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.
14 ## [2.6.37] - 2023-08-28
18 - Ensure unused worker usage statistics are deleted at runtime.
22 - Rename worker choice strategy options `choiceRetries` to `retries`.
23 - Avoid unnecessary branching in worker choice strategies.
25 ## [2.6.36] - 2023-08-27
29 - Fix pool `execute()` arguments check.
33 - Make continuous tasks stealing algorithm less aggressive.
34 - Fine tune tasks stealing algorithm under back pressure.
36 ## [2.6.35] - 2023-08-25
40 - Don't account worker usage statistics for tasks that have failed.
41 - Fix pool information runtime and wait time median computation.
45 - Update simple moving average implementation to use a circular buffer.
46 - Update simple moving median implementation to use a circular buffer.
47 - Account for stolen tasks in worker usage statistics and pool information.
51 - Continuous tasks stealing algorithm.
53 ## [2.6.34] - 2023-08-24
57 - Avoid cascading tasks stealing under back pressure.
61 - Add fastpath to queued tasks rescheduling.
63 ## [2.6.33] - 2023-08-24
67 - Fix queued tasks rescheduling.
71 - Rename tasks queue options `queueMaxSize` to `size`.
75 - Task stealing scheduling algorithm if tasks queueing is enabled.
77 ## [2.6.32] - 2023-08-23
81 - Ensure no task can be executed when the pool is destroyed.
85 - Add `queueMaxSize` option to tasks queue options.
86 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
87 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
89 ## [2.6.31] - 2023-08-20
93 - Fix worker choice strategy retries mechanism in some edge cases.
97 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
98 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
100 ## [2.6.30] - 2023-08-19
104 - Ensure pool event `backPressure` is emitted.
105 - Ensure pool event `full` is emitted only once.
106 - Ensure worker node cannot be instantiated without proper arguments.
108 ## [2.6.29] - 2023-08-18
112 - Fix race condition between ready and task functions worker message handling at startup.
113 - Fix duplicate task function worker usage statistics computation per task function.
114 - Update task function worker usage statistics if and only if there's at least two different task functions.
115 - Fix race condition at task function worker usage executing task computation leading to negative value.
119 - 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).
120 - Use back pressure detection in worker choice strategies.
121 - Add worker choice strategies retries mechanism if no worker is eligible.
123 ## [2.6.28] - 2023-08-16
127 - Ensure pool workers are properly initialized.
131 - HTTP server pool examples: express-cluster, express-hybrid.
135 - Remove now useless branching in worker hot code path.
137 ## [2.6.27] - 2023-08-15
141 - Add `KillHandler` type definition to exported types.
145 - Add `destroy` event to pool API.
147 ## [2.6.26] - 2023-08-15
151 - Add kill handler to worker options allowing to execute custom code when worker is killed.
152 - Add `listTaskFunctions()` method to pool API.
153 - SMTP server pool example: nodemailer.
155 ## [2.6.25] - 2023-08-13
159 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
160 - WebSocket server pool examples: ws-cluster, ws-hybrid.
162 ## [2.6.24] - 2023-08-12
166 - Add array of transferable objects to the `execute()` method arguments.
167 - WebSocket server pool examples: ws-worker_threads.
169 ## [2.6.23] - 2023-08-11
173 - 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.
177 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
178 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
180 ## [2.6.22] - 2023-08-10
184 - Add missing `types` field to package.json `exports`.
188 - Structure markdown documentation (PR #811).
190 ## [2.6.21] - 2023-08-03
194 - Improve code documentation.
195 - Code refactoring and cleanup for better maintainability and readability.
197 ## [2.6.20] - 2023-07-21
201 - Fix queued tasks redistribution on error task execution starvation.
202 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
206 - Drastically reduce lookups by worker in the worker nodes.
208 ## [2.6.19] - 2023-07-20
212 - Dedicated internal communication channel for worker_threads pools.
214 ## [2.6.18] - 2023-07-19
218 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
220 ## [2.6.17] - 2023-07-16
224 - Add `listTaskFunctions()` method to worker API.
226 ## [2.6.16] - 2023-07-12
230 - Fix pool startup detection.
231 - Fix worker task functions handling.
