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 - Add `queueMaxSize` option to tasks queue options.
13 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
14 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
16 ## [2.6.31] - 2023-08-20
20 - Fix worker choice strategy retries mechanism in some edge cases.
24 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
25 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
27 ## [2.6.30] - 2023-08-19
31 - Ensure pool event `backPressure` is emitted.
32 - Ensure pool event `full` is emitted only once.
33 - Ensure worker node cannot be instantiated without proper arguments.
35 ## [2.6.29] - 2023-08-18
39 - Fix race condition between ready and task functions worker message handling at startup.
40 - Fix duplicate task function worker usage statistics computation per task function.
41 - Update task function worker usage statistics if and only if there's at least two different task functions.
42 - Fix race condition at task function worker usage executing task computation leading to negative value.
46 - 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).
47 - Use back pressure detection in worker choice strategies.
48 - Add worker choice strategies retries mechanism if no worker is eligible.
50 ## [2.6.28] - 2023-08-16
54 - Ensure pool workers are properly initialized.
58 - HTTP server pool examples: express-cluster, express-hybrid.
62 - Remove now useless branching in worker hot code path.
64 ## [2.6.27] - 2023-08-15
68 - Add `KillHandler` type definition to exported types.
72 - Add `destroy` event to pool API.
74 ## [2.6.26] - 2023-08-15
78 - Add kill handler to worker options allowing to execute custom code when worker is killed.
79 - Add `listTaskFunctions()` method to pool API.
80 - SMTP server pool example: nodemailer.
82 ## [2.6.25] - 2023-08-13
86 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
87 - WebSocket server pool examples: ws-cluster, ws-hybrid.
89 ## [2.6.24] - 2023-08-12
93 - Add array of transferable objects to the `execute()` method arguments.
94 - WebSocket server pool examples: ws-worker_threads.
96 ## [2.6.23] - 2023-08-11
100 - 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.
104 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
105 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
107 ## [2.6.22] - 2023-08-10
111 - Add missing `types` field to package.json `exports`.
115 - Structure markdown documentation (PR #811).
117 ## [2.6.21] - 2023-08-03
121 - Improve code documentation.
122 - Code refactoring and cleanup for better maintainability and readability.
124 ## [2.6.20] - 2023-07-21
128 - Fix queued tasks redistribution on error task execution starvation.
129 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
133 - Drastically reduce lookups by worker in the worker nodes.
135 ## [2.6.19] - 2023-07-20
139 - Dedicated internal communication channel for worker_threads pools.
141 ## [2.6.18] - 2023-07-19
145 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
147 ## [2.6.17] - 2023-07-16
151 - Add `listTaskFunctions()` method to worker API.
153 ## [2.6.16] - 2023-07-12
157 - Fix pool startup detection.
158 - Fix worker task functions handling.
160 ## [2.6.15] - 2023-07-11
164 - Take into account worker node readiness in worker choice strategies.
166 ## [2.6.14] - 2023-07-10
170 - Fix task function statistics tracking.
172 ## [2.6.13] - 2023-07-10
176 - Add per task function statistics tracking.
177 - Add public methods to manipulate the worker task functions at runtime.
179 ## [2.6.12] - 2023-07-09
183 - Workaround import issue with `node:os` module in node 16.x.x.
185 ## [2.6.11] - 2023-07-09
189 - Fix pool readiness semantic.
191 ## [2.6.10] - 2023-07-08
195 - Ensure workers are not recreated on error at pool startup.
199 - Add `ready` and `strategy` fields to pool information.
200 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
201 - Add dynamic pool sizing checks.
203 ## [2.6.9] - 2023-07-07
207 - Recreate the right worker type on uncaught exception.
211 - Add minimum and maximum to internal measurement statistics.
212 - Add `runTime` and `waitTime` to pool information.
213 - Check worker inactive time only on dynamic worker.
