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 ## [2.7.5] - 2023-10-03
14 - Use `EventEmitterAsyncResource` type from `@types/node` for pool event emitter. TypeScript users will need to update to latest `@types/node` version.
16 ## [2.7.4] - 2023-09-25
20 - Fix source maps (bundler issue).
22 ## [2.7.3] - 2023-09-24
26 - Convert pool event emitter to event emitter async resource.
28 ## [2.7.2] - 2023-09-23
32 - Add source maps to npm package to ease debugging.
36 - Continuous benchmarking versus other worker pools: [https://poolifier.github.io/benchmark](https://poolifier.github.io/benchmark).
38 ## [2.7.1] - 2023-09-20
42 - Ensure worker message listener used one time are removed after usage.
44 ## [2.7.0] - 2023-09-19
48 - Fix task stealing related tasks queue options handling at runtime.
52 - Rename `listTaskFunctions()` to `listTaskFunctionNames()` in pool and worker API.
56 - Add `hasTaskFunction()`, `addTaskFunction()`, `removeTaskFunction()`, `setDefaultTaskFunction()` methods to pool API: [PR #1148](https://github.com/poolifier/poolifier/pull/1148).
57 - Stricter worker constructor arguments validation.
59 ## [2.6.45] - 2023-09-17
63 - Disable publication on GitHub packages registry on release until authentication issue is fixed.
67 - Add `startWorkers` to pool options to whether start the minimum number of workers at pool initialization or not.
68 - Add `start()` method to pool API to start the minimum number of workers.
69 - Add `taskStealing` and `tasksStealingOnPressure` to tasks queue options to whether enable task stealing or not and whether enable tasks stealing under back pressure or not.
70 - Continuous internal benchmarking: [https://poolifier.github.io/benchmark-results/dev/bench](https://poolifier.github.io/benchmark-results/dev/bench).
72 ## [2.6.44] - 2023-09-08
76 - Use a dedicated PAT to publish on GitHub packages registry.
80 - Publish on GitHub packages registry on release.
84 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
86 ## [2.6.43] - 2023-09-08
90 - Publish on GitHub packages registry on release.
94 - Switch from rome to biome: [PR #1128](https://github.com/poolifier/poolifier/pull/1128).
96 ## [2.6.42] - 2023-09-06
100 - Optimize hot code paths implementation: avoid unnecessary branching, add and use optimized helpers (min, max), use reduce() array helper, ...
102 ## [2.6.41] - 2023-09-03
106 - Optimize worker choice strategies implementation.
108 ## [2.6.40] - 2023-09-01
112 - Do not pre-choose in WRR worker choice strategy to avoid bias.
113 - Avoid array out of bound in worker choice strategies after worker node removal.
115 ## [2.6.39] - 2023-08-30
119 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized.
121 ## [2.6.38] - 2023-08-30
125 - Bundle typescript types declaration into one file.
129 - Improve interleaved weighted round robin worker choice strategy implementation.
131 ## [2.6.37] - 2023-08-28
135 - Ensure unused worker usage statistics are deleted at runtime.
139 - Rename worker choice strategy options `choiceRetries` to `retries`.
140 - Avoid unnecessary branching in worker choice strategies.
142 ## [2.6.36] - 2023-08-27
146 - Fix pool `execute()` arguments check.
150 - Make continuous tasks stealing algorithm less aggressive.
151 - Fine tune tasks stealing algorithm under back pressure.
153 ## [2.6.35] - 2023-08-25
157 - Don't account worker usage statistics for tasks that have failed.
158 - Fix pool information runtime and wait time median computation.
162 - Update simple moving average implementation to use a circular buffer.
163 - Update simple moving median implementation to use a circular buffer.
164 - Account for stolen tasks in worker usage statistics and pool information.
168 - Continuous tasks stealing algorithm.
170 ## [2.6.34] - 2023-08-24
174 - Avoid cascading tasks stealing under back pressure.
178 - Add fastpath to queued tasks rescheduling.
