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 - Bundle typescript types declaration into one file.
16 - Improve interleaved weighted round robin worker choice strategy implementation.
18 ## [2.6.37] - 2023-08-28
22 - Ensure unused worker usage statistics are deleted at runtime.
26 - Rename worker choice strategy options `choiceRetries` to `retries`.
27 - Avoid unnecessary branching in worker choice strategies.
29 ## [2.6.36] - 2023-08-27
33 - Fix pool `execute()` arguments check.
37 - Make continuous tasks stealing algorithm less aggressive.
38 - Fine tune tasks stealing algorithm under back pressure.
40 ## [2.6.35] - 2023-08-25
44 - Don't account worker usage statistics for tasks that have failed.
45 - Fix pool information runtime and wait time median computation.
49 - Update simple moving average implementation to use a circular buffer.
50 - Update simple moving median implementation to use a circular buffer.
51 - Account for stolen tasks in worker usage statistics and pool information.
55 - Continuous tasks stealing algorithm.
57 ## [2.6.34] - 2023-08-24
61 - Avoid cascading tasks stealing under back pressure.
65 - Add fastpath to queued tasks rescheduling.
67 ## [2.6.33] - 2023-08-24
71 - Fix queued tasks rescheduling.
75 - Rename tasks queue options `queueMaxSize` to `size`.
79 - Task stealing scheduling algorithm if tasks queueing is enabled.
81 ## [2.6.32] - 2023-08-23
85 - Ensure no task can be executed when the pool is destroyed.
89 - Add `queueMaxSize` option to tasks queue options.
90 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
91 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
93 ## [2.6.31] - 2023-08-20
97 - Fix worker choice strategy retries mechanism in some edge cases.
101 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
102 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
104 ## [2.6.30] - 2023-08-19
108 - Ensure pool event `backPressure` is emitted.
109 - Ensure pool event `full` is emitted only once.
110 - Ensure worker node cannot be instantiated without proper arguments.
112 ## [2.6.29] - 2023-08-18
116 - Fix race condition between ready and task functions worker message handling at startup.
117 - Fix duplicate task function worker usage statistics computation per task function.
118 - Update task function worker usage statistics if and only if there's at least two different task functions.
119 - Fix race condition at task function worker usage executing task computation leading to negative value.
123 - 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).
124 - Use back pressure detection in worker choice strategies.
125 - Add worker choice strategies retries mechanism if no worker is eligible.
127 ## [2.6.28] - 2023-08-16
131 - Ensure pool workers are properly initialized.
135 - HTTP server pool examples: express-cluster, express-hybrid.
139 - Remove now useless branching in worker hot code path.
141 ## [2.6.27] - 2023-08-15
145 - Add `KillHandler` type definition to exported types.
149 - Add `destroy` event to pool API.
151 ## [2.6.26] - 2023-08-15
155 - Add kill handler to worker options allowing to execute custom code when worker is killed.
156 - Add `listTaskFunctions()` method to pool API.
157 - SMTP server pool example: nodemailer.
159 ## [2.6.25] - 2023-08-13
163 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
164 - WebSocket server pool examples: ws-cluster, ws-hybrid.
166 ## [2.6.24] - 2023-08-12
170 - Add array of transferable objects to the `execute()` method arguments.
171 - WebSocket server pool examples: ws-worker_threads.
173 ## [2.6.23] - 2023-08-11
177 - 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.
181 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
182 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
184 ## [2.6.22] - 2023-08-10
188 - Add missing `types` field to package.json `exports`.
192 - Structure markdown documentation (PR #811).
194 ## [2.6.21] - 2023-08-03
198 - Improve code documentation.
199 - Code refactoring and cleanup for better maintainability and readability.
201 ## [2.6.20] - 2023-07-21
205 - Fix queued tasks redistribution on error task execution starvation.
206 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
210 - Drastically reduce lookups by worker in the worker nodes.
212 ## [2.6.19] - 2023-07-20
216 - Dedicated internal communication channel for worker_threads pools.
218 ## [2.6.18] - 2023-07-19
222 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
224 ## [2.6.17] - 2023-07-16
228 - Add `listTaskFunctions()` method to worker API.
230 ## [2.6.16] - 2023-07-12
234 - Fix pool startup detection.