215 ## [2.6.8] - 2023-07-03
219 - Brown paper bag release to fix version handling in pool information.
221 ## [2.6.7] - 2023-07-03
225 - Ensure worker queued tasks at error are reassigned to other pool workers.
229 - Add pool `utilization` ratio to pool information.
230 - Add `version` to pool information.
231 - Add worker information to worker nodes.
233 ## [2.6.6] - 2023-07-01
237 - Add safe helper `availableParallelism()` to help sizing the pool.
241 - Ensure message handler is only registered in worker.
243 ## [2.6.5] - 2023-06-27
247 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
251 - Artificial version bump to 2.6.5 to workaround publication issue.
252 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
253 - Ensure pool event is emitted before task error promise rejection.
254 - Fix queued tasks count computation.
258 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
260 ## [2.6.4] - 2023-06-27
264 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
268 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
269 - Ensure pool event is emitted before task error promise rejection.
270 - Fix queued tasks count computation.
274 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
276 ## [2.6.3] - 2023-06-19
280 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
281 - Update strategies internals after statistics computation.
285 - Optimize O(1) queue implementation.
287 ## [2.6.2] - 2023-06-12
291 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
293 ## [2.6.1] - 2023-06-10
297 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
301 - Fix average statistics computation: ensure failed tasks are not accounted.
303 ## [2.6.0] - 2023-06-09
307 - Add `LEAST_ELU` worker choice strategy (experimental).
308 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
312 - Refactor pool worker node usage internals.
313 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
314 - Breaking change: pool information `info` property object fields have been renamed.
318 - Fix wait time accounting.
319 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
320 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
322 ## [2.5.4] - 2023-06-07
326 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
330 - Compute statistics at the worker level only if needed.
331 - Add `worker_threads` options to thread pool options.
335 - Make the `LEAST_BUSY` strategy only relies on task runtime.
337 ## [2.5.3] - 2023-06-04
341 - Refine pool information content.
342 - Limit pool internals public exposure.
344 ## [2.5.2] - 2023-06-02
348 - Add `taskError` pool event for task execution error.
349 - Add pool information `info` property to pool.
350 - Emit pool information on `busy` and `full` pool events.
352 ## [2.5.1] - 2023-06-01
356 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
357 - Add `error` pool event for uncaught worker error.
359 ## [2.5.0] - 2023-05-31
363 - Switch pool event emitter to `EventEmitterAsyncResource`.
364 - Add tasks wait time accounting in per worker tasks usage.
365 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
369 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
371 ## [2.4.14] - 2023-05-09
375 - Ensure no undefined task runtime can land in the tasks history.
376 - Fix median computation implementation once again.
380 - Unit tests for median and queue implementations.
382 ## [2.4.13] - 2023-05-08
386 - Fix worker choice strategy options validation.
387 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
389 ## [2.4.12] - 2023-05-06
393 - Support multiple task functions per worker.
394 - Add custom worker weights support to worker choice strategies options.
398 - Use O(1) queue implementation for tasks queueing.
402 - Fix median computation implementation.
403 - Fix fair share worker choice strategy internals update.
405 ## [2.4.11] - 2023-04-23
409 - Optimize free worker finding in worker choice strategies.
411 ## [2.4.10] - 2023-04-15
415 - Fix typescript type definition for task function: ensure the input data is optional.
416 - Fix typescript type definition for pool execute(): ensure the input data is optional.
418 ## [2.4.9] - 2023-04-15
422 - Add tasks queue enablement runtime setter to pool.
423 - Add tasks queue options runtime setter to pool.
424 - Add worker choice strategy options runtime setter to pool.
428 - Remove the tasks queuing experimental status.
432 - Fix task function type definition and validation.
433 - Fix worker choice strategy options handling.
435 ## [2.4.8] - 2023-04-12
439 - Fix message between main worker and worker type definition for tasks.
440 - Fix code documentation.