233 ## [2.6.15] - 2023-07-11
237 - Take into account worker node readiness in worker choice strategies.
239 ## [2.6.14] - 2023-07-10
243 - Fix task function statistics tracking.
245 ## [2.6.13] - 2023-07-10
249 - Add per task function statistics tracking.
250 - Add public methods to manipulate the worker task functions at runtime.
252 ## [2.6.12] - 2023-07-09
256 - Workaround import issue with `node:os` module in node 16.x.x.
258 ## [2.6.11] - 2023-07-09
262 - Fix pool readiness semantic.
264 ## [2.6.10] - 2023-07-08
268 - Ensure workers are not recreated on error at pool startup.
272 - Add `ready` and `strategy` fields to pool information.
273 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
274 - Add dynamic pool sizing checks.
276 ## [2.6.9] - 2023-07-07
280 - Recreate the right worker type on uncaught exception.
284 - Add minimum and maximum to internal measurement statistics.
285 - Add `runTime` and `waitTime` to pool information.
286 - Check worker inactive time only on dynamic worker.
288 ## [2.6.8] - 2023-07-03
292 - Brown paper bag release to fix version handling in pool information.
294 ## [2.6.7] - 2023-07-03
298 - Ensure worker queued tasks at error are reassigned to other pool workers.
302 - Add pool `utilization` ratio to pool information.
303 - Add `version` to pool information.
304 - Add worker information to worker nodes.
306 ## [2.6.6] - 2023-07-01
310 - Add safe helper `availableParallelism()` to help sizing the pool.
314 - Ensure message handler is only registered in worker.
316 ## [2.6.5] - 2023-06-27
320 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
324 - Artificial version bump to 2.6.5 to workaround publication issue.
325 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
326 - Ensure pool event is emitted before task error promise rejection.
327 - Fix queued tasks count computation.
331 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
333 ## [2.6.4] - 2023-06-27
337 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
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 ## [2.6.3] - 2023-06-19
353 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
354 - Update strategies internals after statistics computation.
358 - Optimize O(1) queue implementation.
360 ## [2.6.2] - 2023-06-12
364 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
366 ## [2.6.1] - 2023-06-10
370 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
374 - Fix average statistics computation: ensure failed tasks are not accounted.
376 ## [2.6.0] - 2023-06-09
380 - Add `LEAST_ELU` worker choice strategy (experimental).
381 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
385 - Refactor pool worker node usage internals.
386 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
387 - Breaking change: pool information `info` property object fields have been renamed.
391 - Fix wait time accounting.
392 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
393 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
395 ## [2.5.4] - 2023-06-07
399 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
403 - Compute statistics at the worker level only if needed.
404 - Add `worker_threads` options to thread pool options.
408 - Make the `LEAST_BUSY` strategy only relies on task runtime.
410 ## [2.5.3] - 2023-06-04
414 - Refine pool information content.
415 - Limit pool internals public exposure.
417 ## [2.5.2] - 2023-06-02
421 - Add `taskError` pool event for task execution error.
422 - Add pool information `info` property to pool.
423 - Emit pool information on `busy` and `full` pool events.
425 ## [2.5.1] - 2023-06-01
429 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
430 - Add `error` pool event for uncaught worker error.
432 ## [2.5.0] - 2023-05-31
436 - Switch pool event emitter to `EventEmitterAsyncResource`.
437 - Add tasks wait time accounting in per worker tasks usage.
438 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
442 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
444 ## [2.4.14] - 2023-05-09
448 - Ensure no undefined task runtime can land in the tasks history.
449 - Fix median computation implementation once again.
453 - Unit tests for median and queue implementations.
455 ## [2.4.13] - 2023-05-08
459 - Fix worker choice strategy options validation.
460 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
462 ## [2.4.12] - 2023-05-06
466 - Support multiple task functions per worker.
467 - Add custom worker weights support to worker choice strategies options.
471 - Use O(1) queue implementation for tasks queueing.
475 - Fix median computation implementation.
476 - Fix fair share worker choice strategy internals update.
478 ## [2.4.11] - 2023-04-23
482 - Optimize free worker finding in worker choice strategies.
484 ## [2.4.10] - 2023-04-15
488 - Fix typescript type definition for task function: ensure the input data is optional.
