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