CHANGELOG.md

   1 # Changelog
   2
   3 All notable changes to this project will be documented in this file.
   4
   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).
   7
   8 ## [Unreleased]
   9
  10 ## [2.6.38] - 2023-08-30
  11
  12 ### Added
  13
  14 - Bundle typescript types declaration into one file.
  15
  16 ### Changed
  17
  18 - Improve interleaved weighted round robin worker choice strategy implementation.
  19
  20 ## [2.6.37] - 2023-08-28
  21
  22 ### Fixed
  23
  24 - Ensure unused worker usage statistics are deleted at runtime.
  25
  26 ### Changed
  27
  28 - Rename worker choice strategy options `choiceRetries` to `retries`.
  29 - Avoid unnecessary branching in worker choice strategies.
  30
  31 ## [2.6.36] - 2023-08-27
  32
  33 ### Fixed
  34
  35 - Fix pool `execute()` arguments check.
  36
  37 ### Changed
  38
  39 - Make continuous tasks stealing algorithm less aggressive.
  40 - Fine tune tasks stealing algorithm under back pressure.
  41
  42 ## [2.6.35] - 2023-08-25
  43
  44 ### Fixed
  45
  46 - Don't account worker usage statistics for tasks that have failed.
  47 - Fix pool information runtime and wait time median computation.
  48
  49 ### Changed
  50
  51 - Update simple moving average implementation to use a circular buffer.
  52 - Update simple moving median implementation to use a circular buffer.
  53 - Account for stolen tasks in worker usage statistics and pool information.
  54
  55 ### Added
  56
  57 - Continuous tasks stealing algorithm.
  58
  59 ## [2.6.34] - 2023-08-24
  60
  61 ### Fixes
  62
  63 - Avoid cascading tasks stealing under back pressure.
  64
  65 ### Changed
  66
  67 - Add fastpath to queued tasks rescheduling.
  68
  69 ## [2.6.33] - 2023-08-24
  70
  71 ### Fixed
  72
  73 - Fix queued tasks rescheduling.
  74
  75 ### Changed
  76
  77 - Rename tasks queue options `queueMaxSize` to `size`.
  78
  79 ### Added
  80
  81 - Task stealing scheduling algorithm if tasks queueing is enabled.
  82
  83 ## [2.6.32] - 2023-08-23
  84
  85 ### Fixed
  86
  87 - Ensure no task can be executed when the pool is destroyed.
  88
  89 ### Added
  90
  91 - Add `queueMaxSize` option to tasks queue options.
  92 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
  93 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
  94
  95 ## [2.6.31] - 2023-08-20
  96
  97 ### Fixed
  98
  99 - Fix worker choice strategy retries mechanism in some edge cases.
 100
 101 ### Changed
 102
 103 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
 104 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
 105
 106 ## [2.6.30] - 2023-08-19
 107
 108 ### Fixed
 109
 110 - Ensure pool event `backPressure` is emitted.
 111 - Ensure pool event `full` is emitted only once.
 112 - Ensure worker node cannot be instantiated without proper arguments.
 113
 114 ## [2.6.29] - 2023-08-18
 115
 116 ### Fixed
 117
 118 - Fix race condition between ready and task functions worker message handling at startup.
 119 - Fix duplicate task function worker usage statistics computation per task function.
 120 - Update task function worker usage statistics if and only if there's at least two different task functions.
 121 - Fix race condition at task function worker usage executing task computation leading to negative value.
 122
 123 ### Added
 124
 125 - 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).
 126 - Use back pressure detection in worker choice strategies.
 127 - Add worker choice strategies retries mechanism if no worker is eligible.
 128
 129 ## [2.6.28] - 2023-08-16
 130
 131 ### Fixed
 132
 133 - Ensure pool workers are properly initialized.
 134
 135 ### Added
 136
 137 - HTTP server pool examples: express-cluster, express-hybrid.
 138
 139 ### Changed
 140
 141 - Remove now useless branching in worker hot code path.
 142
 143 ## [2.6.27] - 2023-08-15
 144
 145 ### Fixed
 146
 147 - Add `KillHandler` type definition to exported types.
