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 - Do not pre-choose in WRR worker choice strategy to avoid bias.
14 ## [2.6.39] - 2023-08-30
18 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized .
20 ## [2.6.38] - 2023-08-30
24 - Bundle typescript types declaration into one file.
28 - Improve interleaved weighted round robin worker choice strategy implementation.
30 ## [2.6.37] - 2023-08-28
34 - Ensure unused worker usage statistics are deleted at runtime.
38 - Rename worker choice strategy options `choiceRetries` to `retries`.
39 - Avoid unnecessary branching in worker choice strategies.
41 ## [2.6.36] - 2023-08-27
45 - Fix pool `execute()` arguments check.
49 - Make continuous tasks stealing algorithm less aggressive.
50 - Fine tune tasks stealing algorithm under back pressure.
52 ## [2.6.35] - 2023-08-25
56 - Don't account worker usage statistics for tasks that have failed.
57 - Fix pool information runtime and wait time median computation.
61 - Update simple moving average implementation to use a circular buffer.
62 - Update simple moving median implementation to use a circular buffer.
63 - Account for stolen tasks in worker usage statistics and pool information.
67 - Continuous tasks stealing algorithm.
69 ## [2.6.34] - 2023-08-24
73 - Avoid cascading tasks stealing under back pressure.
77 - Add fastpath to queued tasks rescheduling.
79 ## [2.6.33] - 2023-08-24
83 - Fix queued tasks rescheduling.
87 - Rename tasks queue options `queueMaxSize` to `size`.
91 - Task stealing scheduling algorithm if tasks queueing is enabled.
93 ## [2.6.32] - 2023-08-23
97 - Ensure no task can be executed when the pool is destroyed.
101 - Add `queueMaxSize` option to tasks queue options.
102 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
103 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
105 ## [2.6.31] - 2023-08-20
109 - Fix worker choice strategy retries mechanism in some edge cases.
113 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
114 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
116 ## [2.6.30] - 2023-08-19
120 - Ensure pool event `backPressure` is emitted.
121 - Ensure pool event `full` is emitted only once.
122 - Ensure worker node cannot be instantiated without proper arguments.
124 ## [2.6.29] - 2023-08-18
128 - Fix race condition between ready and task functions worker message handling at startup.
129 - Fix duplicate task function worker usage statistics computation per task function.
130 - Update task function worker usage statistics if and only if there's at least two different task functions.
131 - Fix race condition at task function worker usage executing task computation leading to negative value.
135 - 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).
136 - Use back pressure detection in worker choice strategies.
137 - Add worker choice strategies retries mechanism if no worker is eligible.
139 ## [2.6.28] - 2023-08-16
143 - Ensure pool workers are properly initialized.
147 - HTTP server pool examples: express-cluster, express-hybrid.
151 - Remove now useless branching in worker hot code path.
153 ## [2.6.27] - 2023-08-15
157 - Add `KillHandler` type definition to exported types.
161 - Add `destroy` event to pool API.
163 ## [2.6.26] - 2023-08-15
167 - Add kill handler to worker options allowing to execute custom code when worker is killed.
168 - Add `listTaskFunctions()` method to pool API.
169 - SMTP server pool example: nodemailer.
171 ## [2.6.25] - 2023-08-13
175 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
176 - WebSocket server pool examples: ws-cluster, ws-hybrid.
178 ## [2.6.24] - 2023-08-12
182 - Add array of transferable objects to the `execute()` method arguments.
183 - WebSocket server pool examples: ws-worker_threads.
185 ## [2.6.23] - 2023-08-11
189 - 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.
193 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
194 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
196 ## [2.6.22] - 2023-08-10
200 - Add missing `types` field to package.json `exports`.
204 - Structure markdown documentation (PR #811).
206 ## [2.6.21] - 2023-08-03
210 - Improve code documentation.
211 - Code refactoring and cleanup for better maintainability and readability.
213 ## [2.6.20] - 2023-07-21
217 - Fix queued tasks redistribution on error task execution starvation.
218 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
222 - Drastically reduce lookups by worker in the worker nodes.
224 ## [2.6.19] - 2023-07-20
228 - Dedicated internal communication channel for worker_threads pools.