180 ## [2.6.33] - 2023-08-24
184 - Fix queued tasks rescheduling.
188 - Rename tasks queue options `queueMaxSize` to `size`.
192 - Task stealing scheduling algorithm if tasks queueing is enabled.
194 ## [2.6.32] - 2023-08-23
198 - Ensure no task can be executed when the pool is destroyed.
202 - Add `queueMaxSize` option to tasks queue options.
203 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
204 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
206 ## [2.6.31] - 2023-08-20
210 - Fix worker choice strategy retries mechanism in some edge cases.
214 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
215 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
217 ## [2.6.30] - 2023-08-19
221 - Ensure pool event `backPressure` is emitted.
222 - Ensure pool event `full` is emitted only once.
223 - Ensure worker node cannot be instantiated without proper arguments.
225 ## [2.6.29] - 2023-08-18
229 - Fix race condition between ready and task functions worker message handling at startup.
230 - Fix duplicate task function worker usage statistics computation per task function.
231 - Update task function worker usage statistics if and only if there's at least two different task functions.
232 - Fix race condition at task function worker usage executing task computation leading to negative value.
236 - 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).
237 - Use back pressure detection in worker choice strategies.
238 - Add worker choice strategies retries mechanism if no worker is eligible.
240 ## [2.6.28] - 2023-08-16
244 - Ensure pool workers are properly initialized.
248 - HTTP server pool examples: express-cluster, express-hybrid.
252 - Remove now useless branching in worker hot code path.
254 ## [2.6.27] - 2023-08-15
258 - Add `KillHandler` type definition to exported types.
262 - Add `destroy` event to pool API.
264 ## [2.6.26] - 2023-08-15
268 - Add kill handler to worker options allowing to execute custom code when worker is killed.
269 - Add `listTaskFunctions()` method to pool API.
270 - SMTP client pool example: nodemailer.
272 ## [2.6.25] - 2023-08-13
276 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
277 - WebSocket server pool examples: ws-cluster, ws-hybrid.
279 ## [2.6.24] - 2023-08-12
283 - Add array of transferable objects to the `execute()` method arguments.
284 - WebSocket server pool examples: ws-worker_threads.
286 ## [2.6.23] - 2023-08-11
290 - 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.
294 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
295 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
297 ## [2.6.22] - 2023-08-10
301 - Add missing `types` field to package.json `exports`.
305 - Structure markdown documentation (PR #811).
307 ## [2.6.21] - 2023-08-03
311 - Improve code documentation.
312 - Code refactoring and cleanup for better maintainability and readability.
314 ## [2.6.20] - 2023-07-21
318 - Fix queued tasks redistribution on error task execution starvation.
319 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
323 - Drastically reduce lookups by worker in the worker nodes.
325 ## [2.6.19] - 2023-07-20
329 - Dedicated internal communication channel for worker_threads pools.
331 ## [2.6.18] - 2023-07-19
335 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
337 ## [2.6.17] - 2023-07-16
341 - Add `listTaskFunctions()` method to worker API.
343 ## [2.6.16] - 2023-07-12
347 - Fix pool startup detection.
348 - Fix worker task functions handling.
350 ## [2.6.15] - 2023-07-11
354 - Take into account worker node readiness in worker choice strategies.
356 ## [2.6.14] - 2023-07-10
360 - Fix task function statistics tracking.
362 ## [2.6.13] - 2023-07-10
366 - Add per task function statistics tracking.
367 - Add public methods to manipulate the worker task functions at runtime.
369 ## [2.6.12] - 2023-07-09
373 - Workaround import issue with `node:os` module in node 16.x.x.
375 ## [2.6.11] - 2023-07-09
379 - Fix pool readiness semantic.
381 ## [2.6.10] - 2023-07-08
385 - Ensure workers are not recreated on error at pool startup.
389 - Add `ready` and `strategy` fields to pool information.
390 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
391 - Add dynamic pool sizing checks.
393 ## [2.6.9] - 2023-07-07
397 - Recreate the right worker type on uncaught exception.