442 ## [2.4.7] - 2023-04-11
446 - Add worker tasks queue options to pool options.
450 - Fix missing documentation.
452 ## [2.4.6] - 2023-04-10
456 - Ensure one task at a time is executed per worker with tasks queueing enabled.
457 - Properly count worker executing tasks with tasks queueing enabled.
459 ## [2.4.5] - 2023-04-09
463 - Use monotonic high resolution timer for worker tasks runtime.
464 - Add worker tasks median runtime to statistics.
465 - Add worker tasks queue (experimental).
467 ## [2.4.4] - 2023-04-07
471 - Add `PoolEvents` enumeration and `PoolEvent` type.
475 - Destroy worker only on alive check.
477 ## [2.4.3] - 2023-04-07
481 - Fix typedoc generation with inheritance.
483 ## [2.4.2] - 2023-04-06
487 - Add `full` event to dynamic pool.
488 - Keep worker choice strategy in memory for conditional reuse.
492 - Fix possible negative worker key at worker removal in worker choice strategies.
494 ## [2.4.1] - 2023-04-05
498 - Optimize worker choice strategy for dynamic pool.
502 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
504 ## [2.4.0] - 2023-04-04
508 - Add `LESS_BUSY` worker choice strategy.
512 - Optimize worker storage in pool.
513 - Optimize worker alive status check.
514 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
515 - Optimize `LESS_USED` worker choice strategy.
516 - Update benchmarks versus external threads pools.
517 - Optimize tasks usage statistics requirements for worker choice strategy.
521 - Ensure trimmable characters are checked at pool initialization.
522 - Fix message id integer overflow.
523 - Fix pool worker removal in worker choice strategy internals.
524 - Fix package publication with pnpm.
526 ## [2.4.0-3] - 2023-04-04
530 - Add `LESS_BUSY` worker choice strategy.
534 - Optimize worker storage in pool.
535 - Optimize worker alive status check.
536 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
537 - Optimize `LESS_USED` worker choice strategy.
538 - Update benchmarks versus external threads pools.
542 - Ensure trimmable characters are checked at pool initialization.
543 - Fix message id integer overflow.
544 - Fix pool worker removal in worker choice strategy internals.
545 - Fix package publication with pnpm.
547 ## [2.4.0-2] - 2023-04-03
551 - Add `LESS_BUSY` worker choice strategy.
555 - Optimize worker storage in pool.
556 - Optimize worker alive status check.
557 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
558 - Optimize `LESS_USED` worker choice strategy.
562 - Ensure trimmable characters are checked at pool initialization.
563 - Fix message id integer overflow.
564 - Fix pool worker removal in worker choice strategy internals.
565 - Fix package publication with pnpm.
567 ## [2.4.0-1] - 2023-04-03
571 - Add `LESS_BUSY` worker choice strategy.
575 - Optimize worker storage in pool.
576 - Optimize worker alive status check.
577 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
578 - Optimize `LESS_USED` worker choice strategy.
582 - Ensure trimmable characters are checked at pool initialization.
583 - Fix message id integer overflow.
584 - Fix pool worker removal in worker choice strategy internals.
586 ## [2.4.0-0] - 2023-04-03
590 - Add `LESS_BUSY` worker choice strategy.
594 - Optimize worker storage in pool.
595 - Optimize worker alive status check.
596 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
597 - Optimize `LESS_USED` worker choice strategy.
601 - Ensure trimmable characters are checked at pool initialization.
602 - Fix message id integer overflow.
603 - Fix pool worker removal in worker choice strategy internals.
605 ## [2.3.10] - 2023-03-18
609 - Fix package.json `exports` syntax for ESM and CommonJS.
613 - Permit SemVer pre-release publication.
615 ## [2.3.10-2] - 2023-03-18
619 - Fix package.json `exports` syntax for ESM and CommonJS.
621 ## [2.3.10-1] - 2023-03-18
625 - Permit SemVer pre-release publication.
