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 - Avoid cascading tasks stealing under back pressure.
16 - Add fastpath to queued tasks rescheduling.
18 ## [2.6.33] - 2023-08-24
22 - Fix queued tasks rescheduling.
26 - Rename tasks queue options `queueMaxSize` to `size`.
30 - Task stealing scheduling algorithm if tasks queueing is enabled.
32 ## [2.6.32] - 2023-08-23
36 - Ensure no task can be executed when the pool is destroyed.
40 - Add `queueMaxSize` option to tasks queue options.
41 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
42 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
44 ## [2.6.31] - 2023-08-20
48 - Fix worker choice strategy retries mechanism in some edge cases.
52 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
53 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
55 ## [2.6.30] - 2023-08-19
59 - Ensure pool event `backPressure` is emitted.
60 - Ensure pool event `full` is emitted only once.
61 - Ensure worker node cannot be instantiated without proper arguments.
63 ## [2.6.29] - 2023-08-18
67 - Fix race condition between ready and task functions worker message handling at startup.
68 - Fix duplicate task function worker usage statistics computation per task function.
69 - Update task function worker usage statistics if and only if there's at least two different task functions.
70 - Fix race condition at task function worker usage executing task computation leading to negative value.
74 - 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).
75 - Use back pressure detection in worker choice strategies.
76 - Add worker choice strategies retries mechanism if no worker is eligible.
78 ## [2.6.28] - 2023-08-16
82 - Ensure pool workers are properly initialized.
86 - HTTP server pool examples: express-cluster, express-hybrid.
90 - Remove now useless branching in worker hot code path.
92 ## [2.6.27] - 2023-08-15
96 - Add `KillHandler` type definition to exported types.
100 - Add `destroy` event to pool API.
102 ## [2.6.26] - 2023-08-15
106 - Add kill handler to worker options allowing to execute custom code when worker is killed.
107 - Add `listTaskFunctions()` method to pool API.
108 - SMTP server pool example: nodemailer.
110 ## [2.6.25] - 2023-08-13
114 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
115 - WebSocket server pool examples: ws-cluster, ws-hybrid.
117 ## [2.6.24] - 2023-08-12
121 - Add array of transferable objects to the `execute()` method arguments.
122 - WebSocket server pool examples: ws-worker_threads.
124 ## [2.6.23] - 2023-08-11
128 - 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.
132 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
133 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
135 ## [2.6.22] - 2023-08-10
139 - Add missing `types` field to package.json `exports`.
143 - Structure markdown documentation (PR #811).
145 ## [2.6.21] - 2023-08-03
149 - Improve code documentation.
150 - Code refactoring and cleanup for better maintainability and readability.
152 ## [2.6.20] - 2023-07-21
156 - Fix queued tasks redistribution on error task execution starvation.
157 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
161 - Drastically reduce lookups by worker in the worker nodes.
163 ## [2.6.19] - 2023-07-20
167 - Dedicated internal communication channel for worker_threads pools.
169 ## [2.6.18] - 2023-07-19
173 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
175 ## [2.6.17] - 2023-07-16
179 - Add `listTaskFunctions()` method to worker API.
181 ## [2.6.16] - 2023-07-12
185 - Fix pool startup detection.
186 - Fix worker task functions handling.
188 ## [2.6.15] - 2023-07-11
192 - Take into account worker node readiness in worker choice strategies.
194 ## [2.6.14] - 2023-07-10
198 - Fix task function statistics tracking.
200 ## [2.6.13] - 2023-07-10
204 - Add per task function statistics tracking.
205 - Add public methods to manipulate the worker task functions at runtime.
207 ## [2.6.12] - 2023-07-09
211 - Workaround import issue with `node:os` module in node 16.x.x.
213 ## [2.6.11] - 2023-07-09
217 - Fix pool readiness semantic.
219 ## [2.6.10] - 2023-07-08
223 - Ensure workers are not recreated on error at pool startup.
