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 - Ensure unused worker usage statistics are deleted at runtime.
16 - Rename worker choice strategy options `choiceRetries` to `retries`.
18 ## [2.6.36] - 2023-08-27
22 - Fix pool `execute()` arguments check.
26 - Make continuous tasks stealing algorithm less aggressive.
27 - Fine tune tasks stealing algorithm under back pressure.
29 ## [2.6.35] - 2023-08-25
33 - Don't account worker usage statistics for tasks that have failed.
34 - Fix pool information runtime and wait time median computation.
38 - Update simple moving average implementation to use a circular buffer.
39 - Update simple moving median implementation to use a circular buffer.
40 - Account for stolen tasks in worker usage statistics and pool information.
44 - Continuous tasks stealing algorithm.
46 ## [2.6.34] - 2023-08-24
50 - Avoid cascading tasks stealing under back pressure.
54 - Add fastpath to queued tasks rescheduling.
56 ## [2.6.33] - 2023-08-24
60 - Fix queued tasks rescheduling.
64 - Rename tasks queue options `queueMaxSize` to `size`.
68 - Task stealing scheduling algorithm if tasks queueing is enabled.
70 ## [2.6.32] - 2023-08-23
74 - Ensure no task can be executed when the pool is destroyed.
78 - Add `queueMaxSize` option to tasks queue options.
79 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
80 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
82 ## [2.6.31] - 2023-08-20
86 - Fix worker choice strategy retries mechanism in some edge cases.
90 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
91 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
93 ## [2.6.30] - 2023-08-19
97 - Ensure pool event `backPressure` is emitted.
98 - Ensure pool event `full` is emitted only once.
99 - Ensure worker node cannot be instantiated without proper arguments.
101 ## [2.6.29] - 2023-08-18
105 - Fix race condition between ready and task functions worker message handling at startup.
106 - Fix duplicate task function worker usage statistics computation per task function.
107 - Update task function worker usage statistics if and only if there's at least two different task functions.
108 - Fix race condition at task function worker usage executing task computation leading to negative value.
112 - 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).
113 - Use back pressure detection in worker choice strategies.
114 - Add worker choice strategies retries mechanism if no worker is eligible.
116 ## [2.6.28] - 2023-08-16
120 - Ensure pool workers are properly initialized.
124 - HTTP server pool examples: express-cluster, express-hybrid.
128 - Remove now useless branching in worker hot code path.
130 ## [2.6.27] - 2023-08-15
134 - Add `KillHandler` type definition to exported types.
138 - Add `destroy` event to pool API.
140 ## [2.6.26] - 2023-08-15
144 - Add kill handler to worker options allowing to execute custom code when worker is killed.
145 - Add `listTaskFunctions()` method to pool API.
146 - SMTP server pool example: nodemailer.
148 ## [2.6.25] - 2023-08-13
152 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
153 - WebSocket server pool examples: ws-cluster, ws-hybrid.
155 ## [2.6.24] - 2023-08-12
159 - Add array of transferable objects to the `execute()` method arguments.
160 - WebSocket server pool examples: ws-worker_threads.
162 ## [2.6.23] - 2023-08-11
166 - 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.
170 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
171 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
173 ## [2.6.22] - 2023-08-10
177 - Add missing `types` field to package.json `exports`.
181 - Structure markdown documentation (PR #811).
183 ## [2.6.21] - 2023-08-03
187 - Improve code documentation.
188 - Code refactoring and cleanup for better maintainability and readability.
190 ## [2.6.20] - 2023-07-21
194 - Fix queued tasks redistribution on error task execution starvation.
195 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
199 - Drastically reduce lookups by worker in the worker nodes.
201 ## [2.6.19] - 2023-07-20
205 - Dedicated internal communication channel for worker_threads pools.
207 ## [2.6.18] - 2023-07-19
211 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
213 ## [2.6.17] - 2023-07-16
217 - Add `listTaskFunctions()` method to worker API.
219 ## [2.6.16] - 2023-07-12
223 - Fix pool startup detection.
224 - Fix worker task functions handling.
226 ## [2.6.15] - 2023-07-11
230 - Take into account worker node readiness in worker choice strategies.