235 - Fix worker task functions handling.
237 ## [2.6.15] - 2023-07-11
241 - Take into account worker node readiness in worker choice strategies.
243 ## [2.6.14] - 2023-07-10
247 - Fix task function statistics tracking.
249 ## [2.6.13] - 2023-07-10
253 - Add per task function statistics tracking.
254 - Add public methods to manipulate the worker task functions at runtime.
256 ## [2.6.12] - 2023-07-09
260 - Workaround import issue with `node:os` module in node 16.x.x.
262 ## [2.6.11] - 2023-07-09
266 - Fix pool readiness semantic.
268 ## [2.6.10] - 2023-07-08
272 - Ensure workers are not recreated on error at pool startup.
276 - Add `ready` and `strategy` fields to pool information.
277 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
278 - Add dynamic pool sizing checks.
280 ## [2.6.9] - 2023-07-07
284 - Recreate the right worker type on uncaught exception.
288 - Add minimum and maximum to internal measurement statistics.
289 - Add `runTime` and `waitTime` to pool information.
290 - Check worker inactive time only on dynamic worker.
292 ## [2.6.8] - 2023-07-03
296 - Brown paper bag release to fix version handling in pool information.
298 ## [2.6.7] - 2023-07-03
302 - Ensure worker queued tasks at error are reassigned to other pool workers.
306 - Add pool `utilization` ratio to pool information.
307 - Add `version` to pool information.
308 - Add worker information to worker nodes.
310 ## [2.6.6] - 2023-07-01
314 - Add safe helper `availableParallelism()` to help sizing the pool.
318 - Ensure message handler is only registered in worker.
320 ## [2.6.5] - 2023-06-27
324 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
328 - Artificial version bump to 2.6.5 to workaround publication issue.
329 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
330 - Ensure pool event is emitted before task error promise rejection.
331 - Fix queued tasks count computation.
335 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
337 ## [2.6.4] - 2023-06-27
341 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
345 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
346 - Ensure pool event is emitted before task error promise rejection.
347 - Fix queued tasks count computation.
351 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
353 ## [2.6.3] - 2023-06-19
357 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
358 - Update strategies internals after statistics computation.
362 - Optimize O(1) queue implementation.
364 ## [2.6.2] - 2023-06-12
368 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
370 ## [2.6.1] - 2023-06-10
374 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
378 - Fix average statistics computation: ensure failed tasks are not accounted.
380 ## [2.6.0] - 2023-06-09
384 - Add `LEAST_ELU` worker choice strategy (experimental).
385 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
389 - Refactor pool worker node usage internals.
390 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
391 - Breaking change: pool information `info` property object fields have been renamed.
395 - Fix wait time accounting.
396 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
397 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
399 ## [2.5.4] - 2023-06-07
403 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
407 - Compute statistics at the worker level only if needed.
408 - Add `worker_threads` options to thread pool options.
412 - Make the `LEAST_BUSY` strategy only relies on task runtime.
414 ## [2.5.3] - 2023-06-04
418 - Refine pool information content.
419 - Limit pool internals public exposure.
421 ## [2.5.2] - 2023-06-02
425 - Add `taskError` pool event for task execution error.
426 - Add pool information `info` property to pool.
427 - Emit pool information on `busy` and `full` pool events.
429 ## [2.5.1] - 2023-06-01
433 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
434 - Add `error` pool event for uncaught worker error.
436 ## [2.5.0] - 2023-05-31
440 - Switch pool event emitter to `EventEmitterAsyncResource`.
441 - Add tasks wait time accounting in per worker tasks usage.
442 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
446 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
448 ## [2.4.14] - 2023-05-09
452 - Ensure no undefined task runtime can land in the tasks history.
453 - Fix median computation implementation once again.
457 - Unit tests for median and queue implementations.
459 ## [2.4.13] - 2023-05-08
463 - Fix worker choice strategy options validation.
464 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
466 ## [2.4.12] - 2023-05-06
470 - Support multiple task functions per worker.
471 - Add custom worker weights support to worker choice strategies options.
475 - Use O(1) queue implementation for tasks queueing.
479 - Fix median computation implementation.
480 - Fix fair share worker choice strategy internals update.
482 ## [2.4.11] - 2023-04-23
486 - Optimize free worker finding in worker choice strategies.
