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 ### Fixed
  11
  12 - Do not pre-choose in WRR worker choice strategy to avoid bias.
  13
  14 ## [2.6.39] - 2023-08-30
  15
  16 ### Fixed
  17
  18 - Fix race condition in worker choice strategies at worker node info querying while not yet initialized .
  19
  20 ## [2.6.38] - 2023-08-30
  21
  22 ### Added
  23
  24 - Bundle typescript types declaration into one file.
  25
  26 ### Changed
  27
  28 - Improve interleaved weighted round robin worker choice strategy implementation.
  29
  30 ## [2.6.37] - 2023-08-28
  31
  32 ### Fixed
  33
  34 - Ensure unused worker usage statistics are deleted at runtime.
  35
  36 ### Changed
  37
  38 - Rename worker choice strategy options `choiceRetries` to `retries`.
  39 - Avoid unnecessary branching in worker choice strategies.
  40
  41 ## [2.6.36] - 2023-08-27
  42
  43 ### Fixed
  44
  45 - Fix pool `execute()` arguments check.
  46
  47 ### Changed
  48
  49 - Make continuous tasks stealing algorithm less aggressive.
  50 - Fine tune tasks stealing algorithm under back pressure.
  51
  52 ## [2.6.35] - 2023-08-25
  53
  54 ### Fixed
  55
  56 - Don't account worker usage statistics for tasks that have failed.
  57 - Fix pool information runtime and wait time median computation.
  58
  59 ### Changed
  60
  61 - Update simple moving average implementation to use a circular buffer.
  62 - Update simple moving median implementation to use a circular buffer.
  63 - Account for stolen tasks in worker usage statistics and pool information.
  64
  65 ### Added
  66
  67 - Continuous tasks stealing algorithm.
  68
  69 ## [2.6.34] - 2023-08-24
  70
  71 ### Fixes
  72
  73 - Avoid cascading tasks stealing under back pressure.
  74
  75 ### Changed
  76
  77 - Add fastpath to queued tasks rescheduling.
  78
  79 ## [2.6.33] - 2023-08-24
  80
  81 ### Fixed
  82
  83 - Fix queued tasks rescheduling.
  84
  85 ### Changed
  86
  87 - Rename tasks queue options `queueMaxSize` to `size`.
  88
  89 ### Added
  90
  91 - Task stealing scheduling algorithm if tasks queueing is enabled.
  92
  93 ## [2.6.32] - 2023-08-23
  94
  95 ### Fixed
  96
  97 - Ensure no task can be executed when the pool is destroyed.
  98
  99 ### Added
 100
 101 - Add `queueMaxSize` option to tasks queue options.
 102 - Add O(1) deque implementation implemented with doubly linked list and use it for tasks queueing.
 103 - Add tasks stealing algorithm when a worker node queue is back pressured if tasks queueing is enabled.
 104
 105 ## [2.6.31] - 2023-08-20
 106
 107 ### Fixed
 108
 109 - Fix worker choice strategy retries mechanism in some edge cases.
 110
 111 ### Changed
 112
 113 - Make orthogonal worker choice strategies tasks distribution and created dynamic worker usage.
 114 - Remove the experimental status of the `LEAST_ELU` worker choice strategy.
 115
 116 ## [2.6.30] - 2023-08-19
 117
 118 ### Fixed
 119
 120 - Ensure pool event `backPressure` is emitted.
 121 - Ensure pool event `full` is emitted only once.
 122 - Ensure worker node cannot be instantiated without proper arguments.
 123
 124 ## [2.6.29] - 2023-08-18
 125
 126 ### Fixed
 127
 128 - Fix race condition between ready and task functions worker message handling at startup.
 129 - Fix duplicate task function worker usage statistics computation per task function.
 130 - Update task function worker usage statistics if and only if there's at least two different task functions.
 131 - Fix race condition at task function worker usage executing task computation leading to negative value.
 132
 133 ### Added
 134
 135 - 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).
 136 - Use back pressure detection in worker choice strategies.
 137 - Add worker choice strategies retries mechanism if no worker is eligible.
