithm if tasks queueing is enabled.
89 ## [2.6.32] - 2023-08-23
93 - Ensure no task can be executed when the pool is destroyed.
97 - Add `queueMaxSize` option to tasks queue options.
98 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
99 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
101 ## [2.6.31] - 2023-08-20
105 - Fix worker choice strategy retries mechanism in some edge cases.
109 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
110 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
112 ## [2.6.30] - 2023-08-19
116 - Ensure pool event `backPressure` is emitted.
117 - Ensure pool event `full` is emitted only once.
118 - Ensure worker node cannot be instantiated without proper arguments.
120 ## [2.6.29] - 2023-08-18
124 - Fix race condition between ready and task functions worker message handling at startup.
125 - Fix duplicate task function worker usage statistics computation per task function.
126 - Update task function worker usage statistics if and only if there's at least two different task functions.
127 - Fix race condition at task function worker usage executing task computation leading to negative value.
131 - 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).
132 - Use back pressure detection in worker choice strategies.
133 - Add worker choice strategies retries mechanism if no worker is eligible.
135 ## [2.6.28] - 2023-08-16
139 - Ensure pool workers are properly initialized.
143 - HTTP server pool examples: express-cluster, express-hybrid.
147 - Remove now useless branching in worker hot code path.
149 ## [2.6.27] - 2023-08-15
153 - Add `KillHandler` type definition to exported types.
157 - Add `destroy` event to pool API.
159 ## [2.6.26] - 2023-08-15
163 - Add kill handler to worker options allowing to execute custom code when worker is killed.
164 - Add `listTaskFunctions()` method to pool API.
165 - SMTP server pool example: nodemailer.
167 ## [2.6.25] - 2023-08-13
171 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
172 - WebSocket server pool examples: ws-cluster, ws-hybrid.
174 ## [2.6.24] - 2023-08-12
178 - Add array of transferable objects to the `execute()` method arguments.
179 - WebSocket server pool examples: ws-worker_threads.
181 ## [2.6.23] - 2023-08-11
185 - 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.
189 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
190 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
192 ## [2.6.22] - 2023-08-10
196 - Add missing `types` field to package.json `exports`.
200 - Structure markdown documentation (PR #811).
202 ## [2.6.21] - 2023-08-03
206 - Improve code documentation.
207 - Code refactoring and cleanup for better maintainability and readability.
209 ## [2.6.20] - 2023-07-21
213 - Fix queued tasks redistribution on error task execution starvation.
214 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
218 - Drastically reduce lookups by worker in the worker nodes.
220 ## [2.6.19] - 2023-07-20
224 - Dedicated internal communication channel for worker_threads pools.
226 ## [2.6.18] - 2023-07-19
230 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
232 ## [2.6.17] - 2023-07-16
236 - Add `listTaskFunctions()` method to worker API.
238 ## [2.6.16] - 2023-07-12
242 - Fix pool startup detection.
243 - Fix worker task functions handling.
245 ## [2.6.15] - 2023-07-11
249 - Take into account worker node readiness in worker choice strategies.
251 ## [2.6.14] - 2023-07-10
255 - Fix task function statistics tracking.
257 ## [2.6.13] - 2023-07-10
261 - Add per task function statistics tracking.
262 - Add public methods to manipulate the worker task functions at runtime.
264 ## [2.6.12] - 2023-07-09
268 - Workaround import issue with `node:os` module in node 16.x.x.
270 ## [2.6.11] - 2023-07-09
274 - Fix pool readiness semantic.
276 ## [2.6.10] - 2023-07-08
280 - Ensure workers are not recreated on error at pool startup.
284 - Add `ready` and `strategy` fields to pool information.
285 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
286 - Add dynamic pool sizing checks.
288 ## [2.6.9] - 2023-07-07
292 - Recreate the right worker type on uncaught exception.
296 - Add minimum and maximum to internal measurement statistics.