 148
 149 ### Added
 150
 151 - Add `destroy` event to pool API.
 152
 153 ## [2.6.26] - 2023-08-15
 154
 155 ### Added
 156
 157 - Add kill handler to worker options allowing to execute custom code when worker is killed.
 158 - Add `listTaskFunctions()` method to pool API.
 159 - SMTP server pool example: nodemailer.
 160
 161 ## [2.6.25] - 2023-08-13
 162
 163 ### Added
 164
 165 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
 166 - WebSocket server pool examples: ws-cluster, ws-hybrid.
 167
 168 ## [2.6.24] - 2023-08-12
 169
 170 ### Added
 171
 172 - Add array of transferable objects to the `execute()` method arguments.
 173 - WebSocket server pool examples: ws-worker_threads.
 174
 175 ## [2.6.23] - 2023-08-11
 176
 177 ### Fixed
 178
 179 - 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.
 180
 181 ### Added
 182
 183 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
 184 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
 185
 186 ## [2.6.22] - 2023-08-10
 187
 188 ### Fixed
 189
 190 - Add missing `types` field to package.json `exports`.
 191
 192 ### Changed
 193
 194 - Structure markdown documentation (PR #811).
 195
 196 ## [2.6.21] - 2023-08-03
 197
 198 ### Changed
 199
 200 - Improve code documentation.
 201 - Code refactoring and cleanup for better maintainability and readability.
 202
 203 ## [2.6.20] - 2023-07-21
 204
 205 ### Fixed
 206
 207 - Fix queued tasks redistribution on error task execution starvation.
 208 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
 209
 210 ### Changed
 211
 212 - Drastically reduce lookups by worker in the worker nodes.
 213
 214 ## [2.6.19] - 2023-07-20
 215
 216 ### Added
 217
 218 - Dedicated internal communication channel for worker_threads pools.
 219
 220 ## [2.6.18] - 2023-07-19
 221
 222 ### Changed
 223
 224 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
 225
 226 ## [2.6.17] - 2023-07-16
 227
 228 ### Added
 229
 230 - Add `listTaskFunctions()` method to worker API.
 231
 232 ## [2.6.16] - 2023-07-12
 233
 234 ### Fixed
 235
 236 - Fix pool startup detection.
 237 - Fix worker task functions handling.
 238
 239 ## [2.6.15] - 2023-07-11
 240
 241 ### Added
 242
 243 - Take into account worker node readiness in worker choice strategies.
 244
 245 ## [2.6.14] - 2023-07-10
 246
 247 ### Fixed
 248
 249 - Fix task function statistics tracking.
 250
 251 ## [2.6.13] - 2023-07-10
 252
 253 ### Added
 254
 255 - Add per task function statistics tracking.
 256 - Add public methods to manipulate the worker task functions at runtime.
 257
 258 ## [2.6.12] - 2023-07-09
 259
 260 ### Fixed
 261
 262 - Workaround import issue with `node:os` module in node 16.x.x.
 263
 264 ## [2.6.11] - 2023-07-09
 265
 266 ### Fixed
 267
 268 - Fix pool readiness semantic.
 269
 270 ## [2.6.10] - 2023-07-08
 271
 272 ### Fixed
 273
 274 - Ensure workers are not recreated on error at pool startup.
 275
 276 ### Added
 277
 278 - Add `ready` and `strategy` fields to pool information.
 279 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
 280 - Add dynamic pool sizing checks.
 281
 282 ## [2.6.9] - 2023-07-07
 283
 284 ### Fixed
 285
 286 - Recreate the right worker type on uncaught exception.
 287
 288 ### Added
 289
 290 - Add minimum and maximum to internal measurement statistics.
 291 - Add `runTime` and `waitTime` to pool information.
 292 - Check worker inactive time only on dynamic worker.
 293
 294 ## [2.6.8] - 2023-07-03
 295
 296 ### Fixed
 297
 298 - Brown paper bag release to fix version handling in pool information.
 299
 300 ## [2.6.7] - 2023-07-03
 301
 302 ### Fixed
 303
 304 - Ensure worker queued tasks at error are reassigned to other pool workers.