 138
 139 ## [2.6.28] - 2023-08-16
 140
 141 ### Fixed
 142
 143 - Ensure pool workers are properly initialized.
 144
 145 ### Added
 146
 147 - HTTP server pool examples: express-cluster, express-hybrid.
 148
 149 ### Changed
 150
 151 - Remove now useless branching in worker hot code path.
 152
 153 ## [2.6.27] - 2023-08-15
 154
 155 ### Fixed
 156
 157 - Add `KillHandler` type definition to exported types.
 158
 159 ### Added
 160
 161 - Add `destroy` event to pool API.
 162
 163 ## [2.6.26] - 2023-08-15
 164
 165 ### Added
 166
 167 - Add kill handler to worker options allowing to execute custom code when worker is killed.
 168 - Add `listTaskFunctions()` method to pool API.
 169 - SMTP server pool example: nodemailer.
 170
 171 ## [2.6.25] - 2023-08-13
 172
 173 ### Added
 174
 175 - HTTP server pool examples: fastify-cluster, fastify-hybrid.
 176 - WebSocket server pool examples: ws-cluster, ws-hybrid.
 177
 178 ## [2.6.24] - 2023-08-12
 179
 180 ### Added
 181
 182 - Add array of transferable objects to the `execute()` method arguments.
 183 - WebSocket server pool examples: ws-worker_threads.
 184
 185 ## [2.6.23] - 2023-08-11
 186
 187 ### Fixed
 188
 189 - 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.
 190
 191 ### Added
 192
 193 - HTTP client pool examples: fetch, node-fetch and axios with multiple task functions.
 194 - HTTP server pool examples: express-worker_threads, fastify-worker_threads.
 195
 196 ## [2.6.22] - 2023-08-10
 197
 198 ### Fixed
 199
 200 - Add missing `types` field to package.json `exports`.
 201
 202 ### Changed
 203
 204 - Structure markdown documentation (PR #811).
 205
 206 ## [2.6.21] - 2023-08-03
 207
 208 ### Changed
 209
 210 - Improve code documentation.
 211 - Code refactoring and cleanup for better maintainability and readability.
 212
 213 ## [2.6.20] - 2023-07-21
 214
 215 ### Fixed
 216
 217 - Fix queued tasks redistribution on error task execution starvation.
 218 - Ensure tasks queueing per worker condition is untangled from the pool busyness semantic.
 219
 220 ### Changed
 221
 222 - Drastically reduce lookups by worker in the worker nodes.
 223
 224 ## [2.6.19] - 2023-07-20
 225
 226 ### Added
 227
 228 - Dedicated internal communication channel for worker_threads pools.
 229
 230 ## [2.6.18] - 2023-07-19
 231
 232 ### Changed
 233
 234 - Code refactoring and cleanup for better maintainability and readability. Bundle size is a bit smaller.
 235
 236 ## [2.6.17] - 2023-07-16
 237
 238 ### Added
 239
 240 - Add `listTaskFunctions()` method to worker API.
 241
 242 ## [2.6.16] - 2023-07-12
 243
 244 ### Fixed
 245
 246 - Fix pool startup detection.
 247 - Fix worker task functions handling.
 248
 249 ## [2.6.15] - 2023-07-11
 250
 251 ### Added
 252
 253 - Take into account worker node readiness in worker choice strategies.
 254
 255 ## [2.6.14] - 2023-07-10
 256
 257 ### Fixed
 258
 259 - Fix task function statistics tracking.
 260
 261 ## [2.6.13] - 2023-07-10
 262
 263 ### Added
 264
 265 - Add per task function statistics tracking.
 266 - Add public methods to manipulate the worker task functions at runtime.
 267
 268 ## [2.6.12] - 2023-07-09
 269
 270 ### Fixed
 271
 272 - Workaround import issue with `node:os` module in node 16.x.x.
 273
 274 ## [2.6.11] - 2023-07-09
 275
 276 ### Fixed
 277
 278 - Fix pool readiness semantic.
 279
 280 ## [2.6.10] - 2023-07-08
 281
 282 ### Fixed
 283
 284 - Ensure workers are not recreated on error at pool startup.