227 - Add `ready` and `strategy` fields to pool information.
228 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
229 - Add dynamic pool sizing checks.
231 ## [2.6.9] - 2023-07-07
235 - Recreate the right worker type on uncaught exception.
239 - Add minimum and maximum to internal measurement statistics.
240 - Add `runTime` and `waitTime` to pool information.
241 - Check worker inactive time only on dynamic worker.
243 ## [2.6.8] - 2023-07-03
247 - Brown paper bag release to fix version handling in pool information.
249 ## [2.6.7] - 2023-07-03
253 - Ensure worker queued tasks at error are reassigned to other pool workers.
257 - Add pool `utilization` ratio to pool information.
258 - Add `version` to pool information.
259 - Add worker information to worker nodes.
261 ## [2.6.6] - 2023-07-01
265 - Add safe helper `availableParallelism()` to help sizing the pool.
269 - Ensure message handler is only registered in worker.
271 ## [2.6.5] - 2023-06-27
275 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
279 - Artificial version bump to 2.6.5 to workaround publication issue.
280 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
281 - Ensure pool event is emitted before task error promise rejection.
282 - Fix queued tasks count computation.
286 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
288 ## [2.6.4] - 2023-06-27
292 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
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 ## [2.6.3] - 2023-06-19
308 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
309 - Update strategies internals after statistics computation.
313 - Optimize O(1) queue implementation.
315 ## [2.6.2] - 2023-06-12
319 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
321 ## [2.6.1] - 2023-06-10
325 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
329 - Fix average statistics computation: ensure failed tasks are not accounted.
331 ## [2.6.0] - 2023-06-09
335 - Add `LEAST_ELU` worker choice strategy (experimental).
336 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
340 - Refactor pool worker node usage internals.
341 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
342 - Breaking change: pool information `info` property object fields have been renamed.
346 - Fix wait time accounting.
347 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
348 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
350 ## [2.5.4] - 2023-06-07
354 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
358 - Compute statistics at the worker level only if needed.
359 - Add `worker_threads` options to thread pool options.
363 - Make the `LEAST_BUSY` strategy only relies on task runtime.
365 ## [2.5.3] - 2023-06-04
369 - Refine pool information content.
370 - Limit pool internals public exposure.
372 ## [2.5.2] - 2023-06-02
376 - Add `taskError` pool event for task execution error.
377 - Add pool information `info` property to pool.
378 - Emit pool information on `busy` and `full` pool events.
380 ## [2.5.1] - 2023-06-01
384 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
385 - Add `error` pool event for uncaught worker error.
387 ## [2.5.0] - 2023-05-31
391 - Switch pool event emitter to `EventEmitterAsyncResource`.
392 - Add tasks wait time accounting in per worker tasks usage.
393 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
397 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
399 ## [2.4.14] - 2023-05-09
403 - Ensure no undefined task runtime can land in the tasks history.
404 - Fix median computation implementation once again.
408 - Unit tests for median and queue implementations.
410 ## [2.4.13] - 2023-05-08
414 - Fix worker choice strategy options validation.
415 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
417 ## [2.4.12] - 2023-05-06
421 - Support multiple task functions per worker.
422 - Add custom worker weights support to worker choice strategies options.
426 - Use O(1) queue implementation for tasks queueing.
430 - Fix median computation implementation.
431 - Fix fair share worker choice strategy internals update.
433 ## [2.4.11] - 2023-04-23
437 - Optimize free worker finding in worker choice strategies.
439 ## [2.4.10] - 2023-04-15
443 - Fix typescript type definition for task function: ensure the input data is optional.
444 - Fix typescript type definition for pool execute(): ensure the input data is optional.
446 ## [2.4.9] - 2023-04-15
450 - Add tasks queue enablement runtime setter to pool.
451 - Add tasks queue options runtime setter to pool.
452 - Add worker choice strategy options runtime setter to pool.
456 - Remove the tasks queuing experimental status.