488 ## [2.4.10] - 2023-04-15
492 - Fix typescript type definition for task function: ensure the input data is optional.
493 - Fix typescript type definition for pool execute(): ensure the input data is optional.
495 ## [2.4.9] - 2023-04-15
499 - Add tasks queue enablement runtime setter to pool.
500 - Add tasks queue options runtime setter to pool.
501 - Add worker choice strategy options runtime setter to pool.
505 - Remove the tasks queuing experimental status.
509 - Fix task function type definition and validation.
510 - Fix worker choice strategy options handling.
512 ## [2.4.8] - 2023-04-12
516 - Fix message between main worker and worker type definition for tasks.
517 - Fix code documentation.
519 ## [2.4.7] - 2023-04-11
523 - Add worker tasks queue options to pool options.
527 - Fix missing documentation.
529 ## [2.4.6] - 2023-04-10
533 - Ensure one task at a time is executed per worker with tasks queueing enabled.
534 - Properly count worker executing tasks with tasks queueing enabled.
536 ## [2.4.5] - 2023-04-09
540 - Use monotonic high resolution timer for worker tasks runtime.
541 - Add worker tasks median runtime to statistics.
542 - Add worker tasks queue (experimental).
544 ## [2.4.4] - 2023-04-07
548 - Add `PoolEvents` enumeration and `PoolEvent` type.
552 - Destroy worker only on alive check.
554 ## [2.4.3] - 2023-04-07
558 - Fix typedoc generation with inheritance.
560 ## [2.4.2] - 2023-04-06
564 - Add `full` event to dynamic pool.
565 - Keep worker choice strategy in memory for conditional reuse.
569 - Fix possible negative worker key at worker removal in worker choice strategies.
571 ## [2.4.1] - 2023-04-05
575 - Optimize worker choice strategy for dynamic pool.
579 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
581 ## [2.4.0] - 2023-04-04
585 - Add `LESS_BUSY` worker choice strategy.
589 - Optimize worker storage in pool.
590 - Optimize worker alive status check.
591 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
592 - Optimize `LESS_USED` worker choice strategy.
593 - Update benchmarks versus external threads pools.
594 - Optimize tasks usage statistics requirements for worker choice strategy.
598 - Ensure trimmable characters are checked at pool initialization.
599 - Fix message id integer overflow.
600 - Fix pool worker removal in worker choice strategy internals.
601 - Fix package publication with pnpm.
603 ## [2.4.0-3] - 2023-04-04
607 - Add `LESS_BUSY` worker choice strategy.
611 - Optimize worker storage in pool.
612 - Optimize worker alive status check.
613 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
614 - Optimize `LESS_USED` worker choice strategy.
615 - Update benchmarks versus external threads pools.
619 - Ensure trimmable characters are checked at pool initialization.
620 - Fix message id integer overflow.
621 - Fix pool worker removal in worker choice strategy internals.
622 - Fix package publication with pnpm.
624 ## [2.4.0-2] - 2023-04-03
628 - Add `LESS_BUSY` worker choice strategy.
632 - Optimize worker storage in pool.
633 - Optimize worker alive status check.
634 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
635 - Optimize `LESS_USED` worker choice strategy.
639 - Ensure trimmable characters are checked at pool initialization.
640 - Fix message id integer overflow.
641 - Fix pool worker removal in worker choice strategy internals.
642 - Fix package publication with pnpm.
644 ## [2.4.0-1] - 2023-04-03
648 - Add `LESS_BUSY` worker choice strategy.
652 - Optimize worker storage in pool.
653 - Optimize worker alive status check.
654 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
655 - Optimize `LESS_USED` worker choice strategy.
659 - Ensure trimmable characters are checked at pool initialization.
660 - Fix message id integer overflow.
661 - Fix pool worker removal in worker choice strategy internals.
663 ## [2.4.0-0] - 2023-04-03
667 - Add `LESS_BUSY` worker choice strategy.
671 - Optimize worker storage in pool.
672 - Optimize worker alive status check.
673 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
674 - Optimize `LESS_USED` worker choice strategy.
678 - Ensure trimmable characters are checked at pool initialization.
679 - Fix message id integer overflow.
680 - Fix pool worker removal in worker choice strategy internals.