 285
 286 ### Added
 287
 288 - Add `ready` and `strategy` fields to pool information.
 289 - Add pool event `ready` to notify when the number of workers created in the pool has reached the maximum size expected and are ready.
 290 - Add dynamic pool sizing checks.
 291
 292 ## [2.6.9] - 2023-07-07
 293
 294 ### Fixed
 295
 296 - Recreate the right worker type on uncaught exception.
 297
 298 ### Added
 299
 300 - Add minimum and maximum to internal measurement statistics.
 301 - Add `runTime` and `waitTime` to pool information.
 302 - Check worker inactive time only on dynamic worker.
 303
 304 ## [2.6.8] - 2023-07-03
 305
 306 ### Fixed
 307
 308 - Brown paper bag release to fix version handling in pool information.
 309
 310 ## [2.6.7] - 2023-07-03
 311
 312 ### Fixed
 313
 314 - Ensure worker queued tasks at error are reassigned to other pool workers.
 315
 316 ### Added
 317
 318 - Add pool `utilization` ratio to pool information.
 319 - Add `version` to pool information.
 320 - Add worker information to worker nodes.
 321
 322 ## [2.6.6] - 2023-07-01
 323
 324 ### Added
 325
 326 - Add safe helper `availableParallelism()` to help sizing the pool.
 327
 328 ### Fixed
 329
 330 - Ensure message handler is only registered in worker.
 331
 332 ## [2.6.5] - 2023-06-27
 333
 334 ### Known issues
 335
 336 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
 337
 338 ### Fixed
 339
 340 - Artificial version bump to 2.6.5 to workaround publication issue.
 341 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
 342 - Ensure pool event is emitted before task error promise rejection.
 343 - Fix queued tasks count computation.
 344
 345 ### Removed
 346
 347 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
 348
 349 ## [2.6.4] - 2023-06-27
 350
 351 ### Known issues
 352
 353 - Cluster pools tasks execution are not working by using ESM files extension: https://github.com/poolifier/poolifier/issues/782
 354
 355 ### Fixed
 356
 357 - Ensure cluster pool `destroy()` gracefully shutdowns worker's server.
 358 - Ensure pool event is emitted before task error promise rejection.
 359 - Fix queued tasks count computation.
 360
 361 ### Removed
 362
 363 - Remove unneeded worker_threads worker `MessageChannel` internal usage for IPC.
 364
 365 ## [2.6.3] - 2023-06-19
 366
 367 ### Fixed
 368
 369 - Ensure no tasks are queued when trying to soft kill a dynamic worker.
 370 - Update strategies internals after statistics computation.
 371
 372 ### Changed
 373
 374 - Optimize O(1) queue implementation.
 375
 376 ## [2.6.2] - 2023-06-12
 377
 378 ### Fixed
 379
 380 - Fix new worker use after creation in dynamic pool given the current worker choice strategy.
 381
 382 ## [2.6.1] - 2023-06-10
 383
 384 ### Added
 385
 386 - Add worker choice strategy documentation: [README.md](./docs/worker-choice-strategies.md).
 387
 388 ### Fixed
 389
 390 - Fix average statistics computation: ensure failed tasks are not accounted.
 391
 392 ## [2.6.0] - 2023-06-09
 393
 394 ### Added
 395
 396 - Add `LEAST_ELU` worker choice strategy (experimental).
 397 - Add tasks ELU instead of runtime support to `FAIR_SHARE` worker choice strategy.
 398
 399 ### Changed
 400
 401 - Refactor pool worker node usage internals.
 402 - Breaking change: refactor worker choice strategy statistics requirements: the syntax of the worker choice strategy options has changed.
 403 - Breaking change: pool information `info` property object fields have been renamed.
 404
 405 ### Fixed
 406
 407 - Fix wait time accounting.
 408 - Ensure worker choice strategy `LEAST_BUSY` accounts also tasks wait time.
 409 - Ensure worker choice strategy `LEAST_USED` accounts also queued tasks.
 410
 411 ## [2.5.4] - 2023-06-07
 412
 413 ### Added
 414
 415 - Add Event Loop Utilization (ELU) statistics to worker tasks usage.