460 - Fix task function type definition and validation.
461 - Fix worker choice strategy options handling.
463 ## [2.4.8] - 2023-04-12
467 - Fix message between main worker and worker type definition for tasks.
468 - Fix code documentation.
470 ## [2.4.7] - 2023-04-11
474 - Add worker tasks queue options to pool options.
478 - Fix missing documentation.
480 ## [2.4.6] - 2023-04-10
484 - Ensure one task at a time is executed per worker with tasks queueing enabled.
485 - Properly count worker executing tasks with tasks queueing enabled.
487 ## [2.4.5] - 2023-04-09
491 - Use monotonic high resolution timer for worker tasks runtime.
492 - Add worker tasks median runtime to statistics.
493 - Add worker tasks queue (experimental).
495 ## [2.4.4] - 2023-04-07
499 - Add `PoolEvents` enumeration and `PoolEvent` type.
503 - Destroy worker only on alive check.
505 ## [2.4.3] - 2023-04-07
509 - Fix typedoc generation with inheritance.
511 ## [2.4.2] - 2023-04-06
515 - Add `full` event to dynamic pool.
516 - Keep worker choice strategy in memory for conditional reuse.
520 - Fix possible negative worker key at worker removal in worker choice strategies.
522 ## [2.4.1] - 2023-04-05
526 - Optimize worker choice strategy for dynamic pool.
530 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
532 ## [2.4.0] - 2023-04-04
536 - Add `LESS_BUSY` worker choice strategy.
540 - Optimize worker storage in pool.
541 - Optimize worker alive status check.
542 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
543 - Optimize `LESS_USED` worker choice strategy.
544 - Update benchmarks versus external threads pools.
545 - Optimize tasks usage statistics requirements for worker choice strategy.
549 - Ensure trimmable characters are checked at pool initialization.
550 - Fix message id integer overflow.
551 - Fix pool worker removal in worker choice strategy internals.
552 - Fix package publication with pnpm.
554 ## [2.4.0-3] - 2023-04-04
558 - Add `LESS_BUSY` worker choice strategy.
562 - Optimize worker storage in pool.
563 - Optimize worker alive status check.
564 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
565 - Optimize `LESS_USED` worker choice strategy.
566 - Update benchmarks versus external threads pools.
570 - Ensure trimmable characters are checked at pool initialization.
571 - Fix message id integer overflow.
572 - Fix pool worker removal in worker choice strategy internals.
573 - Fix package publication with pnpm.
575 ## [2.4.0-2] - 2023-04-03
579 - Add `LESS_BUSY` worker choice strategy.
583 - Optimize worker storage in pool.
584 - Optimize worker alive status check.
585 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
586 - Optimize `LESS_USED` worker choice strategy.
590 - Ensure trimmable characters are checked at pool initialization.
591 - Fix message id integer overflow.
592 - Fix pool worker removal in worker choice strategy internals.
593 - Fix package publication with pnpm.
595 ## [2.4.0-1] - 2023-04-03
599 - Add `LESS_BUSY` worker choice strategy.
603 - Optimize worker storage in pool.
604 - Optimize worker alive status check.
605 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
606 - Optimize `LESS_USED` 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.
614 ## [2.4.0-0] - 2023-04-03
618 - Add `LESS_BUSY` worker choice strategy.
622 - Optimize worker storage in pool.
623 - Optimize worker alive status check.
624 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
625 - Optimize `LESS_USED` worker choice strategy.
629 - Ensure trimmable characters are checked at pool initialization.
630 - Fix message id integer overflow.
631 - Fix pool worker removal in worker choice strategy internals.
633 ## [2.3.10] - 2023-03-18
637 - Fix package.json `exports` syntax for ESM and CommonJS.
641 - Permit SemVer pre-release publication.
643 ## [2.3.10-2] - 2023-03-18
647 - Fix package.json `exports` syntax for ESM and CommonJS.