682 ## [2.3.10] - 2023-03-18
686 - Fix package.json `exports` syntax for ESM and CommonJS.
690 - Permit SemVer pre-release publication.
692 ## [2.3.10-2] - 2023-03-18
696 - Fix package.json `exports` syntax for ESM and CommonJS.
698 ## [2.3.10-1] - 2023-03-18
702 - Permit SemVer pre-release publication.
704 ## [2.3.10-0] - 2023-03-18
708 - Fix package.json `exports` syntax for ESM and CommonJS.
710 ## [2.3.9] - 2023-03-18
714 - Introduce ESM module support along with CommonJS one.
718 - Fix brown paper bag bug referencing the same object literal.
720 ## [2.3.8] - 2023-03-18
724 - Switch internal benchmarking code to benny.
725 - Switch to TypeScript 5.x.x.
726 - Switch rollup bundler plugins to core ones.
727 - Switch to TSDoc syntax.
728 - Enforce conventional commits.
732 - Fix random integer generator.
733 - Fix worker choice strategy pool type identification at initialization.
735 ## [2.3.7] - 2022-10-23
739 - Switch to open collective FOSS project funding platform.
740 - Switch to ts-standard linter configuration on TypeScript code.
744 - Fixed missing async on pool execute method.
745 - Fixed typing in TypeScript example.
746 - Fixed types in unit tests.
748 ## [2.3.6] - 2022-10-22
752 - Cleanup pool attributes and methods.
753 - Refine error types thrown.
757 - Fix continuous integration build on windows.
758 - Fix code coverage reporting by using c8 instead of nyc.
760 ## [2.3.5] - 2022-10-21
764 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
765 - Optimize tasks usage lookup implementation.
769 - Fix missed pool event emitter type export.
770 - Fix typedoc documentation generation.
772 ## [2.3.4] - 2022-10-17
776 - Fully automate release process with release-it.
780 - Optimize fair share task scheduling algorithm implementation.
781 - Update benchmarks versus external pools results with latest version.
783 ## [2.3.3] - 2022-10-15
787 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
789 ## [2.3.2] - 2022-10-14
793 - Optimize fair share worker selection strategy implementation.
797 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
799 ## [2.3.1] - 2022-10-13
803 - Pool worker choice strategies:
804 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
805 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
807 ## [2.2.2] - 2022-10-09
811 - Fixed `README.md` file.
813 ## [2.2.1] - 2022-10-08
817 - Dynamic worker choice strategy change at runtime.
819 ## [2.2.0] - 2022-01-05
823 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
825 ## [2.1.0] - 2021-08-29
829 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
833 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
834 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
835 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
836 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
838 ## [2.0.2] - 2021-05-12
842 - Fix `busy` event emission on fixed pool type
844 ## [2.0.1] - 2021-03-16
848 - Check if pool options are properly set.
849 - `busy` event is emitted on all pool types.
851 ## [2.0.0] - 2021-03-01
855 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
859 - `FullPool` event is now renamed to `busy`.
860 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
861 _Find more details on our JSDoc._
863 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
865 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
867 ### Pool options types declaration merge
869 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
871 #### New `export` strategy
875 const DynamicThreadPool = require('poolifier/lib/dynamic')
877 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
880 But you should always prefer just using
883 const { DynamicThreadPool } = require('poolifier')
886 #### New type definitions for input data and response
888 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
889 _This is not a limitation by poolifier but Node.js._
891 #### Public property replacements
893 `numWorkers` property is now `numberOfWorkers`
895 #### Internal (protected) properties and methods renaming
897 These properties are not intended for end users
899 - `id` => `nextMessageId`
901 These methods are not intended for end users
903 - `_chooseWorker` => `chooseWorker`
904 - `_newWorker` => `createWorker`
905 - `_execute` => `internalExecute`
906 - `_chooseWorker` => `chooseWorker`
907 - `_checkAlive` => `checkAlive`
909 - `_runAsync` => `runAsync`
911 ## [1.1.0] - 2020-05-21
915 - ThreadWorker support async functions as option
916 - Various external library patches
918 ## [1.0.0] - 2020-01-24
922 - FixedThreadPool implementation
923 - DynamicThreadPool implementation
924 - WorkerThread implementation to improve developer experience