401 - Add minimum and maximum to internal measurement statistics.
402 - Add `runTime` and `waitTime` to pool information.
403 - Check worker inactive time only on dynamic worker.
405 ## [2.6.8] - 2023-07-03
409 - Brown paper bag release to fix version handling in pool information.
411 ## [2.6.7] - 2023-07-03
415 - Ensure worker queued tasks at error are reassigned to other pool workers.
419 - Add pool `utilization` ratio to pool information.
420 - Add `version` to pool information.
421 - Add worker information to worker nodes.
423 ## [2.6.6] - 2023-07-01
427 - Add safe helper `availableParallelism()` to help sizing the pool.
431 - Ensure message handler is only registered in worker.
433 ## [2.6.5] - 2023-06-27
437 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
441 - Artificial version bump to 2.6.5 to workaround publication issue.
442 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
443 - Ensure pool event is emitted before task error promise rejection.
444 - Fix queued tasks count computation.
448 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
450 ## [2.6.4] - 2023-06-27
454 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
458 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
459 - Ensure pool event is emitted before task error promise rejection.
460 - Fix queued tasks count computation.
464 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
466 ## [2.6.3] - 2023-06-19
470 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
471 - Update strategies internals after statistics computation.
475 - Optimize O(1) queue implementation.
477 ## [2.6.2] - 2023-06-12
481 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
483 ## [2.6.1] - 2023-06-10
487 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
491 - Fix average statistics computation: ensure failed tasks are not accounted.
493 ## [2.6.0] - 2023-06-09
497 - Add `LEAST_ELU` worker choice strategy (experimental).
498 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
502 - Refactor pool worker node usage internals.
503 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
504 - Breaking change: pool information `info` property object fields have been renamed.
508 - Fix wait time accounting.
509 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
510 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
512 ## [2.5.4] - 2023-06-07
516 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
520 - Compute statistics at the worker level only if needed.
521 - Add `worker_threads` options to thread pool options.
525 - Make the `LEAST_BUSY` strategy only relies on task runtime.
527 ## [2.5.3] - 2023-06-04
531 - Refine pool information content.
532 - Limit pool internals public exposure.
534 ## [2.5.2] - 2023-06-02
538 - Add `taskError` pool event for task execution error.
539 - Add pool information `info` property to pool.
540 - Emit pool information on `busy` and `full` pool events.
542 ## [2.5.1] - 2023-06-01
546 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
547 - Add `error` pool event for uncaught worker error.
549 ## [2.5.0] - 2023-05-31
553 - Switch pool event emitter to `EventEmitterAsyncResource`.
554 - Add tasks wait time accounting in per worker tasks usage.
555 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
559 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
561 ## [2.4.14] - 2023-05-09
565 - Ensure no undefined task runtime can land in the tasks history.
566 - Fix median computation implementation once again.
570 - Unit tests for median and queue implementations.
572 ## [2.4.13] - 2023-05-08
576 - Fix worker choice strategy options validation.
577 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
579 ## [2.4.12] - 2023-05-06
583 - Support multiple task functions per worker.
584 - Add custom worker weights support to worker choice strategies options.
588 - Use O(1) queue implementation for tasks queueing.
592 - Fix median computation implementation.
593 - Fix fair share worker choice strategy internals update.
595 ## [2.4.11] - 2023-04-23
599 - Optimize free worker finding in worker choice strategies.
601 ## [2.4.10] - 2023-04-15
605 - Fix typescript type definition for task function: ensure the input data is optional.
606 - Fix typescript type definition for pool execute(): ensure the input data is optional.
608 ## [2.4.9] - 2023-04-15
612 - Add tasks queue enablement runtime setter to pool.
613 - Add tasks queue options runtime setter to pool.
614 - Add worker choice strategy options runtime setter to pool.
618 - Remove the tasks queuing experimental status.
622 - Fix task function type definition and validation.
623 - Fix worker choice strategy options handling.