232 ## [2.6.14] - 2023-07-10
236 - Fix task function statistics tracking.
238 ## [2.6.13] - 2023-07-10
242 - Add per task function statistics tracking.
243 - Add public methods to manipulate the worker task functions at runtime.
245 ## [2.6.12] - 2023-07-09
249 - Workaround import issue with `node:os` module in node 16.x.x.
251 ## [2.6.11] - 2023-07-09
255 - Fix pool readiness semantic.
257 ## [2.6.10] - 2023-07-08
261 - Ensure workers are not recreated on error at pool startup.
265 - Add `ready` and `strategy` fields to pool information.
266 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
267 - Add dynamic pool sizing checks.
269 ## [2.6.9] - 2023-07-07
273 - Recreate the right worker type on uncaught exception.
277 - Add minimum and maximum to internal measurement statistics.
278 - Add `runTime` and `waitTime` to pool information.
279 - Check worker inactive time only on dynamic worker.
281 ## [2.6.8] - 2023-07-03
285 - Brown paper bag release to fix version handling in pool information.
287 ## [2.6.7] - 2023-07-03
291 - Ensure worker queued tasks at error are reassigned to other pool workers.
295 - Add pool `utilization` ratio to pool information.
296 - Add `version` to pool information.
297 - Add worker information to worker nodes.
299 ## [2.6.6] - 2023-07-01
303 - Add safe helper `availableParallelism()` to help sizing the pool.
307 - Ensure message handler is only registered in worker.
309 ## [2.6.5] - 2023-06-27
313 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
317 - Artificial version bump to 2.6.5 to workaround publication issue.
318 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
319 - Ensure pool event is emitted before task error promise rejection.
320 - Fix queued tasks count computation.
324 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
326 ## [2.6.4] - 2023-06-27
330 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
334 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
335 - Ensure pool event is emitted before task error promise rejection.
336 - Fix queued tasks count computation.
340 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
342 ## [2.6.3] - 2023-06-19
346 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
347 - Update strategies internals after statistics computation.
351 - Optimize O(1) queue implementation.
353 ## [2.6.2] - 2023-06-12
357 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
359 ## [2.6.1] - 2023-06-10
363 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
367 - Fix average statistics computation: ensure failed tasks are not accounted.
369 ## [2.6.0] - 2023-06-09
373 - Add `LEAST_ELU` worker choice strategy (experimental).
374 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
378 - Refactor pool worker node usage internals.
379 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
380 - Breaking change: pool information `info` property object fields have been renamed.
384 - Fix wait time accounting.
385 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
386 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
388 ## [2.5.4] - 2023-06-07
392 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
396 - Compute statistics at the worker level only if needed.
397 - Add `worker_threads` options to thread pool options.
401 - Make the `LEAST_BUSY` strategy only relies on task runtime.
403 ## [2.5.3] - 2023-06-04
407 - Refine pool information content.
408 - Limit pool internals public exposure.
410 ## [2.5.2] - 2023-06-02
414 - Add `taskError` pool event for task execution error.
415 - Add pool information `info` property to pool.
416 - Emit pool information on `busy` and `full` pool events.
418 ## [2.5.1] - 2023-06-01
422 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
423 - Add `error` pool event for uncaught worker error.
425 ## [2.5.0] - 2023-05-31
429 - Switch pool event emitter to `EventEmitterAsyncResource`.
430 - Add tasks wait time accounting in per worker tasks usage.
431 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
435 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
437 ## [2.4.14] - 2023-05-09
441 - Ensure no undefined task runtime can land in the tasks history.
442 - Fix median computation implementation once again.
446 - Unit tests for median and queue implementations.
448 ## [2.4.13] - 2023-05-08
452 - Fix worker choice strategy options validation.
453 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
455 ## [2.4.12] - 2023-05-06
459 - Support multiple task functions per worker.
460 - Add custom worker weights support to worker choice strategies options.
464 - Use O(1) queue implementation for tasks queueing.
468 - Fix median computation implementation.
469 - Fix fair share worker choice strategy internals update.
471 ## [2.4.11] - 2023-04-23
475 - Optimize free worker finding in worker choice strategies.