 416
 417 ### Changed
 418
 419 - Compute statistics at the worker level only if needed.
 420 - Add `worker_threads` options to thread pool options.
 421
 422 ### Fixed
 423
 424 - Make the `LEAST_BUSY` strategy only relies on task runtime.
 425
 426 ## [2.5.3] - 2023-06-04
 427
 428 ### Changed
 429
 430 - Refine pool information content.
 431 - Limit pool internals public exposure.
 432
 433 ## [2.5.2] - 2023-06-02
 434
 435 ### Added
 436
 437 - Add `taskError` pool event for task execution error.
 438 - Add pool information `info` property to pool.
 439 - Emit pool information on `busy` and `full` pool events.
 440
 441 ## [2.5.1] - 2023-06-01
 442
 443 ### Added
 444
 445 - Add pool option `restartWorkerOnError` to restart worker on uncaught error. Default to `true`.
 446 - Add `error` pool event for uncaught worker error.
 447
 448 ## [2.5.0] - 2023-05-31
 449
 450 ### Added
 451
 452 - Switch pool event emitter to `EventEmitterAsyncResource`.
 453 - Add tasks wait time accounting in per worker tasks usage.
 454 - Add interleaved weighted round robin `INTERLEAVED_WEIGHTED_ROUND_ROBIN` worker choice strategy (experimental).
 455
 456 ### Changed
 457
 458 - Renamed worker choice strategy `LESS_BUSY` to `LEAST_BUSY` and `LESS_USED` to `LEAST_USED`.
 459
 460 ## [2.4.14] - 2023-05-09
 461
 462 ### Fixed
 463
 464 - Ensure no undefined task runtime can land in the tasks history.
 465 - Fix median computation implementation once again.
 466
 467 ### Added
 468
 469 - Unit tests for median and queue implementations.
 470
 471 ## [2.4.13] - 2023-05-08
 472
 473 ### Fixed
 474
 475 - Fix worker choice strategy options validation.
 476 - Fix fair share worker choice strategy internals update: ensure virtual task end timestamp is computed at task submission.
 477
 478 ## [2.4.12] - 2023-05-06
 479
 480 ### Added
 481
 482 - Support multiple task functions per worker.
 483 - Add custom worker weights support to worker choice strategies options.
 484
 485 ### Changed
 486
 487 - Use O(1) queue implementation for tasks queueing.
 488
 489 ### Fixed
 490
 491 - Fix median computation implementation.
 492 - Fix fair share worker choice strategy internals update.
 493
 494 ## [2.4.11] - 2023-04-23
 495
 496 ### Changed
 497
 498 - Optimize free worker finding in worker choice strategies.
 499
 500 ## [2.4.10] - 2023-04-15
 501
 502 ### Fixed
 503
 504 - Fix typescript type definition for task function: ensure the input data is optional.
 505 - Fix typescript type definition for pool execute(): ensure the input data is optional.
 506
 507 ## [2.4.9] - 2023-04-15
 508
 509 ### Added
 510
 511 - Add tasks queue enablement runtime setter to pool.
 512 - Add tasks queue options runtime setter to pool.
 513 - Add worker choice strategy options runtime setter to pool.
 514
 515 ### Changed
 516
 517 - Remove the tasks queuing experimental status.
 518
 519 ### Fixed
 520
 521 - Fix task function type definition and validation.
 522 - Fix worker choice strategy options handling.
 523
 524 ## [2.4.8] - 2023-04-12
 525
 526 ### Fixed
 527
 528 - Fix message between main worker and worker type definition for tasks.
 529 - Fix code documentation.
 530
 531 ## [2.4.7] - 2023-04-11
 532
 533 ### Added
 534
 535 - Add worker tasks queue options to pool options.
 536
 537 ### Fixed
 538
 539 - Fix missing documentation.
 540
 541 ## [2.4.6] - 2023-04-10
 542
 543 ### Fixed
 544
 545 - Ensure one task at a time is executed per worker with tasks queueing enabled.
 546 - Properly count worker executing tasks with tasks queueing enabled.