625 ## [2.4.8] - 2023-04-12
629 - Fix message between main worker and worker type definition for tasks.
630 - Fix code documentation.
632 ## [2.4.7] - 2023-04-11
636 - Add worker tasks queue options to pool options.
640 - Fix missing documentation.
642 ## [2.4.6] - 2023-04-10
646 - Ensure one task at a time is executed per worker with tasks queueing enabled.
647 - Properly count worker executing tasks with tasks queueing enabled.
649 ## [2.4.5] - 2023-04-09
653 - Use monotonic high resolution timer for worker tasks runtime.
654 - Add worker tasks median runtime to statistics.
655 - Add worker tasks queue (experimental).
657 ## [2.4.4] - 2023-04-07
661 - Add `PoolEvents` enumeration and `PoolEvent` type.
665 - Destroy worker only on alive check.
667 ## [2.4.3] - 2023-04-07
671 - Fix typedoc generation with inheritance.
673 ## [2.4.2] - 2023-04-06
677 - Add `full` event to dynamic pool.
678 - Keep worker choice strategy in memory for conditional reuse.
682 - Fix possible negative worker key at worker removal in worker choice strategies.
684 ## [2.4.1] - 2023-04-05
688 - Optimize worker choice strategy for dynamic pool.
692 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
694 ## [2.4.0] - 2023-04-04
698 - Add `LESS_BUSY` worker choice strategy.
702 - Optimize worker storage in pool.
703 - Optimize worker alive status check.
704 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
705 - Optimize `LESS_USED` worker choice strategy.
706 - Update benchmark versus external threads pools.
707 - Optimize tasks usage statistics requirements for worker choice strategy.
711 - Ensure trimmable characters are checked at pool initialization.
712 - Fix message id integer overflow.
713 - Fix pool worker removal in worker choice strategy internals.
714 - Fix package publication with pnpm.
716 ## [2.4.0-3] - 2023-04-04
720 - Add `LESS_BUSY` worker choice strategy.
724 - Optimize worker storage in pool.
725 - Optimize worker alive status check.
726 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
727 - Optimize `LESS_USED` worker choice strategy.
728 - Update benchmark versus external threads pools.
732 - Ensure trimmable characters are checked at pool initialization.
733 - Fix message id integer overflow.
734 - Fix pool worker removal in worker choice strategy internals.
735 - Fix package publication with pnpm.
737 ## [2.4.0-2] - 2023-04-03
741 - Add `LESS_BUSY` worker choice strategy.
745 - Optimize worker storage in pool.
746 - Optimize worker alive status check.
747 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
748 - Optimize `LESS_USED` worker choice strategy.
752 - Ensure trimmable characters are checked at pool initialization.
753 - Fix message id integer overflow.
754 - Fix pool worker removal in worker choice strategy internals.
755 - Fix package publication with pnpm.
757 ## [2.4.0-1] - 2023-04-03
761 - Add `LESS_BUSY` worker choice strategy.
765 - Optimize worker storage in pool.
766 - Optimize worker alive status check.
767 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
768 - Optimize `LESS_USED` worker choice strategy.
772 - Ensure trimmable characters are checked at pool initialization.
773 - Fix message id integer overflow.
774 - Fix pool worker removal in worker choice strategy internals.
776 ## [2.4.0-0] - 2023-04-03
780 - Add `LESS_BUSY` worker choice strategy.
784 - Optimize worker storage in pool.
785 - Optimize worker alive status check.
786 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
787 - Optimize `LESS_USED` worker choice strategy.
791 - Ensure trimmable characters are checked at pool initialization.
792 - Fix message id integer overflow.
793 - Fix pool worker removal in worker choice strategy internals.
795 ## [2.3.10] - 2023-03-18
799 - Fix package.json `exports` syntax for ESM and CommonJS.
803 - Permit SemVer pre-release publication.
805 ## [2.3.10-2] - 2023-03-18
809 - Fix package.json `exports` syntax for ESM and CommonJS.