230 ## [2.6.18] - 2023-07-19
234 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
236 ## [2.6.17] - 2023-07-16
240 - Add `listTaskFunctions()` method to worker API.
242 ## [2.6.16] - 2023-07-12
246 - Fix pool startup detection.
247 - Fix worker task functions handling.
249 ## [2.6.15] - 2023-07-11
253 - Take into account worker node readiness in worker choice strategies.
255 ## [2.6.14] - 2023-07-10
259 - Fix task function statistics tracking.
261 ## [2.6.13] - 2023-07-10
265 - Add per task function statistics tracking.
266 - Add public methods to manipulate the worker task functions at runtime.
268 ## [2.6.12] - 2023-07-09
272 - Workaround import issue with `node:os` module in node 16.x.x.
274 ## [2.6.11] - 2023-07-09
278 - Fix pool readiness semantic.
280 ## [2.6.10] - 2023-07-08
284 - Ensure workers are not recreated on error at pool startup.
288 - Add `ready` and `strategy` fields to pool information.
289 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
290 - Add dynamic pool sizing checks.
292 ## [2.6.9] - 2023-07-07
296 - Recreate the right worker type on uncaught exception.
300 - Add minimum and maximum to internal measurement statistics.
301 - Add `runTime` and `waitTime` to pool information.
302 - Check worker inactive time only on dynamic worker.
304 ## [2.6.8] - 2023-07-03
308 - Brown paper bag release to fix version handling in pool information.
310 ## [2.6.7] - 2023-07-03
314 - Ensure worker queued tasks at error are reassigned to other pool workers.
318 - Add pool `utilization` ratio to pool information.
319 - Add `version` to pool information.
320 - Add worker information to worker nodes.
322 ## [2.6.6] - 2023-07-01
326 - Add safe helper `availableParallelism()` to help sizing the pool.
330 - Ensure message handler is only registered in worker.
332 ## [2.6.5] - 2023-06-27
336 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
340 - Artificial version bump to 2.6.5 to workaround publication issue.
341 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
342 - Ensure pool event is emitted before task error promise rejection.
343 - Fix queued tasks count computation.
347 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
349 ## [2.6.4] - 2023-06-27
353 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
357 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
358 - Ensure pool event is emitted before task error promise rejection.
359 - Fix queued tasks count computation.
363 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
365 ## [2.6.3] - 2023-06-19
369 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
370 - Update strategies internals after statistics computation.
374 - Optimize O(1) queue implementation.
376 ## [2.6.2] - 2023-06-12
380 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
382 ## [2.6.1] - 2023-06-10
386 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
390 - Fix average statistics computation: ensure failed tasks are not accounted.
392 ## [2.6.0] - 2023-06-09
396 - Add `LEAST_ELU` worker choice strategy (experimental).
397 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
401 - Refactor pool worker node usage internals.
402 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
403 - Breaking change: pool information `info` property object fields have been renamed.
407 - Fix wait time accounting.
408 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
409 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
411 ## [2.5.4] - 2023-06-07
415 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
419 - Compute statistics at the worker level only if needed.
420 - Add `worker_threads` options to thread pool options.
424 - Make the `LEAST_BUSY` strategy only relies on task runtime.
426 ## [2.5.3] - 2023-06-04
430 - Refine pool information content.
431 - Limit pool internals public exposure.
433 ## [2.5.2] - 2023-06-02
437 - Add `taskError` pool event for task execution error.
438 - Add pool information `info` property to pool.
439 - Emit pool information on `busy` and `full` pool events.
441 ## [2.5.1] - 2023-06-01
445 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
446 - Add `error` pool event for uncaught worker error.
448 ## [2.5.0] - 2023-05-31
452 - Switch pool event emitter to `EventEmitterAsyncResource`.
453 - Add tasks wait time accounting in per worker tasks usage.
454 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
458 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
460 ## [2.4.14] - 2023-05-09
464 - Ensure no undefined task runtime can land in the tasks history.
465 - Fix median computation implementation once again.
469 - Unit tests for median and queue implementations.
471 ## [2.4.13] - 2023-05-08
475 - Fix worker choice strategy options validation.