 305
 306 ### Added
 307
 308 - Add pool `utilization` ratio to pool information.
 309 - Add `version` to pool information.
 310 - Add worker information to worker nodes.
 311
 312 ## [2.6.6] - 2023-07-01
 313
 314 ### Added
 315
 316 - Add safe helper `availableParallelism()` to help sizing the pool.
 317
 318 ### Fixed
 319
 320 - Ensure message handler is only registered in worker.
 321
 322 ## [2.6.5] - 2023-06-27
 323
 324 ### Known issues
 325
 326 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
 327
 328 ### Fixed
 329
 330 - Artificial version bump to 2.6.5 to workaround publication issue.
 331 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
 332 - Ensure pool event is emitted before task error promise rejection.
 333 - Fix queued tasks count computation.
 334
 335 ### Removed
 336
 337 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
 338
 339 ## [2.6.4] - 2023-06-27
 340
 341 ### Known issues
 342
 343 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
 344
 345 ### Fixed
 346
 347 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
 348 - Ensure pool event is emitted before task error promise rejection.
 349 - Fix queued tasks count computation.
 350
 351 ### Removed
 352
 353 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
 354
 355 ## [2.6.3] - 2023-06-19
 356
 357 ### Fixed
 358
 359 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
 360 - Update strategies internals after statistics computation.
 361
 362 ### Changed
 363
 364 - Optimize O(1) queue implementation.
 365
 366 ## [2.6.2] - 2023-06-12
 367
 368 ### Fixed
 369
 370 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
 371
 372 ## [2.6.1] - 2023-06-10
 373
 374 ### Added
 375
 376 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
 377
 378 ### Fixed
 379
 380 - Fix average statistics computation: ensure failed tasks are not accounted.
 381
 382 ## [2.6.0] - 2023-06-09
 383
 384 ### Added
 385
 386 - Add `LEAST_ELU` worker choice strategy (experimental).
 387 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
 388
 389 ### Changed
 390
 391 - Refactor pool worker node usage internals.
 392 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
 393 - Breaking change: pool information `info` property object fields have been renamed.
 394
 395 ### Fixed
 396
 397 - Fix wait time accounting.
 398 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
 399 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
 400
 401 ## [2.5.4] - 2023-06-07
 402
 403 ### Added
 404
 405 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
 406
 407 ### Changed
 408
 409 - Compute statistics at the worker level only if needed.
 410 - Add `worker_threads` options to thread pool options.
 411
 412 ### Fixed
 413
 414 - Make the `LEAST_BUSY` strategy only relies on task runtime.
 415
 416 ## [2.5.3] - 2023-06-04
 417
 418 ### Changed
 419
 420 - Refine pool information content.
 421 - Limit pool internals public exposure.
 422
 423 ## [2.5.2] - 2023-06-02
 424
 425 ### Added
 426
 427 - Add `taskError` pool event for task execution error.
 428 - Add pool information `info` property to pool.
 429 - Emit pool information on `busy` and `full` pool events.
 430
 431 ## [2.5.1] - 2023-06-01
 432
 433 ### Added
 434
 435 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
 436 - Add `error` pool event for uncaught worker error.
 437
 438 ## [2.5.0] - 2023-05-31
 439
 440 ### Added
 441
 442 - Switch pool event emitter to `EventEmitterAsyncResource`.
 443 - Add tasks wait time accounting in per worker tasks usage.
 444 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
 445
 446 ### Changed
 447
 448 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
 449
 450 ## [2.4.14] - 2023-05-09
 451
 452 ### Fixed
 453
 454 - Ensure no undefined task runtime can land in the tasks history.
 455 - Fix median computation implementation once again.
 456
 457 ### Added
 458
 459 - Unit tests for median and queue implementations.
 460
 461 ## [2.4.13] - 2023-05-08
 462
 463 ### Fixed
 464
 465 - Fix worker choice strategy options validation.
 466 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
 467
 468 ## [2.4.12] - 2023-05-06
 469
 470 ### Added
 471
 472 - Support multiple task functions per worker.
 473 - Add custom worker weights support to worker choice strategies options.
