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