476 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
478 ## [2.4.12] - 2023-05-06
482 - Support multiple task functions per worker.
483 - Add custom worker weights support to worker choice strategies options.
487 - Use O(1) queue implementation for tasks queueing.
491 - Fix median computation implementation.
492 - Fix fair share worker choice strategy internals update.
494 ## [2.4.11] - 2023-04-23
498 - Optimize free worker finding in worker choice strategies.
500 ## [2.4.10] - 2023-04-15
504 - Fix typescript type definition for task function: ensure the input data is optional.
505 - Fix typescript type definition for pool execute(): ensure the input data is optional.
507 ## [2.4.9] - 2023-04-15
511 - Add tasks queue enablement runtime setter to pool.
512 - Add tasks queue options runtime setter to pool.
513 - Add worker choice strategy options runtime setter to pool.
517 - Remove the tasks queuing experimental status.
521 - Fix task function type definition and validation.
522 - Fix worker choice strategy options handling.
524 ## [2.4.8] - 2023-04-12
528 - Fix message between main worker and worker type definition for tasks.
529 - Fix code documentation.
531 ## [2.4.7] - 2023-04-11
535 - Add worker tasks queue options to pool options.
539 - Fix missing documentation.
541 ## [2.4.6] - 2023-04-10
545 - Ensure one task at a time is executed per worker with tasks queueing enabled.
546 - Properly count worker executing tasks with tasks queueing enabled.
548 ## [2.4.5] - 2023-04-09
552 - Use monotonic high resolution timer for worker tasks runtime.
553 - Add worker tasks median runtime to statistics.
554 - Add worker tasks queue (experimental).
556 ## [2.4.4] - 2023-04-07
560 - Add `PoolEvents` enumeration and `PoolEvent` type.
564 - Destroy worker only on alive check.
566 ## [2.4.3] - 2023-04-07
570 - Fix typedoc generation with inheritance.
572 ## [2.4.2] - 2023-04-06
576 - Add `full` event to dynamic pool.
577 - Keep worker choice strategy in memory for conditional reuse.
581 - Fix possible negative worker key at worker removal in worker choice strategies.
583 ## [2.4.1] - 2023-04-05
587 - Optimize worker choice strategy for dynamic pool.
591 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
593 ## [2.4.0] - 2023-04-04
597 - Add `LESS_BUSY` worker choice strategy.
601 - Optimize worker storage in pool.
602 - Optimize worker alive status check.
603 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
604 - Optimize `LESS_USED` worker choice strategy.
605 - Update benchmarks versus external threads pools.
606 - Optimize tasks usage statistics requirements for worker choice strategy.
610 - Ensure trimmable characters are checked at pool initialization.
611 - Fix message id integer overflow.
612 - Fix pool worker removal in worker choice strategy internals.
613 - Fix package publication with pnpm.
615 ## [2.4.0-3] - 2023-04-04
619 - Add `LESS_BUSY` worker choice strategy.
623 - Optimize worker storage in pool.
624 - Optimize worker alive status check.
625 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
626 - Optimize `LESS_USED` worker choice strategy.
627 - Update benchmarks versus external threads pools.
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 ## [2.4.0-2] - 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.
654 - Fix package publication with pnpm.
656 ## [2.4.0-1] - 2023-04-03
660 - Add `LESS_BUSY` worker choice strategy.
664 - Optimize worker storage in pool.
665 - Optimize worker alive status check.
666 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
667 - Optimize `LESS_USED` worker choice strategy.
671 - Ensure trimmable characters are checked at pool initialization.
672 - Fix message id integer overflow.
673 - Fix pool worker removal in worker choice strategy internals.
675 ## [2.4.0-0] - 2023-04-03
679 - Add `LESS_BUSY` worker choice strategy.
683 - Optimize worker storage in pool.
684 - Optimize worker alive status check.
685 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
686 - Optimize `LESS_USED` worker choice strategy.
690 - Ensure trimmable characters are checked at pool initialization.
691 - Fix message id integer overflow.
692 - Fix pool worker removal in worker choice strategy internals.
694 ## [2.3.10] - 2023-03-18
698 - Fix package.json `exports` syntax for ESM and CommonJS.