297 - Add `runTime` and `waitTime` to pool information.
298 - Check worker inactive time only on dynamic worker.
300 ## [2.6.8] - 2023-07-03
304 - Brown paper bag release to fix version handling in pool information.
306 ## [2.6.7] - 2023-07-03
310 - Ensure worker queued tasks at error are reassigned to other pool workers.
314 - Add pool `utilization` ratio to pool information.
315 - Add `version` to pool information.
316 - Add worker information to worker nodes.
318 ## [2.6.6] - 2023-07-01
322 - Add safe helper `availableParallelism()` to help sizing the pool.
326 - Ensure message handler is only registered in worker.
328 ## [2.6.5] - 2023-06-27
332 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
336 - Artificial version bump to 2.6.5 to workaround publication issue.
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 ## [2.6.4] - 2023-06-27
349 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
353 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
354 - Ensure pool event is emitted before task error promise rejection.
355 - Fix queued tasks count computation.
359 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
361 ## [2.6.3] - 2023-06-19
365 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
366 - Update strategies internals after statistics computation.
370 - Optimize O(1) queue implementation.
372 ## [2.6.2] - 2023-06-12
376 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
378 ## [2.6.1] - 2023-06-10
382 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
386 - Fix average statistics computation: ensure failed tasks are not accounted.
388 ## [2.6.0] - 2023-06-09
392 - Add `LEAST_ELU` worker choice strategy (experimental).
393 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
397 - Refactor pool worker node usage internals.
398 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
399 - Breaking change: pool information `info` property object fields have been renamed.
403 - Fix wait time accounting.
404 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
405 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
407 ## [2.5.4] - 2023-06-07
411 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
415 - Compute statistics at the worker level only if needed.
416 - Add `worker_threads` options to thread pool options.
420 - Make the `LEAST_BUSY` strategy only relies on task runtime.
422 ## [2.5.3] - 2023-06-04
426 - Refine pool information content.
427 - Limit pool internals public exposure.
429 ## [2.5.2] - 2023-06-02
433 - Add `taskError` pool event for task execution error.
434 - Add pool information `info` property to pool.
435 - Emit pool information on `busy` and `full` pool events.
437 ## [2.5.1] - 2023-06-01
441 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
442 - Add `error` pool event for uncaught worker error.
444 ## [2.5.0] - 2023-05-31
448 - Switch pool event emitter to `EventEmitterAsyncResource`.
449 - Add tasks wait time accounting in per worker tasks usage.
450 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
454 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
456 ## [2.4.14] - 2023-05-09
460 - Ensure no undefined task runtime can land in the tasks history.
461 - Fix median computation implementation once again.
465 - Unit tests for median and queue implementations.
467 ## [2.4.13] - 2023-05-08
471 - Fix worker choice strategy options validation.
472 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
474 ## [2.4.12] - 2023-05-06
478 - Support multiple task functions per worker.
479 - Add custom worker weights support to worker choice strategies options.
483 - Use O(1) queue implementation for tasks queueing.
487 - Fix median computation implementation.
488 - Fix fair share worker choice strategy internals update.
490 ## [2.4.11] - 2023-04-23
494 - Optimize free worker finding in worker choice strategies.
496 ## [2.4.10] - 2023-04-15
500 - Fix typescript type definition for task function: ensure the input data is optional.
501 - Fix typescript type definition for pool execute(): ensure the input data is optional.
503 ## [2.4.9] - 2023-04-15
507 - Add tasks queue enablement runtime setter to pool.
508 - Add tasks queue options runtime setter to pool.
509 - Add worker choice strategy options runtime setter to pool.
513 - Remove the tasks queuing experimental status.
517 - Fix task function type definition and validation.
518 - Fix worker choice strategy options handling.
520 ## [2.4.8] - 2023-04-12
524 - Fix message between main worker and worker type definition for tasks.
525 - Fix code documentation.