811 ## [2.3.10-1] - 2023-03-18
815 - Permit SemVer pre-release publication.
817 ## [2.3.10-0] - 2023-03-18
821 - Fix package.json `exports` syntax for ESM and CommonJS.
823 ## [2.3.9] - 2023-03-18
827 - Introduce ESM module support along with CommonJS one.
831 - Fix brown paper bag bug referencing the same object literal.
833 ## [2.3.8] - 2023-03-18
837 - Switch internal benchmarking code to benny.
838 - Switch to TypeScript 5.x.x.
839 - Switch rollup bundler plugins to core ones.
840 - Switch to TSDoc syntax.
841 - Enforce conventional commits.
845 - Fix random integer generator.
846 - Fix worker choice strategy pool type identification at initialization.
848 ## [2.3.7] - 2022-10-23
852 - Switch to open collective FOSS project funding platform.
853 - Switch to ts-standard linter configuration on TypeScript code.
857 - Fixed missing async on pool execute method.
858 - Fixed typing in TypeScript example.
859 - Fixed types in unit tests.
861 ## [2.3.6] - 2022-10-22
865 - Cleanup pool attributes and methods.
866 - Refine error types thrown.
870 - Fix continuous integration build on windows.
871 - Fix code coverage reporting by using c8 instead of nyc.
873 ## [2.3.5] - 2022-10-21
877 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
878 - Optimize tasks usage lookup implementation.
882 - Fix missed pool event emitter type export.
883 - Fix typedoc documentation generation.
885 ## [2.3.4] - 2022-10-17
889 - Fully automate release process with release-it.
893 - Optimize fair share task scheduling algorithm implementation.
894 - Update benchmark versus external pools results with latest version.
896 ## [2.3.3] - 2022-10-15
900 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
902 ## [2.3.2] - 2022-10-14
906 - Optimize fair share worker selection strategy implementation.
910 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
912 ## [2.3.1] - 2022-10-13
916 - Pool worker choice strategies:
917 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
918 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
920 ## [2.2.2] - 2022-10-09
924 - Fixed `README.md` file.
926 ## [2.2.1] - 2022-10-08
930 - Dynamic worker choice strategy change at runtime.
932 ## [2.2.0] - 2022-01-05
936 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
938 ## [2.1.0] - 2021-08-29
942 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
946 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
947 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
948 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
949 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
951 ## [2.0.2] - 2021-05-12
955 - Fix `busy` event emission on fixed pool type
957 ## [2.0.1] - 2021-03-16
961 - Check if pool options are properly set.
962 - `busy` event is emitted on all pool types.
964 ## [2.0.0] - 2021-03-01
968 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
972 - `FullPool` event is now renamed to `busy`.
973 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
974 _Find more details on our JSDoc._
976 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
978 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
980 ### Pool options types declaration merge
982 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
984 #### New `export` strategy
988 const DynamicThreadPool = require('poolifier/lib/dynamic')
990 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
993 But you should always prefer just using
996 const { DynamicThreadPool } = require('poolifier')
999 #### New type definitions for input data and response
1001 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
1002 _This is not a limitation by poolifier but Node.js._
1004 #### Public property replacements
1006 `numWorkers` property is now `numberOfWorkers`
1008 #### Internal (protected) properties and methods renaming
1010 These properties are not intended for end users
1012 - `id` => `nextMessageId`
1014 These methods are not intended for end users
1016 - `_chooseWorker` => `chooseWorker`
1017 - `_newWorker` => `createWorker`
1018 - `_execute` => `internalExecute`
1019 - `_chooseWorker` => `chooseWorker`
1020 - `_checkAlive` => `checkAlive`
1022 - `_runAsync` => `runAsync`
1024 ## [1.1.0] - 2020-05-21
1028 - ThreadWorker support async functions as option
1029 - Various external library patches
1031 ## [1.0.0] - 2020-01-24
1035 - FixedThreadPool implementation
1036 - DynamicThreadPool implementation
1037 - WorkerThread implementation to improve developer experience