 547
 548 ## [2.4.5] - 2023-04-09
 549
 550 ### Added
 551
 552 - Use monotonic high resolution timer for worker tasks runtime.
 553 - Add worker tasks median runtime to statistics.
 554 - Add worker tasks queue (experimental).
 555
 556 ## [2.4.4] - 2023-04-07
 557
 558 ### Added
 559
 560 - Add `PoolEvents` enumeration and `PoolEvent` type.
 561
 562 ### Fixed
 563
 564 - Destroy worker only on alive check.
 565
 566 ## [2.4.3] - 2023-04-07
 567
 568 ### Fixed
 569
 570 - Fix typedoc generation with inheritance.
 571
 572 ## [2.4.2] - 2023-04-06
 573
 574 ### Added
 575
 576 - Add `full` event to dynamic pool.
 577 - Keep worker choice strategy in memory for conditional reuse.
 578
 579 ### Fixed
 580
 581 - Fix possible negative worker key at worker removal in worker choice strategies.
 582
 583 ## [2.4.1] - 2023-04-05
 584
 585 ### Changed
 586
 587 - Optimize worker choice strategy for dynamic pool.
 588
 589 ### Fixed
 590
 591 - Ensure dynamic pool does not alter worker choice strategy expected behavior.
 592
 593 ## [2.4.0] - 2023-04-04
 594
 595 ### Added
 596
 597 - Add `LESS_BUSY` worker choice strategy.
 598
 599 ### Changed
 600
 601 - Optimize worker storage in pool.
 602 - Optimize worker alive status check.
 603 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 604 - Optimize `LESS_USED` worker choice strategy.
 605 - Update benchmarks versus external threads pools.
 606 - Optimize tasks usage statistics requirements for worker choice strategy.
 607
 608 ### Fixed
 609
 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.
 613 - Fix package publication with pnpm.
 614
 615 ## [2.4.0-3] - 2023-04-04
 616
 617 ### Added
 618
 619 - Add `LESS_BUSY` worker choice strategy.
 620
 621 ### Changed
 622
 623 - Optimize worker storage in pool.
 624 - Optimize worker alive status check.
 625 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 626 - Optimize `LESS_USED` worker choice strategy.
 627 - Update benchmarks versus external threads pools.
 628
 629 ### Fixed
 630
 631 - Ensure trimmable characters are checked at pool initialization.
 632 - Fix message id integer overflow.
 633 - Fix pool worker removal in worker choice strategy internals.
 634 - Fix package publication with pnpm.
 635
 636 ## [2.4.0-2] - 2023-04-03
 637
 638 ### Added
 639
 640 - Add `LESS_BUSY` worker choice strategy.
 641
 642 ### Changed
 643
 644 - Optimize worker storage in pool.
 645 - Optimize worker alive status check.
 646 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 647 - Optimize `LESS_USED` worker choice strategy.
 648
 649 ### Fixed
 650
 651 - Ensure trimmable characters are checked at pool initialization.
 652 - Fix message id integer overflow.
 653 - Fix pool worker removal in worker choice strategy internals.
 654 - Fix package publication with pnpm.
 655
 656 ## [2.4.0-1] - 2023-04-03
 657
 658 ### Added
 659
 660 - Add `LESS_BUSY` worker choice strategy.
 661
 662 ### Changed
 663
 664 - Optimize worker storage in pool.
 665 - Optimize worker alive status check.
 666 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 667 - Optimize `LESS_USED` worker choice strategy.
 668
 669 ### Fixed
 670
 671 - Ensure trimmable characters are checked at pool initialization.
 672 - Fix message id integer overflow.
 673 - Fix pool worker removal in worker choice strategy internals.
 674
 675 ## [2.4.0-0] - 2023-04-03
 676
 677 ### Added
 678
 679 - Add `LESS_BUSY` worker choice strategy.
 680
 681 ### Changed
 682
 683 - Optimize worker storage in pool.
 684 - Optimize worker alive status check.
 685 - BREAKING CHANGE: Rename worker choice strategy `LESS_RECENTLY_USED` to `LESS_USED`.
 686 - Optimize `LESS_USED` worker choice strategy.