527 ## [2.4.7] - 2023-04-11
531 - Add worker tasks queue options to pool options.
535 - Fix missing documentation.
537 ## [2.4.6] - 2023-04-10
541 - Ensure one task at a time is executed per worker with tasks queueing enabled.
542 - Properly count worker executing tasks with tasks queueing enabled.
544 ## [2.4.5] - 2023-04-09
548 - Use monotonic high resolution timer for worker tasks runtime.
549 - Add worker tasks median runtime to statistics.
550 - Add worker tasks queue (experimental).
552 ## [2.4.4] - 2023-04-07
556 - Add `PoolEvents` enumeration and `PoolEvent` type.
560 - Destroy worker only on alive check.
562 ## [2.4.3] - 2023-04-07
566 - Fix typedoc generation with inheritance.
568 ## [2.4.2] - 2023-04-06
572 - Add `full` event to dynamic pool.
573 - Keep worker choice strategy in memory for conditional reuse.
577 - Fix possible negative worker key at worker removal in worker choice strategies.
579 ## [2.4.1] - 2023-04-05
583 - Optimize worker choice strategy for dynamic pool.
587 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
589 ## [2.4.0] - 2023-04-04
593 - Add `LESS_BUSY` worker choice strategy.
597 - Optimize worker storage in pool.
598 - Optimize worker alive status check.
599 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
600 - Optimize `LESS_USED` worker choice strategy.
601 - Update benchmarks versus external threads pools.
602 - Optimize tasks usage statistics requirements for worker choice strategy.
606 - Ensure trimmable characters are checked at pool initialization.
607 - Fix message id integer overflow.
608 - Fix pool worker removal in worker choice strategy internals.
609 - Fix package publication with pnpm.
611 ## [2.4.0-3] - 2023-04-04
615 - Add `LESS_BUSY` worker choice strategy.
619 - Optimize worker storage in pool.
620 - Optimize worker alive status check.
621 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
622 - Optimize `LESS_USED` worker choice strategy.
623 - Update benchmarks versus external threads pools.
627 - Ensure trimmable characters are checked at pool initialization.
628 - Fix message id integer overflow.
629 - Fix pool worker removal in worker choice strategy internals.
630 - Fix package publication with pnpm.
632 ## [2.4.0-2] - 2023-04-03
636 - Add `LESS_BUSY` worker choice strategy.
640 - Optimize worker storage in pool.
641 - Optimize worker alive status check.
642 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
643 - Optimize `LESS_USED` worker choice strategy.
647 - Ensure trimmable characters are checked at pool initialization.
648 - Fix message id integer overflow.
649 - Fix pool worker removal in worker choice strategy internals.
650 - Fix package publication with pnpm.
652 ## [2.4.0-1] - 2023-04-03
656 - Add `LESS_BUSY` worker choice strategy.
660 - Optimize worker storage in pool.
661 - Optimize worker alive status check.
662 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
663 - Optimize `LESS_USED` worker choice strategy.
667 - Ensure trimmable characters are checked at pool initialization.
668 - Fix message id integer overflow.
669 - Fix pool worker removal in worker choice strategy internals.
671 ## [2.4.0-0] - 2023-04-03
675 - Add `LESS_BUSY` worker choice strategy.
679 - Optimize worker storage in pool.
680 - Optimize worker alive status check.
681 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
682 - Optimize `LESS_USED` worker choice strategy.
686 - Ensure trimmable characters are checked at pool initialization.
687 - Fix message id integer overflow.
688 - Fix pool worker removal in worker choice strategy internals.
690 ## [2.3.10] - 2023-03-18
694 - Fix package.json `exports` syntax for ESM and CommonJS.
698 - Permit SemVer pre-release publication.
700 ## [2.3.10-2] - 2023-03-18
704 - Fix package.json `exports` syntax for ESM and CommonJS.
706 ## [2.3.10-1] - 2023-03-18
710 - Permit SemVer pre-release publication.
