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 - Don't account worker usage statistics for tasks that have failed.
13 - Fix pool information runtime and wait time median computation.
17 - Update simple moving average implementation to use a circular buffer.
18 - Update simple moving median implementation to use a circular buffer.
22 - Support for continuous tasks stealing.
24 ## [2.6.34] - 2023-08-24
28 - Avoid cascading tasks stealing under back pressure.
32 - Add fastpath to queued tasks rescheduling.
34 ## [2.6.33] - 2023-08-24
38 - Fix queued tasks rescheduling.
42 - Rename tasks queue options `queueMaxSize` to `size`.
46 - Task stealing scheduling algorithm if tasks queueing is enabled.
48 ## [2.6.32] - 2023-08-23
52 - Ensure no task can be executed when the pool is destroyed.
56 - Add `queueMaxSize` option to tasks queue options.
57 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
58 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
60 ## [2.6.31] - 2023-08-20
64 - Fix worker choice strategy retries mechanism in some edge cases.
68 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
69 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
71 ## [2.6.30] - 2023-08-19
75 - Ensure pool event `backPressure` is emitted.
76 - Ensure pool event `full` is emitted only once.
77 - Ensure worker node cannot be instantiated without proper arguments.
79 ## [2.6.29] - 2023-08-18
83 - Fix race condition between ready and task functions worker message handling at startup.
84 - Fix duplicate task function worker usage statistics computation per task function.
85 - Update task function worker usage statistics if and only if there's at least two different task functions.
86 - Fix race condition at task function worker usage executing task computation leading to negative value.
90 - 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).
91 - Use back pressure detection in worker choice strategies.
92 - Add worker choice strategies retries mechanism if no worker is eligible.
94 ## [2.6.28] - 2023-08-16
98 - Ensure pool workers are properly initialized.
102 - HTTP server pool examples: express-cluster, express-hybrid.
106 - Remove now useless branching in worker hot code path.
108 ## [2.6.27] - 2023-08-15
112 - Add `KillHandler` type definition to exported types.
116 - Add `destroy` event to pool API.
118 ## [2.6.26] - 2023-08-15
122 - Add kill handler to worker options allowing to execute custom code when worker is killed.
123 - Add `listTaskFunctions()` method to pool API.
124 - SMTP server pool example: nodemailer.
126 ## [2.6.25] - 2023-08-13
130 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
131 - WebSocket server pool examples: ws-cluster, ws-hybrid.
133 ## [2.6.24] - 2023-08-12
137 - Add array of transferable objects to the `execute()` method arguments.
138 - WebSocket server pool examples: ws-worker_threads.
140 ## [2.6.23] - 2023-08-11
144 - 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.
148 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
149 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
151 ## [2.6.22] - 2023-08-10
155 - Add missing `types` field to package.json `exports`.
159 - Structure markdown documentation (PR #811).
161 ## [2.6.21] - 2023-08-03
165 - Improve code documentation.
166 - Code refactoring and cleanup for better maintainability and readability.
168 ## [2.6.20] - 2023-07-21
172 - Fix queued tasks redistribution on error task execution starvation.
173 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
177 - Drastically reduce lookups by worker in the worker nodes.
179 ## [2.6.19] - 2023-07-20
183 - Dedicated internal communication channel for worker_threads pools.
185 ## [2.6.18] - 2023-07-19
189 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
191 ## [2.6.17] - 2023-07-16
195 - Add `listTaskFunctions()` method to worker API.
197 ## [2.6.16] - 2023-07-12
201 - Fix pool startup detection.
202 - Fix worker task functions handling.
204 ## [2.6.15] - 2023-07-11
208 - Take into account worker node readiness in worker choice strategies.
210 ## [2.6.14] - 2023-07-10
214 - Fix task function statistics tracking.
216 ## [2.6.13] - 2023-07-10
220 - Add per task function statistics tracking.
221 - Add public methods to manipulate the worker task functions at runtime.
223 ## [2.6.12] - 2023-07-09
227 - Workaround import issue with `node:os` module in node 16.x.x.