649 ## [2.3.10-1] - 2023-03-18
653 - Permit SemVer pre-release publication.
655 ## [2.3.10-0] - 2023-03-18
659 - Fix package.json `exports` syntax for ESM and CommonJS.
661 ## [2.3.9] - 2023-03-18
665 - Introduce ESM module support along with CommonJS one.
669 - Fix brown paper bag bug referencing the same object literal.
671 ## [2.3.8] - 2023-03-18
675 - Switch internal benchmarking code to benny.
676 - Switch to TypeScript 5.x.x.
677 - Switch rollup bundler plugins to core ones.
678 - Switch to TSDoc syntax.
679 - Enforce conventional commits.
683 - Fix random integer generator.
684 - Fix worker choice strategy pool type identification at initialization.
686 ## [2.3.7] - 2022-10-23
690 - Switch to open collective FOSS project funding platform.
691 - Switch to ts-standard linter configuration on TypeScript code.
695 - Fixed missing async on pool execute method.
696 - Fixed typing in TypeScript example.
697 - Fixed types in unit tests.
699 ## [2.3.6] - 2022-10-22
703 - Cleanup pool attributes and methods.
704 - Refine error types thrown.
708 - Fix continuous integration build on windows.
709 - Fix code coverage reporting by using c8 instead of nyc.
711 ## [2.3.5] - 2022-10-21
715 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
716 - Optimize tasks usage lookup implementation.
720 - Fix missed pool event emitter type export.
721 - Fix typedoc documentation generation.
723 ## [2.3.4] - 2022-10-17
727 - Fully automate release process with release-it.
731 - Optimize fair share task scheduling algorithm implementation.
732 - Update benchmarks versus external pools results with latest version.
734 ## [2.3.3] - 2022-10-15
738 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
740 ## [2.3.2] - 2022-10-14
744 - Optimize fair share worker selection strategy implementation.
748 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
750 ## [2.3.1] - 2022-10-13
754 - Pool worker choice strategies:
755 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
756 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
758 ## [2.2.2] - 2022-10-09
762 - Fixed `README.md` file.
764 ## [2.2.1] - 2022-10-08
768 - Dynamic worker choice strategy change at runtime.
770 ## [2.2.0] - 2022-01-05
774 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
776 ## [2.1.0] - 2021-08-29
780 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
784 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
785 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
786 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
787 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
789 ## [2.0.2] - 2021-05-12
793 - Fix `busy` event emission on fixed pool type
795 ## [2.0.1] - 2021-03-16
799 - Check if pool options are properly set.
800 - `busy` event is emitted on all pool types.
802 ## [2.0.0] - 2021-03-01
806 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
810 - `FullPool` event is now renamed to `busy`.
811 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
812 _Find more details on our JSDoc._
814 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
816 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
818 ### Pool options types declaration merge
820 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
822 #### New `export` strategy
826 const DynamicThreadPool = require('poolifier/lib/dynamic')
828 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
831 But you should always prefer just using
834 const { DynamicThreadPool } = require('poolifier')
837 #### New type definitions for input data and response
839 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
840 _This is not a limitation by poolifier but Node.js._
842 #### Public property replacements
844 `numWorkers` property is now `numberOfWorkers`
846 #### Internal (protected) properties and methods renaming
848 These properties are not intended for end users
850 - `id` => `nextMessageId`
852 These methods are not intended for end users
854 - `_chooseWorker` => `chooseWorker`
855 - `_newWorker` => `createWorker`
856 - `_execute` => `internalExecute`
857 - `_chooseWorker` => `chooseWorker`
858 - `_checkAlive` => `checkAlive`
860 - `_runAsync` => `runAsync`
862 ## [1.1.0] - 2020-05-21
866 - ThreadWorker support async functions as option
867 - Various external library patches
869 ## [1.0.0] - 2020-01-24
873 - FixedThreadPool implementation
874 - DynamicThreadPool implementation
875 - WorkerThread implementation to improve developer experience