702 - Permit SemVer pre-release publication.
704 ## [2.3.10-2] - 2023-03-18
708 - Fix package.json `exports` syntax for ESM and CommonJS.
710 ## [2.3.10-1] - 2023-03-18
714 - Permit SemVer pre-release publication.
716 ## [2.3.10-0] - 2023-03-18
720 - Fix package.json `exports` syntax for ESM and CommonJS.
722 ## [2.3.9] - 2023-03-18
726 - Introduce ESM module support along with CommonJS one.
730 - Fix brown paper bag bug referencing the same object literal.
732 ## [2.3.8] - 2023-03-18
736 - Switch internal benchmarking code to benny.
737 - Switch to TypeScript 5.x.x.
738 - Switch rollup bundler plugins to core ones.
739 - Switch to TSDoc syntax.
740 - Enforce conventional commits.
744 - Fix random integer generator.
745 - Fix worker choice strategy pool type identification at initialization.
747 ## [2.3.7] - 2022-10-23
751 - Switch to open collective FOSS project funding platform.
752 - Switch to ts-standard linter configuration on TypeScript code.
756 - Fixed missing async on pool execute method.
757 - Fixed typing in TypeScript example.
758 - Fixed types in unit tests.
760 ## [2.3.6] - 2022-10-22
764 - Cleanup pool attributes and methods.
765 - Refine error types thrown.
769 - Fix continuous integration build on windows.
770 - Fix code coverage reporting by using c8 instead of nyc.
772 ## [2.3.5] - 2022-10-21
776 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
777 - Optimize tasks usage lookup implementation.
781 - Fix missed pool event emitter type export.
782 - Fix typedoc documentation generation.
784 ## [2.3.4] - 2022-10-17
788 - Fully automate release process with release-it.
792 - Optimize fair share task scheduling algorithm implementation.
793 - Update benchmarks versus external pools results with latest version.
795 ## [2.3.3] - 2022-10-15
799 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
801 ## [2.3.2] - 2022-10-14
805 - Optimize fair share worker selection strategy implementation.
809 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
811 ## [2.3.1] - 2022-10-13
815 - Pool worker choice strategies:
816 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
817 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
819 ## [2.2.2] - 2022-10-09
823 - Fixed `README.md` file.
825 ## [2.2.1] - 2022-10-08
829 - Dynamic worker choice strategy change at runtime.
831 ## [2.2.0] - 2022-01-05
835 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
837 ## [2.1.0] - 2021-08-29
841 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
845 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
846 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
847 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
848 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
850 ## [2.0.2] - 2021-05-12
854 - Fix `busy` event emission on fixed pool type
856 ## [2.0.1] - 2021-03-16
860 - Check if pool options are properly set.
861 - `busy` event is emitted on all pool types.
863 ## [2.0.0] - 2021-03-01
867 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
871 - `FullPool` event is now renamed to `busy`.
872 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
873 _Find more details on our JSDoc._
875 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
877 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
879 ### Pool options types declaration merge
881 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
883 #### New `export` strategy
887 const DynamicThreadPool = require('poolifier/lib/dynamic')
889 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
892 But you should always prefer just using
895 const { DynamicThreadPool } = require('poolifier')
898 #### New type definitions for input data and response
900 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
901 _This is not a limitation by poolifier but Node.js._
903 #### Public property replacements
905 `numWorkers` property is now `numberOfWorkers`
907 #### Internal (protected) properties and methods renaming
909 These properties are not intended for end users
911 - `id` => `nextMessageId`
913 These methods are not intended for end users
915 - `_chooseWorker` => `chooseWorker`
916 - `_newWorker` => `createWorker`
917 - `_execute` => `internalExecute`
918 - `_chooseWorker` => `chooseWorker`
919 - `_checkAlive` => `checkAlive`
921 - `_runAsync` => `runAsync`
923 ## [1.1.0] - 2020-05-21
927 - ThreadWorker support async functions as option
928 - Various external library patches
930 ## [1.0.0] - 2020-01-24
934 - FixedThreadPool implementation
935 - DynamicThreadPool implementation
936 - WorkerThread implementation to improve developer experience