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