489 - Fix typescript type definition for pool execute(): ensure the input data is optional.
491 ## [2.4.9] - 2023-04-15
495 - Add tasks queue enablement runtime setter to pool.
496 - Add tasks queue options runtime setter to pool.
497 - Add worker choice strategy options runtime setter to pool.
501 - Remove the tasks queuing experimental status.
505 - Fix task function type definition and validation.
506 - Fix worker choice strategy options handling.
508 ## [2.4.8] - 2023-04-12
512 - Fix message between main worker and worker type definition for tasks.
513 - Fix code documentation.
515 ## [2.4.7] - 2023-04-11
519 - Add worker tasks queue options to pool options.
523 - Fix missing documentation.
525 ## [2.4.6] - 2023-04-10
529 - Ensure one task at a time is executed per worker with tasks queueing enabled.
530 - Properly count worker executing tasks with tasks queueing enabled.
532 ## [2.4.5] - 2023-04-09
536 - Use monotonic high resolution timer for worker tasks runtime.
537 - Add worker tasks median runtime to statistics.
538 - Add worker tasks queue (experimental).
540 ## [2.4.4] - 2023-04-07
544 - Add `PoolEvents` enumeration and `PoolEvent` type.
548 - Destroy worker only on alive check.
550 ## [2.4.3] - 2023-04-07
554 - Fix typedoc generation with inheritance.
556 ## [2.4.2] - 2023-04-06
560 - Add `full` event to dynamic pool.
561 - Keep worker choice strategy in memory for conditional reuse.
565 - Fix possible negative worker key at worker removal in worker choice strategies.
567 ## [2.4.1] - 2023-04-05
571 - Optimize worker choice strategy for dynamic pool.
575 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
577 ## [2.4.0] - 2023-04-04
581 - Add `LESS_BUSY` worker choice strategy.
585 - Optimize worker storage in pool.
586 - Optimize worker alive status check.
587 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
588 - Optimize `LESS_USED` worker choice strategy.
589 - Update benchmarks versus external threads pools.
590 - Optimize tasks usage statistics requirements for worker choice strategy.
594 - Ensure trimmable characters are checked at pool initialization.
595 - Fix message id integer overflow.
596 - Fix pool worker removal in worker choice strategy internals.
597 - Fix package publication with pnpm.
599 ## [2.4.0-3] - 2023-04-04
603 - Add `LESS_BUSY` worker choice strategy.
607 - Optimize worker storage in pool.
608 - Optimize worker alive status check.
609 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
610 - Optimize `LESS_USED` worker choice strategy.
611 - Update benchmarks versus external threads pools.
615 - Ensure trimmable characters are checked at pool initialization.
616 - Fix message id integer overflow.
617 - Fix pool worker removal in worker choice strategy internals.
618 - Fix package publication with pnpm.
620 ## [2.4.0-2] - 2023-04-03
624 - Add `LESS_BUSY` worker choice strategy.
628 - Optimize worker storage in pool.
629 - Optimize worker alive status check.
630 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
631 - Optimize `LESS_USED` worker choice strategy.
635 - Ensure trimmable characters are checked at pool initialization.
636 - Fix message id integer overflow.
637 - Fix pool worker removal in worker choice strategy internals.
638 - Fix package publication with pnpm.
640 ## [2.4.0-1] - 2023-04-03
644 - Add `LESS_BUSY` worker choice strategy.
648 - Optimize worker storage in pool.
649 - Optimize worker alive status check.
650 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
651 - Optimize `LESS_USED` worker choice strategy.
655 - Ensure trimmable characters are checked at pool initialization.
656 - Fix message id integer overflow.
657 - Fix pool worker removal in worker choice strategy internals.
659 ## [2.4.0-0] - 2023-04-03
663 - Add `LESS_BUSY` worker choice strategy.
667 - Optimize worker storage in pool.
668 - Optimize worker alive status check.
669 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
670 - Optimize `LESS_USED` worker choice strategy.
674 - Ensure trimmable characters are checked at pool initialization.
675 - Fix message id integer overflow.
676 - Fix pool worker removal in worker choice strategy internals.