 474
 475 ### Changed
 476
 477 - Use O(1) queue implementation for tasks queueing.
 478
 479 ### Fixed
 480
 481 - Fix median computation implementation.
 482 - Fix fair share worker choice strategy internals update.
 483
 484 ## [2.4.11] - 2023-04-23
 485
 486 ### Changed
 487
 488 - Optimize free worker finding in worker choice strategies.
 489
 490 ## [2.4.10] - 2023-04-15
 491
 492 ### Fixed
 493
 494 - Fix typescript type definition for task function: ensure the input data is optional.
 495 - Fix typescript type definition for pool execute(): ensure the input data is optional.
 496
 497 ## [2.4.9] - 2023-04-15
 498
 499 ### Added
 500
 501 - Add tasks queue enablement runtime setter to pool.
 502 - Add tasks queue options runtime setter to pool.
 503 - Add worker choice strategy options runtime setter to pool.
 504
 505 ### Changed
 506
 507 - Remove the tasks queuing experimental status.
 508
 509 ### Fixed
 510
 511 - Fix task function type definition and validation.
 512 - Fix worker choice strategy options handling.
 513
 514 ## [2.4.8] - 2023-04-12
 515
 516 ### Fixed
 517
 518 - Fix message between main worker and worker type definition for tasks.
 519 - Fix code documentation.
 520
 521 ## [2.4.7] - 2023-04-11
 522
 523 ### Added
 524
 525 - Add worker tasks queue options to pool options.
 526
 527 ### Fixed
 528
 529 - Fix missing documentation.
 530
 531 ## [2.4.6] - 2023-04-10
 532
 533 ### Fixed
 534
 535 - Ensure one task at a time is executed per worker with tasks queueing enabled.
 536 - Properly count worker executing tasks with tasks queueing enabled.
 537
 538 ## [2.4.5] - 2023-04-09
 539
 540 ### Added
 541
 542 - Use monotonic high resolution timer for worker tasks runtime.
 543 - Add worker tasks median runtime to statistics.
 544 - Add worker tasks queue (experimental).
 545
 546 ## [2.4.4] - 2023-04-07
 547
 548 ### Added
 549
 550 - Add `PoolEvents` enumeration and `PoolEvent` type.
 551
 552 ### Fixed
 553
 554 - Destroy worker only on alive check.
 555
 556 ## [2.4.3] - 2023-04-07
 557
 558 ### Fixed
 559
 560 - Fix typedoc generation with inheritance.
 561
 562 ## [2.4.2] - 2023-04-06
 563
 564 ### Added
 565
 566 - Add `full` event to dynamic pool.
 567 - Keep worker choice strategy in memory for conditional reuse.
 568
 569 ### Fixed
 570
 571 - Fix possible negative worker key at worker removal in worker choice strategies.
 572
 573 ## [2.4.1] - 2023-04-05
 574
 575 ### Changed
 576
 577 - Optimize worker choice strategy for dynamic pool.
 578
 579 ### Fixed
 580
 581 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
 582
 583 ## [2.4.0] - 2023-04-04
 584
 585 ### Added
 586
 587 - Add `LESS_BUSY` worker choice strategy.
 588
 589 ### Changed
 590
 591 - Optimize worker storage in pool.
 592 - Optimize worker alive status check.
 593 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 594 - Optimize `LESS_USED` worker choice strategy.
 595 - Update benchmarks versus external threads pools.
 596 - Optimize tasks usage statistics requirements for worker choice strategy.
 597
 598 ### Fixed
 599
 600 - Ensure trimmable characters are checked at pool initialization.
 601 - Fix message id integer overflow.
 602 - Fix pool worker removal in worker choice strategy internals.
 603 - Fix package publication with pnpm.
 604
 605 ## [2.4.0-3] - 2023-04-04
 606
 607 ### Added
 608
 609 - Add `LESS_BUSY` worker choice strategy.
 610
 611 ### Changed
 612
 613 - Optimize worker storage in pool.
 614 - Optimize worker alive status check.
 615 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 616 - Optimize `LESS_USED` worker choice strategy.