229 ## [2.6.11] - 2023-07-09
233 - Fix pool readiness semantic.
235 ## [2.6.10] - 2023-07-08
239 - Ensure workers are not recreated on error at pool startup.
243 - Add `ready` and `strategy` fields to pool information.
244 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
245 - Add dynamic pool sizing checks.
247 ## [2.6.9] - 2023-07-07
251 - Recreate the right worker type on uncaught exception.
255 - Add minimum and maximum to internal measurement statistics.
256 - Add `runTime` and `waitTime` to pool information.
257 - Check worker inactive time only on dynamic worker.
259 ## [2.6.8] - 2023-07-03
263 - Brown paper bag release to fix version handling in pool information.
265 ## [2.6.7] - 2023-07-03
269 - Ensure worker queued tasks at error are reassigned to other pool workers.
273 - Add pool `utilization` ratio to pool information.
274 - Add `version` to pool information.
275 - Add worker information to worker nodes.
277 ## [2.6.6] - 2023-07-01
281 - Add safe helper `availableParallelism()` to help sizing the pool.
285 - Ensure message handler is only registered in worker.
287 ## [2.6.5] - 2023-06-27
291 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
295 - Artificial version bump to 2.6.5 to workaround publication issue.
296 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
297 - Ensure pool event is emitted before task error promise rejection.
298 - Fix queued tasks count computation.
302 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
304 ## [2.6.4] - 2023-06-27
308 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
312 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
313 - Ensure pool event is emitted before task error promise rejection.
314 - Fix queued tasks count computation.
318 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
320 ## [2.6.3] - 2023-06-19
324 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
325 - Update strategies internals after statistics computation.
329 - Optimize O(1) queue implementation.
331 ## [2.6.2] - 2023-06-12
335 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
337 ## [2.6.1] - 2023-06-10
341 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
345 - Fix average statistics computation: ensure failed tasks are not accounted.
347 ## [2.6.0] - 2023-06-09
351 - Add `LEAST_ELU` worker choice strategy (experimental).
352 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
356 - Refactor pool worker node usage internals.
357 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
358 - Breaking change: pool information `info` property object fields have been renamed.
362 - Fix wait time accounting.
363 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
364 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
366 ## [2.5.4] - 2023-06-07
370 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
374 - Compute statistics at the worker level only if needed.
375 - Add `worker_threads` options to thread pool options.
379 - Make the `LEAST_BUSY` strategy only relies on task runtime.
381 ## [2.5.3] - 2023-06-04
385 - Refine pool information content.
386 - Limit pool internals public exposure.
388 ## [2.5.2] - 2023-06-02
392 - Add `taskError` pool event for task execution error.
393 - Add pool information `info` property to pool.
394 - Emit pool information on `busy` and `full` pool events.
396 ## [2.5.1] - 2023-06-01
400 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
401 - Add `error` pool event for uncaught worker error.
403 ## [2.5.0] - 2023-05-31
407 - Switch pool event emitter to `EventEmitterAsyncResource`.
408 - Add tasks wait time accounting in per worker tasks usage.
409 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
413 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
415 ## [2.4.14] - 2023-05-09
419 - Ensure no undefined task runtime can land in the tasks history.
420 - Fix median computation implementation once again.
424 - Unit tests for median and queue implementations.
426 ## [2.4.13] - 2023-05-08
430 - Fix worker choice strategy options validation.
431 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
433 ## [2.4.12] - 2023-05-06
437 - Support multiple task functions per worker.
438 - Add custom worker weights support to worker choice strategies options.
442 - Use O(1) queue implementation for tasks queueing.
446 - Fix median computation implementation.
447 - Fix fair share worker choice strategy internals update.
449 ## [2.4.11] - 2023-04-23
453 - Optimize free worker finding in worker choice strategies.
455 ## [2.4.10] - 2023-04-15
459 - Fix typescript type definition for task function: ensure the input data is optional.
460 - Fix typescript type definition for pool execute(): ensure the input data is optional.
462 ## [2.4.9] - 2023-04-15
466 - Add tasks queue enablement runtime setter to pool.