627 ## [2.3.10-0] - 2023-03-18
631 - Fix package.json `exports` syntax for ESM and CommonJS.
633 ## [2.3.9] - 2023-03-18
637 - Introduce ESM module support along with CommonJS one.
641 - Fix brown paper bag bug referencing the same object literal.
643 ## [2.3.8] - 2023-03-18
647 - Switch internal benchmarking code to benny.
648 - Switch to TypeScript 5.x.x.
649 - Switch rollup bundler plugins to core ones.
650 - Switch to TSDoc syntax.
651 - Enforce conventional commits.
655 - Fix random integer generator.
656 - Fix worker choice strategy pool type identification at initialization.
658 ## [2.3.7] - 2022-10-23
662 - Switch to open collective FOSS project funding platform.
663 - Switch to ts-standard linter configuration on TypeScript code.
667 - Fixed missing async on pool execute method.
668 - Fixed typing in TypeScript example.
669 - Fixed types in unit tests.
671 ## [2.3.6] - 2022-10-22
675 - Cleanup pool attributes and methods.
676 - Refine error types thrown.
680 - Fix continuous integration build on windows.
681 - Fix code coverage reporting by using c8 instead of nyc.
683 ## [2.3.5] - 2022-10-21
687 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
688 - Optimize tasks usage lookup implementation.
692 - Fix missed pool event emitter type export.
693 - Fix typedoc documentation generation.
695 ## [2.3.4] - 2022-10-17
699 - Fully automate release process with release-it.
703 - Optimize fair share task scheduling algorithm implementation.
704 - Update benchmarks versus external pools results with latest version.
706 ## [2.3.3] - 2022-10-15
710 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
712 ## [2.3.2] - 2022-10-14
716 - Optimize fair share worker selection strategy implementation.
720 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
722 ## [2.3.1] - 2022-10-13
726 - Pool worker choice strategies:
727 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
728 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
730 ## [2.2.2] - 2022-10-09
734 - Fixed `README.md` file.
736 ## [2.2.1] - 2022-10-08
740 - Dynamic worker choice strategy change at runtime.
742 ## [2.2.0] - 2022-01-05
746 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
748 ## [2.1.0] - 2021-08-29
752 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
756 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
757 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
758 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
759 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
761 ## [2.0.2] - 2021-05-12
765 - Fix `busy` event emission on fixed pool type
767 ## [2.0.1] - 2021-03-16
771 - Check if pool options are properly set.
772 - `busy` event is emitted on all pool types.
774 ## [2.0.0] - 2021-03-01
778 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
782 - `FullPool` event is now renamed to `busy`.
783 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
784 _Find more details on our JSDoc._
786 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
788 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
790 ### Pool options types declaration merge
792 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
794 #### New `export` strategy
798 const DynamicThreadPool = require('poolifier/lib/dynamic')
800 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
803 But you should always prefer just using
806 const { DynamicThreadPool } = require('poolifier')
809 #### New type definitions for input data and response
811 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
812 _This is not a limitation by poolifier but Node.js._
814 #### Public property replacements
816 `numWorkers` property is now `numberOfWorkers`
818 #### Internal (protected) properties and methods renaming
820 These properties are not intended for end users
822 - `id` => `nextMessageId`
824 These methods are not intended for end users
826 - `_chooseWorker` => `chooseWorker`
827 - `_newWorker` => `createWorker`
828 - `_execute` => `internalExecute`
829 - `_chooseWorker` => `chooseWorker`
830 - `_checkAlive` => `checkAlive`
832 - `_runAsync` => `runAsync`
834 ## [1.1.0] - 2020-05-21
838 - ThreadWorker support async functions as option
839 - Various external library patches
841 ## [1.0.0] - 2020-01-24
845 - FixedThreadPool implementation
846 - DynamicThreadPool implementation
847 - WorkerThread implementation to improve developer experience