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