 687
 688 ### Fixed
 689
 690 - Ensure trimmable characters are checked at pool initialization.
 691 - Fix message id integer overflow.
 692 - Fix pool worker removal in worker choice strategy internals.
 693
 694 ## [2.3.10] - 2023-03-18
 695
 696 ### Fixed
 697
 698 - Fix package.json `exports` syntax for ESM and CommonJS.
 699
 700 ### Changed
 701
 702 - Permit SemVer pre-release publication.
 703
 704 ## [2.3.10-2] - 2023-03-18
 705
 706 ### Fixed
 707
 708 - Fix package.json `exports` syntax for ESM and CommonJS.
 709
 710 ## [2.3.10-1] - 2023-03-18
 711
 712 ### Changed
 713
 714 - Permit SemVer pre-release publication.
 715
 716 ## [2.3.10-0] - 2023-03-18
 717
 718 ### Fixed
 719
 720 - Fix package.json `exports` syntax for ESM and CommonJS.
 721
 722 ## [2.3.9] - 2023-03-18
 723
 724 ### Changed
 725
 726 - Introduce ESM module support along with CommonJS one.
 727
 728 ### Fixed
 729
 730 - Fix brown paper bag bug referencing the same object literal.
 731
 732 ## [2.3.8] - 2023-03-18
 733
 734 ### Changed
 735
 736 - Switch internal benchmarking code to benny.
 737 - Switch to TypeScript 5.x.x.
 738 - Switch rollup bundler plugins to core ones.
 739 - Switch to TSDoc syntax.
 740 - Enforce conventional commits.
 741
 742 ### Fixed
 743
 744 - Fix random integer generator.
 745 - Fix worker choice strategy pool type identification at initialization.
 746
 747 ## [2.3.7] - 2022-10-23
 748
 749 ### Changed
 750
 751 - Switch to open collective FOSS project funding platform.
 752 - Switch to ts-standard linter configuration on TypeScript code.
 753
 754 ### Fixed
 755
 756 - Fixed missing async on pool execute method.
 757 - Fixed typing in TypeScript example.
 758 - Fixed types in unit tests.
 759
 760 ## [2.3.6] - 2022-10-22
 761
 762 ### Changed
 763
 764 - Cleanup pool attributes and methods.
 765 - Refine error types thrown.
 766
 767 ### Fixed
 768
 769 - Fix continuous integration build on windows.
 770 - Fix code coverage reporting by using c8 instead of nyc.
 771
 772 ## [2.3.5] - 2022-10-21
 773
 774 ### Changed
 775
 776 - Improve benchmarks: add IO intensive task workload, add task size option, integrate code into linter.
 777 - Optimize tasks usage lookup implementation.
 778
 779 ### Fixed
 780
 781 - Fix missed pool event emitter type export.
 782 - Fix typedoc documentation generation.
 783
 784 ## [2.3.4] - 2022-10-17
 785
 786 ### Added
 787
 788 - Fully automate release process with release-it.
 789
 790 ### Changed
 791
 792 - Optimize fair share task scheduling algorithm implementation.
 793 - Update benchmarks versus external pools results with latest version.
 794
 795 ## [2.3.3] - 2022-10-15
 796
 797 ### Added
 798
 799 - Add support for [cluster settings](https://nodejs.org/api/cluster.html#cluster_cluster_settings) in cluster pool options.
 800
 801 ## [2.3.2] - 2022-10-14
 802
 803 ### Changed
 804
 805 - Optimize fair share worker selection strategy implementation.
 806
 807 ### Fixed
 808
 809 - Fix WRR worker selection strategy: ensure the condition triggering the round robin can be fulfilled.
 810
 811 ## [2.3.1] - 2022-10-13
 812
 813 ### Added
 814
 815 - Pool worker choice strategies:
 816   - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN` strategy based on weighted round robin scheduling algorithm using tasks execution time for now.
 817   - `WorkerChoiceStrategies.FAIR_SHARE` strategy based on fair share scheduling algorithm using tasks execution time for now.
 818
 819 ## [2.2.2] - 2022-10-09
 820
 821 ### Fixed
 822
 823 - Fixed `README.md` file.