678 ## [2.3.10] - 2023-03-18
682 - Fix package.json `exports` syntax for ESM and CommonJS.
686 - Permit SemVer pre-release publication.
688 ## [2.3.10-2] - 2023-03-18
692 - Fix package.json `exports` syntax for ESM and CommonJS.
694 ## [2.3.10-1] - 2023-03-18
698 - Permit SemVer pre-release publication.
700 ## [2.3.10-0] - 2023-03-18
704 - Fix package.json `exports` syntax for ESM and CommonJS.
706 ## [2.3.9] - 2023-03-18
710 - Introduce ESM module support along with CommonJS one.
714 - Fix brown paper bag bug referencing the same object literal.
716 ## [2.3.8] - 2023-03-18
720 - Switch internal benchmarking code to benny.
721 - Switch to TypeScript 5.x.x.
722 - Switch rollup bundler plugins to core ones.
723 - Switch to TSDoc syntax.
724 - Enforce conventional commits.
728 - Fix random integer generator.
729 - Fix worker choice strategy pool type identification at initialization.
731 ## [2.3.7] - 2022-10-23
735 - Switch to open collective FOSS project funding platform.
736 - Switch to ts-standard linter configuration on TypeScript code.
740 - Fixed missing async on pool execute method.
741 - Fixed typing in TypeScript example.
742 - Fixed types in unit tests.
744 ## [2.3.6] - 2022-10-22
748 - Cleanup pool attributes and methods.
749 - Refine error types thrown.
753 - Fix continuous integration build on windows.
754 - Fix code coverage reporting by using c8 instead of nyc.
756 ## [2.3.5] - 2022-10-21
760 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
761 - Optimize tasks usage lookup implementation.
765 - Fix missed pool event emitter type export.
766 - Fix typedoc documentation generation.
768 ## [2.3.4] - 2022-10-17
772 - Fully automate release process with release-it.
776 - Optimize fair share task scheduling algorithm implementation.
777 - Update benchmarks versus external pools results with latest version.
779 ## [2.3.3] - 2022-10-15
783 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
785 ## [2.3.2] - 2022-10-14
789 - Optimize fair share worker selection strategy implementation.
793 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
795 ## [2.3.1] - 2022-10-13
799 - Pool worker choice strategies:
800 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
801 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
803 ## [2.2.2] - 2022-10-09
807 - Fixed `README.md` file.
809 ## [2.2.1] - 2022-10-08
813 - Dynamic worker choice strategy change at runtime.
815 ## [2.2.0] - 2022-01-05
819 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
821 ## [2.1.0] - 2021-08-29
825 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
829 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
830 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
831 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
832 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
834 ## [2.0.2] - 2021-05-12
838 - Fix `busy` event emission on fixed pool type
840 ## [2.0.1] - 2021-03-16
844 - Check if pool options are properly set.
845 - `busy` event is emitted on all pool types.
847 ## [2.0.0] - 2021-03-01
851 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
855 - `FullPool` event is now renamed to `busy`.
856 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
857 _Find more details on our JSDoc._
859 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
861 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
863 ### Pool options types declaration merge
865 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
867 #### New `export` strategy
871 const DynamicThreadPool = require('poolifier/lib/dynamic')
873 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
876 But you should always prefer just using
879 const { DynamicThreadPool } = require('poolifier')
882 #### New type definitions for input data and response
884 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
885 _This is not a limitation by poolifier but Node.js._
887 #### Public property replacements
889 `numWorkers` property is now `numberOfWorkers`
891 #### Internal (protected) properties and methods renaming
893 These properties are not intended for end users
895 - `id` => `nextMessageId`
897 These methods are not intended for end users
899 - `_chooseWorker` => `chooseWorker`
900 - `_newWorker` => `createWorker`
901 - `_execute` => `internalExecute`
902 - `_chooseWorker` => `chooseWorker`
903 - `_checkAlive` => `checkAlive`
905 - `_runAsync` => `runAsync`
907 ## [1.1.0] - 2020-05-21
911 - ThreadWorker support async functions as option
912 - Various external library patches
914 ## [1.0.0] - 2020-01-24
918 - FixedThreadPool implementation
919 - DynamicThreadPool implementation
920 - WorkerThread implementation to improve developer experience