467 - Add tasks queue options runtime setter to pool.
468 - Add worker choice strategy options runtime setter to pool.
472 - Remove the tasks queuing experimental status.
476 - Fix task function type definition and validation.
477 - Fix worker choice strategy options handling.
479 ## [2.4.8] - 2023-04-12
483 - Fix message between main worker and worker type definition for tasks.
484 - Fix code documentation.
486 ## [2.4.7] - 2023-04-11
490 - Add worker tasks queue options to pool options.
494 - Fix missing documentation.
496 ## [2.4.6] - 2023-04-10
500 - Ensure one task at a time is executed per worker with tasks queueing enabled.
501 - Properly count worker executing tasks with tasks queueing enabled.
503 ## [2.4.5] - 2023-04-09
507 - Use monotonic high resolution timer for worker tasks runtime.
508 - Add worker tasks median runtime to statistics.
509 - Add worker tasks queue (experimental).
511 ## [2.4.4] - 2023-04-07
515 - Add `PoolEvents` enumeration and `PoolEvent` type.
519 - Destroy worker only on alive check.
521 ## [2.4.3] - 2023-04-07
525 - Fix typedoc generation with inheritance.
527 ## [2.4.2] - 2023-04-06
531 - Add `full` event to dynamic pool.
532 - Keep worker choice strategy in memory for conditional reuse.
536 - Fix possible negative worker key at worker removal in worker choice strategies.
538 ## [2.4.1] - 2023-04-05
542 - Optimize worker choice strategy for dynamic pool.
546 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
548 ## [2.4.0] - 2023-04-04
552 - Add `LESS_BUSY` worker choice strategy.
556 - Optimize worker storage in pool.
557 - Optimize worker alive status check.
558 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
559 - Optimize `LESS_USED` worker choice strategy.
560 - Update benchmarks versus external threads pools.
561 - Optimize tasks usage statistics requirements for worker choice strategy.
565 - Ensure trimmable characters are checked at pool initialization.
566 - Fix message id integer overflow.
567 - Fix pool worker removal in worker choice strategy internals.
568 - Fix package publication with pnpm.
570 ## [2.4.0-3] - 2023-04-04
574 - Add `LESS_BUSY` worker choice strategy.
578 - Optimize worker storage in pool.
579 - Optimize worker alive status check.
580 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
581 - Optimize `LESS_USED` worker choice strategy.
582 - Update benchmarks versus external threads pools.
586 - Ensure trimmable characters are checked at pool initialization.
587 - Fix message id integer overflow.
588 - Fix pool worker removal in worker choice strategy internals.
589 - Fix package publication with pnpm.
591 ## [2.4.0-2] - 2023-04-03
595 - Add `LESS_BUSY` worker choice strategy.
599 - Optimize worker storage in pool.
600 - Optimize worker alive status check.
601 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
602 - Optimize `LESS_USED` worker choice strategy.
606 - Ensure trimmable characters are checked at pool initialization.
607 - Fix message id integer overflow.
608 - Fix pool worker removal in worker choice strategy internals.
609 - Fix package publication with pnpm.
611 ## [2.4.0-1] - 2023-04-03
615 - Add `LESS_BUSY` worker choice strategy.
619 - Optimize worker storage in pool.
620 - Optimize worker alive status check.
621 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
622 - Optimize `LESS_USED` worker choice strategy.
626 - Ensure trimmable characters are checked at pool initialization.
627 - Fix message id integer overflow.
628 - Fix pool worker removal in worker choice strategy internals.
630 ## [2.4.0-0] - 2023-04-03
634 - Add `LESS_BUSY` worker choice strategy.
638 - Optimize worker storage in pool.
639 - Optimize worker alive status check.
640 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
641 - Optimize `LESS_USED` worker choice strategy.
645 - Ensure trimmable characters are checked at pool initialization.
646 - Fix message id integer overflow.
647 - Fix pool worker removal in worker choice strategy internals.
649 ## [2.3.10] - 2023-03-18
653 - Fix package.json `exports` syntax for ESM and CommonJS.
657 - Permit SemVer pre-release publication.