477 ## [2.4.10] - 2023-04-15
481 - Fix typescript type definition for task function: ensure the input data is optional.
482 - Fix typescript type definition for pool execute(): ensure the input data is optional.
484 ## [2.4.9] - 2023-04-15
488 - Add tasks queue enablement runtime setter to pool.
489 - Add tasks queue options runtime setter to pool.
490 - Add worker choice strategy options runtime setter to pool.
494 - Remove the tasks queuing experimental status.
498 - Fix task function type definition and validation.
499 - Fix worker choice strategy options handling.
501 ## [2.4.8] - 2023-04-12
505 - Fix message between main worker and worker type definition for tasks.
506 - Fix code documentation.
508 ## [2.4.7] - 2023-04-11
512 - Add worker tasks queue options to pool options.
516 - Fix missing documentation.
518 ## [2.4.6] - 2023-04-10
522 - Ensure one task at a time is executed per worker with tasks queueing enabled.
523 - Properly count worker executing tasks with tasks queueing enabled.
525 ## [2.4.5] - 2023-04-09
529 - Use monotonic high resolution timer for worker tasks runtime.
530 - Add worker tasks median runtime to statistics.
531 - Add worker tasks queue (experimental).
533 ## [2.4.4] - 2023-04-07
537 - Add `PoolEvents` enumeration and `PoolEvent` type.
541 - Destroy worker only on alive check.
543 ## [2.4.3] - 2023-04-07
547 - Fix typedoc generation with inheritance.
549 ## [2.4.2] - 2023-04-06
553 - Add `full` event to dynamic pool.
554 - Keep worker choice strategy in memory for conditional reuse.
558 - Fix possible negative worker key at worker removal in worker choice strategies.
560 ## [2.4.1] - 2023-04-05
564 - Optimize worker choice strategy for dynamic pool.
568 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
570 ## [2.4.0] - 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.
583 - Optimize tasks usage statistics requirements for worker choice strategy.
587 - Ensure trimmable characters are checked at pool initialization.
588 - Fix message id integer overflow.
589 - Fix pool worker removal in worker choice strategy internals.
590 - Fix package publication with pnpm.
592 ## [2.4.0-3] - 2023-04-04
596 - Add `LESS_BUSY` worker choice strategy.
600 - Optimize worker storage in pool.
601 - Optimize worker alive status check.
602 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
603 - Optimize `LESS_USED` worker choice strategy.
604 - Update benchmarks versus external threads pools.
608 - Ensure trimmable characters are checked at pool initialization.
609 - Fix message id integer overflow.
610 - Fix pool worker removal in worker choice strategy internals.
611 - Fix package publication with pnpm.
613 ## [2.4.0-2] - 2023-04-03
617 - Add `LESS_BUSY` worker choice strategy.
621 - Optimize worker storage in pool.
622 - Optimize worker alive status check.
623 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
624 - Optimize `LESS_USED` worker choice strategy.
628 - Ensure trimmable characters are checked at pool initialization.
629 - Fix message id integer overflow.
630 - Fix pool worker removal in worker choice strategy internals.
631 - Fix package publication with pnpm.
633 ## [2.4.0-1] - 2023-04-03
637 - Add `LESS_BUSY` worker choice strategy.
641 - Optimize worker storage in pool.
642 - Optimize worker alive status check.
643 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
644 - Optimize `LESS_USED` worker choice strategy.
648 - Ensure trimmable characters are checked at pool initialization.
649 - Fix message id integer overflow.
650 - Fix pool worker removal in worker choice strategy internals.
652 ## [2.4.0-0] - 2023-04-03
656 - Add `LESS_BUSY` worker choice strategy.
660 - Optimize worker storage in pool.
661 - Optimize worker alive status check.
662 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
663 - Optimize `LESS_USED` worker choice strategy.
667 - Ensure trimmable characters are checked at pool initialization.
668 - Fix message id integer overflow.
669 - Fix pool worker removal in worker choice strategy internals.
671 ## [2.3.10] - 2023-03-18
675 - Fix package.json `exports` syntax for ESM and CommonJS.