 824
 825 ## [2.2.1] - 2022-10-08
 826
 827 ### Added
 828
 829 - Dynamic worker choice strategy change at runtime.
 830
 831 ## [2.2.0] - 2022-01-05
 832
 833 ### Breaking Changes
 834
 835 - Support only Node.js version 16.x.x for cluster pool: upstream cluster API have changed on that version.
 836
 837 ## [2.1.0] - 2021-08-29
 838
 839 ### Added
 840
 841 - Add an optional pool option `messageHandler` to `PoolOptions<Worker>` for registering a message handler callback on each worker.
 842
 843 ### Breaking Changes
 844
 845 - `AbstractWorker` class `maxInactiveTime`, `killBehavior` and `async` attributes have been removed in favour of the same ones in the worker options `opts` public attribute.
 846 - `AbstractWorker` class `lastTask` attribute have been renamed to `lastTaskTimestamp`.
 847 - `AbstractWorker` class `interval` attribute have been renamed to `aliveInterval`.
 848 - `AbstractWorker` class cannot be instantiated without specifying the `mainWorker` argument referencing the main worker.
 849
 850 ## [2.0.2] - 2021-05-12
 851
 852 ### Bug fixes
 853
 854 - Fix `busy` event emission on fixed pool type
 855
 856 ## [2.0.1] - 2021-03-16
 857
 858 ### Bug fixes
 859
 860 - Check if pool options are properly set.
 861 - `busy` event is emitted on all pool types.
 862
 863 ## [2.0.0] - 2021-03-01
 864
 865 ### Bug fixes
 866
 867 - Now a thread/process by default is not deleted when the task submitted take more time than maxInactiveTime configured (issue #70).
 868
 869 ### Breaking Changes
 870
 871 - `FullPool` event is now renamed to `busy`.
 872 - `maxInactiveTime` on `ThreadWorker` default behavior is now changed, if you want to keep the old behavior set `killBehavior` to `KillBehaviors.HARD`.
 873   _Find more details on our JSDoc._
 874
 875 - `maxTasks` option on `FixedThreadPool` and `DynamicThreadPool` is now removed since is no more needed.
 876
 877 - We changed some internal structures, but you shouldn't be too affected by them as these are internal changes.
 878
 879 ### Pool options types declaration merge
 880
 881 `FixedThreadPoolOptions` and `DynamicThreadPoolOptions` type declarations have been merged to `PoolOptions<Worker>`.
 882
 883 #### New `export` strategy
 884
 885 ```js
 886 // Before
 887 const DynamicThreadPool = require('poolifier/lib/dynamic')
 888 // After
 889 const { DynamicThreadPool } = require('poolifier/lib/dynamic')
 890 ```
 891
 892 But you should always prefer just using
 893
 894 ```js
 895 const { DynamicThreadPool } = require('poolifier')
 896 ```
 897
 898 #### New type definitions for input data and response
 899
 900 For cluster worker and worker-thread pools, you can now only send and receive structured-cloneable data.
 901 _This is not a limitation by poolifier but Node.js._
 902
 903 #### Public property replacements
 904
 905 `numWorkers` property is now `numberOfWorkers`
 906
 907 #### Internal (protected) properties and methods renaming
 908
 909 These properties are not intended for end users
 910
 911 - `id` => `nextMessageId`
 912
 913 These methods are not intended for end users
 914
 915 - `_chooseWorker` => `chooseWorker`
 916 - `_newWorker` => `createWorker`
 917 - `_execute` => `internalExecute`
 918 - `_chooseWorker` => `chooseWorker`
 919 - `_checkAlive` => `checkAlive`
 920 - `_run` => `run`
 921 - `_runAsync` => `runAsync`
 922
 923 ## [1.1.0] - 2020-05-21
 924
 925 ### Added
 926
 927 - ThreadWorker support async functions as option
 928 - Various external library patches
 929
 930 ## [1.0.0] - 2020-01-24
 931
 932 ### Added
 933
 934 - FixedThreadPool implementation
 935 - DynamicThreadPool implementation
 936 - WorkerThread implementation to improve developer experience