 617 - Update benchmarks versus external threads pools.
 618
 619 ### Fixed
 620
 621 - Ensure trimmable characters are checked at pool initialization.
 622 - Fix message id integer overflow.
 623 - Fix pool worker removal in worker choice strategy internals.
 624 - Fix package publication with pnpm.
 625
 626 ## [2.4.0-2] - 2023-04-03
 627
 628 ### Added
 629
 630 - Add `LESS_BUSY` worker choice strategy.
 631
 632 ### Changed
 633
 634 - Optimize worker storage in pool.
 635 - Optimize worker alive status check.
 636 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 637 - Optimize `LESS_USED` worker choice strategy.
 638
 639 ### Fixed
 640
 641 - Ensure trimmable characters are checked at pool initialization.
 642 - Fix message id integer overflow.
 643 - Fix pool worker removal in worker choice strategy internals.
 644 - Fix package publication with pnpm.
 645
 646 ## [2.4.0-1] - 2023-04-03
 647
 648 ### Added
 649
 650 - Add `LESS_BUSY` worker choice strategy.
 651
 652 ### Changed
 653
 654 - Optimize worker storage in pool.
 655 - Optimize worker alive status check.
 656 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 657 - Optimize `LESS_USED` worker choice strategy.
 658
 659 ### Fixed
 660
 661 - Ensure trimmable characters are checked at pool initialization.
 662 - Fix message id integer overflow.
 663 - Fix pool worker removal in worker choice strategy internals.
 664
 665 ## [2.4.0-0] - 2023-04-03
 666
 667 ### Added
 668
 669 - Add `LESS_BUSY` worker choice strategy.
 670
 671 ### Changed
 672
 673 - Optimize worker storage in pool.
 674 - Optimize worker alive status check.
 675 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 676 - Optimize `LESS_USED` worker choice strategy.
 677
 678 ### Fixed
 679
 680 - Ensure trimmable characters are checked at pool initialization.
 681 - Fix message id integer overflow.
 682 - Fix pool worker removal in worker choice strategy internals.
 683
 684 ## [2.3.10] - 2023-03-18
 685
 686 ### Fixed
 687
 688 - Fix package.json `exports` syntax for ESM and CommonJS.
 689
 690 ### Changed
 691
 692 - Permit SemVer pre-release publication.
 693
 694 ## [2.3.10-2] - 2023-03-18
 695
 696 ### Fixed
 697
 698 - Fix package.json `exports` syntax for ESM and CommonJS.
 699
 700 ## [2.3.10-1] - 2023-03-18
 701
 702 ### Changed
 703
 704 - Permit SemVer pre-release publication.
 705
 706 ## [2.3.10-0] - 2023-03-18
 707
 708 ### Fixed
 709
 710 - Fix package.json `exports` syntax for ESM and CommonJS.
 711
 712 ## [2.3.9] - 2023-03-18
 713
 714 ### Changed
 715
 716 - Introduce ESM module support along with CommonJS one.
 717
 718 ### Fixed
 719
 720 - Fix brown paper bag bug referencing the same object literal.
 721
 722 ## [2.3.8] - 2023-03-18
 723
 724 ### Changed
 725
 726 - Switch internal benchmarking code to benny.
 727 - Switch to TypeScript 5.x.x.
 728 - Switch rollup bundler plugins to core ones.
 729 - Switch to TSDoc syntax.
 730 - Enforce conventional commits.
 731
 732 ### Fixed
 733
 734 - Fix random integer generator.
 735 - Fix worker choice strategy pool type identification at initialization.
 736
 737 ## [2.3.7] - 2022-10-23
 738
 739 ### Changed
 740
 741 - Switch to open collective FOSS project funding platform.
 742 - Switch to ts-standard linter configuration on TypeScript code.
 743
 744 ### Fixed
 745
 746 - Fixed missing async on pool execute method.
 747 - Fixed typing in TypeScript example.
 748 - Fixed types in unit tests.
 749
 750 ## [2.3.6] - 2022-10-22
 751
 752 ### Changed
 753
 754 - Cleanup pool attributes and methods.
 755 - Refine error types thrown.