679 - Permit SemVer pre-release publication.
681 ## [2.3.10-2] - 2023-03-18
685 - Fix package.json `exports` syntax for ESM and CommonJS.
687 ## [2.3.10-1] - 2023-03-18
691 - Permit SemVer pre-release publication.
693 ## [2.3.10-0] - 2023-03-18
697 - Fix package.json `exports` syntax for ESM and CommonJS.
699 ## [2.3.9] - 2023-03-18
703 - Introduce ESM module support along with CommonJS one.
707 - Fix brown paper bag bug referencing the same object literal.
709 ## [2.3.8] - 2023-03-18
713 - Switch internal benchmarking code to benny.
714 - Switch to TypeScript 5.x.x.
715 - Switch rollup bundler plugins to core ones.
716 - Switch to TSDoc syntax.
717 - Enforce conventional commits.
721 - Fix random integer generator.
722 - Fix worker choice strategy pool type identification at initialization.
724 ## [2.3.7] - 2022-10-23
728 - Switch to open collective FOSS project funding platform.
729 - Switch to ts-standard linter configuration on TypeScript code.
733 - Fixed missing async on pool execute method.
734 - Fixed typing in TypeScript example.
735 - Fixed types in unit tests.
737 ## [2.3.6] - 2022-10-22
741 - Cleanup pool attributes and methods.
742 - Refine error types thrown.
746 - Fix continuous integration build on windows.
747 - Fix code coverage reporting by using c8 instead of nyc.
749 ## [2.3.5] - 2022-10-21
753 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
754 - Optimize tasks usage lookup implementation.
758 - Fix missed pool event emitter type export.
759 - Fix typedoc documentation generation.
761 ## [2.3.4] - 2022-10-17
765 - Fully automate release process with release-it.
769 - Optimize fair share task scheduling algorithm implementation.
770 - Update benchmarks versus external pools results with latest version.
772 ## [2.3.3] - 2022-10-15
776 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
778 ## [2.3.2] - 2022-10-14
782 - Optimize fair share worker selection strategy implementation.
786 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
788 ## [2.3.1] - 2022-10-13
792 - Pool worker choice strategies:
793 - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
794 - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
796 ## [2.2.2] - 2022-10-09
800 - Fixed `README.md` file.
802 ## [2.2.1] - 2022-10-08
806 - Dynamic worker choice strategy change at runtime.
808 ## [2.2.0] - 2022-01-05
812 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
814 ## [2.1.0] - 2021-08-29
818 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
822 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
823 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
824 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
825 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
827 ## [2.0.2] - 2021-05-12
831 - Fix `busy` event emission on fixed pool type
833 ## [2.0.1] - 2021-03-16
837 - Check if pool options are properly set.
838 - `busy` event is emitted on all pool types.
840 ## [2.0.0] - 2021-03-01
844 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
848 - `FullPool` event is now renamed to `busy`.
849 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
850 _Find more details on our JSDoc._
852 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
854 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
856 ### Pool options types declaration merge
858 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
860 #### New `export` strategy
864 const DynamicThreadPool = require('poolifier/lib/dynamic')
866 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
869 But you should always prefer just using
872 const { DynamicThreadPool } = require('poolifier')
875 #### New type definitions for input data and response
877 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
878 _This is not a limitation by poolifier but Node.js._
880 #### Public property replacements
882 `numWorkers` property is now `numberOfWorkers`
884 #### Internal (protected) properties and methods renaming
886 These properties are not intended for end users
888 - `id` => `nextMessageId`
890 These methods are not intended for end users
892 - `_chooseWorker` => `chooseWorker`
893 - `_newWorker` => `createWorker`
894 - `_execute` => `internalExecute`
895 - `_chooseWorker` => `chooseWorker`
896 - `_checkAlive` => `checkAlive`
898 - `_runAsync` => `runAsync`
900 ## [1.1.0] - 2020-05-21
904 - ThreadWorker support async functions as option
905 - Various external library patches
907 ## [1.0.0] - 2020-01-24
911 - FixedThreadPool implementation
912 - DynamicThreadPool implementation
913 - WorkerThread implementation to improve developer experience