659 ## [2.3.10-2] - 2023-03-18
663 - Fix package.json `exports` syntax for ESM and CommonJS.
665 ## [2.3.10-1] - 2023-03-18
669 - Permit SemVer pre-release publication.
671 ## [2.3.10-0] - 2023-03-18
675 - Fix package.json `exports` syntax for ESM and CommonJS.
677 ## [2.3.9] - 2023-03-18
681 - Introduce ESM module support along with CommonJS one.
685 - Fix brown paper bag bug referencing the same object literal.
687 ## [2.3.8] - 2023-03-18
691 - Switch internal benchmarking code to benny.
692 - Switch to TypeScript 5.x.x.
693 - Switch rollup bundler plugins to core ones.
694 - Switch to TSDoc syntax.
695 - Enforce conventional commits.
699 - Fix random integer generator.
700 - Fix worker choice strategy pool type identification at initialization.
702 ## [2.3.7] - 2022-10-23
706 - Switch to open collective FOSS project funding platform.
707 - Switch to ts-standard linter configuration on TypeScript code.
711 - Fixed missing async on pool execute method.
712 - Fixed typing in TypeScript example.
713 - Fixed types in unit tests.
715 ## [2.3.6] - 2022-10-22
719 - Cleanup pool attributes and methods.
720 - Refine error types thrown.
724 - Fix continuous integration build on windows.
725 - Fix code coverage reporting by using c8 instead of nyc.
727 ## [2.3.5] - 2022-10-21
731 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
732 - Optimize tasks usage lookup implementation.
736 - Fix missed pool event emitter type export.
737 - Fix typedoc documentation generation.
739 ## [2.3.4] - 2022-10-17
743 - Fully automate release process with release-it.
747 - Optimize fair share task scheduling algorithm implementation.
748 - Update benchmarks versus external pools results with latest version.
750 ## [2.3.3] - 2022-10-15
754 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
756 ## [2.3.2] - 2022-10-14
760 - Optimize fair share worker selection strategy implementation.
764 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
766 ## [2.3.1] - 2022-10-13
770 - Pool worker choice strategies:
771 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
772 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
774 ## [2.2.2] - 2022-10-09
778 - Fixed `README.md` file.
780 ## [2.2.1] - 2022-10-08
784 - Dynamic worker choice strategy change at runtime.
786 ## [2.2.0] - 2022-01-05
790 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
792 ## [2.1.0] - 2021-08-29
796 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
800 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
801 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
802 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
803 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
805 ## [2.0.2] - 2021-05-12
809 - Fix `busy` event emission on fixed pool type
811 ## [2.0.1] - 2021-03-16
815 - Check if pool options are properly set.
816 - `busy` event is emitted on all pool types.
818 ## [2.0.0] - 2021-03-01
822 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
826 - `FullPool` event is now renamed to `busy`.
827 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
828 _Find more details on our JSDoc._
830 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
832 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
834 ### Pool options types declaration merge
836 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
838 #### New `export` strategy
842 const DynamicThreadPool = require('poolifier/lib/dynamic')
844 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
847 But you should always prefer just using
850 const { DynamicThreadPool } = require('poolifier')
853 #### New type definitions for input data and response
855 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
856 _This is not a limitation by poolifier but Node.js._
858 #### Public property replacements
860 `numWorkers` property is now `numberOfWorkers`
862 #### Internal (protected) properties and methods renaming
864 These properties are not intended for end users
866 - `id` => `nextMessageId`
868 These methods are not intended for end users
870 - `_chooseWorker` => `chooseWorker`
871 - `_newWorker` => `createWorker`
872 - `_execute` => `internalExecute`
873 - `_chooseWorker` => `chooseWorker`
874 - `_checkAlive` => `checkAlive`
876 - `_runAsync` => `runAsync`
878 ## [1.1.0] - 2020-05-21
882 - ThreadWorker support async functions as option
883 - Various external library patches
885 ## [1.0.0] - 2020-01-24
889 - FixedThreadPool implementation
890 - DynamicThreadPool implementation
891 - WorkerThread implementation to improve developer experience