712 ## [2.3.10-0] - 2023-03-18
716 - Fix package.json `exports` syntax for ESM and CommonJS.
718 ## [2.3.9] - 2023-03-18
722 - Introduce ESM module support along with CommonJS one.
726 - Fix brown paper bag bug referencing the same object literal.
728 ## [2.3.8] - 2023-03-18
732 - Switch internal benchmarking code to benny.
733 - Switch to TypeScript 5.x.x.
734 - Switch rollup bundler plugins to core ones.
735 - Switch to TSDoc syntax.
736 - Enforce conventional commits.
740 - Fix random integer generator.
741 - Fix worker choice strategy pool type identification at initialization.
743 ## [2.3.7] - 2022-10-23
747 - Switch to open collective FOSS project funding platform.
748 - Switch to ts-standard linter configuration on TypeScript code.
752 - Fixed missing async on pool execute method.
753 - Fixed typing in TypeScript example.
754 - Fixed types in unit tests.
756 ## [2.3.6] - 2022-10-22
760 - Cleanup pool attributes and methods.
761 - Refine error types thrown.
765 - Fix continuous integration build on windows.
766 - Fix code coverage reporting by using c8 instead of nyc.
768 ## [2.3.5] - 2022-10-21
772 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
773 - Optimize tasks usage lookup implementation.
777 - Fix missed pool event emitter type export.
778 - Fix typedoc documentation generation.
780 ## [2.3.4] - 2022-10-17
784 - Fully automate release process with release-it.
788 - Optimize fair share task scheduling algorithm implementation.
789 - Update benchmarks versus external pools results with latest version.
791 ## [2.3.3] - 2022-10-15
795 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
797 ## [2.3.2] - 2022-10-14
801 - Optimize fair share worker selection strategy implementation.
805 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
807 ## [2.3.1] - 2022-10-13
811 - Pool worker choice strategies:
812 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
813 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
815 ## [2.2.2] - 2022-10-09
819 - Fixed `README.md` file.
821 ## [2.2.1] - 2022-10-08
825 - Dynamic worker choice strategy change at runtime.
827 ## [2.2.0] - 2022-01-05
831 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
833 ## [2.1.0] - 2021-08-29
837 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
841 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
842 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
843 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
844 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
846 ## [2.0.2] - 2021-05-12
850 - Fix `busy` event emission on fixed pool type
852 ## [2.0.1] - 2021-03-16
856 - Check if pool options are properly set.
857 - `busy` event is emitted on all pool types.
859 ## [2.0.0] - 2021-03-01
863 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
867 - `FullPool` event is now renamed to `busy`.
868 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
869 _Find more details on our JSDoc._
871 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
873 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
875 ### Pool options types declaration merge
877 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
879 #### New `export` strategy
883 const DynamicThreadPool = require('poolifier/lib/dynamic')
885 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
888 But you should always prefer just using
891 const { DynamicThreadPool } = require('poolifier')
894 #### New type definitions for input data and response
896 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
897 _This is not a limitation by poolifier but Node.js._
899 #### Public property replacements
901 `numWorkers` property is now `numberOfWorkers`
903 #### Internal (protected) properties and methods renaming
905 These properties are not intended for end users
907 - `id` => `nextMessageId`
909 These methods are not intended for end users
911 - `_chooseWorker` => `chooseWorker`
912 - `_newWorker` => `createWorker`
913 - `_execute` => `internalExecute`
914 - `_chooseWorker` => `chooseWorker`
915 - `_checkAlive` => `checkAlive`
917 - `_runAsync` => `runAsync`
919 ## [1.1.0] - 2020-05-21
923 - ThreadWorker support async functions as option
924 - Various external library patches
926 ## [1.0.0] - 2020-01-24
930 - FixedThreadPool implementation
931 - DynamicThreadPool implementation
932 - WorkerThread implementation to improve developer experience