 756
 757 ### Fixed
 758
 759 - Fix continuous integration build on windows.
 760 - Fix code coverage reporting by using c8 instead of nyc.
 761
 762 ## [2.3.5] - 2022-10-21
 763
 764 ### Changed
 765
 766 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
 767 - Optimize tasks usage lookup implementation.
 768
 769 ### Fixed
 770
 771 - Fix missed pool event emitter type export.
 772 - Fix typedoc documentation generation.
 773
 774 ## [2.3.4] - 2022-10-17
 775
 776 ### Added
 777
 778 - Fully automate release process with release-it.
 779
 780 ### Changed
 781
 782 - Optimize fair share task scheduling algorithm implementation.
 783 - Update benchmarks versus external pools results with latest version.
 784
 785 ## [2.3.3] - 2022-10-15
 786
 787 ### Added
 788
 789 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
 790
 791 ## [2.3.2] - 2022-10-14
 792
 793 ### Changed
 794
 795 - Optimize fair share worker selection strategy implementation.
 796
 797 ### Fixed
 798
 799 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
 800
 801 ## [2.3.1] - 2022-10-13
 802
 803 ### Added
 804
 805 - Pool worker choice strategies:
 806   - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
 807   - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
 808
 809 ## [2.2.2] - 2022-10-09
 810
 811 ### Fixed
 812
 813 - Fixed `README.md` file.
 814
 815 ## [2.2.1] - 2022-10-08
 816
 817 ### Added
 818
 819 - Dynamic worker choice strategy change at runtime.
 820
 821 ## [2.2.0] - 2022-01-05
 822
 823 ### Breaking Changes
 824
 825 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
 826
 827 ## [2.1.0] - 2021-08-29
 828
 829 ### Added
 830
 831 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
 832
 833 ### Breaking Changes
 834
 835 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
 836 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
 837 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
 838 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
 839
 840 ## [2.0.2] - 2021-05-12
 841
 842 ### Bug fixes
 843
 844 - Fix `busy` event emission on fixed pool type
 845
 846 ## [2.0.1] - 2021-03-16
 847
 848 ### Bug fixes
 849
 850 - Check if pool options are properly set.
 851 - `busy` event is emitted on all pool types.
 852
 853 ## [2.0.0] - 2021-03-01
 854
 855 ### Bug fixes
 856
 857 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
 858
 859 ### Breaking Changes
 860
 861 - `FullPool` event is now renamed to `busy`.
 862 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
 863   _Find more details on our JSDoc._
 864
 865 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
 866
 867 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
 868
 869 ### Pool options types declaration merge
 870
 871 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
 872
 873 #### New `export` strategy
 874
 875 ```js
 876 // Before
 877 const DynamicThreadPool = require('poolifier/lib/dynamic')
 878 // After
 879 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
 880 ```
 881
 882 But you should always prefer just using
 883
 884 ```js
 885 const { DynamicThreadPool } = require('poolifier')
 886 ```
 887
 888 #### New type definitions for input data and response
 889
 890 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
 891 _This is not a limitation by poolifier but Node.js._
 892
 893 #### Public property replacements
 894
 895 `numWorkers` property is now `numberOfWorkers`
 896
 897 #### Internal (protected) properties and methods renaming
 898
 899 These properties are not intended for end users
 900
 901 - `id` => `nextMessageId`
 902
 903 These methods are not intended for end users
 904
 905 - `_chooseWorker` => `chooseWorker`
 906 - `_newWorker` => `createWorker`
 907 - `_execute` => `internalExecute`
 908 - `_chooseWorker` => `chooseWorker`
 909 - `_checkAlive` => `checkAlive`
 910 - `_run` => `run`
 911 - `_runAsync` => `runAsync`
 912
 913 ## [1.1.0] - 2020-05-21
 914
 915 ### Added
 916
 917 - ThreadWorker support async functions as option
 918 - Various external library patches
 919
 920 ## [1.0.0] - 2020-01-24
 921
 922 ### Added
 923
 924 - FixedThreadPool implementation
 925 - DynamicThreadPool implementation
 926 - WorkerThread implementation to improve developer experience