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