tests/pools/abstract/abstract-pool.test.js

   1 const { expect } = require('expect')
   2 const {
   3   DynamicClusterPool,
   4   DynamicThreadPool,
   5   FixedClusterPool,
   6   FixedThreadPool,
   7   PoolEvents,
   8   WorkerChoiceStrategies,
   9   PoolTypes,
  10   WorkerTypes
  11 } = require('../../../lib')
  12 const { CircularArray } = require('../../../lib/circular-array')
  13 const { Queue } = require('../../../lib/queue')
  14
  15 describe('Abstract pool test suite', () => {
  16   const numberOfWorkers = 2
  17   class StubPoolWithRemoveAllWorker extends FixedThreadPool {
  18     removeAllWorker () {
  19       this.workerNodes = []
  20       this.promiseResponseMap.clear()
  21     }
  22   }
  23   class StubPoolWithIsMain extends FixedThreadPool {
  24     isMain () {
  25       return false
  26     }
  27   }
  28
  29   it('Simulate pool creation from a non main thread/process', () => {
  30     expect(
  31       () =>
  32         new StubPoolWithIsMain(
  33           numberOfWorkers,
  34           './tests/worker-files/thread/testWorker.js',
  35           {
  36             errorHandler: e => console.error(e)
  37           }
  38         )
  39     ).toThrowError('Cannot start a pool from a worker!')
  40   })
  41
  42   it('Verify that filePath is checked', () => {
  43     const expectedError = new Error(
  44       'Please specify a file with a worker implementation'
  45     )
  46     expect(() => new FixedThreadPool(numberOfWorkers)).toThrowError(
  47       expectedError
  48     )
  49     expect(() => new FixedThreadPool(numberOfWorkers, '')).toThrowError(
  50       expectedError
  51     )
  52   })
  53
  54   it('Verify that numberOfWorkers is checked', () => {
  55     expect(() => new FixedThreadPool()).toThrowError(
  56       'Cannot instantiate a pool without specifying the number of workers'
  57     )
  58   })
  59
  60   it('Verify that a negative number of workers is checked', () => {
  61     expect(
  62       () =>
  63         new FixedClusterPool(-1, './tests/worker-files/cluster/testWorker.js')
  64     ).toThrowError(
  65       new RangeError(
  66         'Cannot instantiate a pool with a negative number of workers'
  67       )
  68     )
  69   })
  70
  71   it('Verify that a non integer number of workers is checked', () => {
  72     expect(
  73       () =>
  74         new FixedThreadPool(0.25, './tests/worker-files/thread/testWorker.js')
  75     ).toThrowError(
  76       new TypeError(
  77         'Cannot instantiate a pool with a non safe integer number of workers'
  78       )
  79     )
  80   })
  81
  82   it('Verify that pool options are checked', async () => {
  83     let pool = new FixedThreadPool(
  84       numberOfWorkers,
  85       './tests/worker-files/thread/testWorker.js'
  86     )
  87     expect(pool.emitter).toBeDefined()
  88     expect(pool.opts.enableEvents).toBe(true)
  89     expect(pool.opts.restartWorkerOnError).toBe(true)
  90     expect(pool.opts.enableTasksQueue).toBe(false)
  91     expect(pool.opts.tasksQueueOptions).toBeUndefined()
  92     expect(pool.opts.workerChoiceStrategy).toBe(
  93       WorkerChoiceStrategies.ROUND_ROBIN
  94     )
  95     expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
  96       runTime: { median: false },
  97       waitTime: { median: false },
  98       elu: { median: false }
  99     })
 100     expect(pool.opts.messageHandler).toBeUndefined()
 101     expect(pool.opts.errorHandler).toBeUndefined()
 102     expect(pool.opts.onlineHandler).toBeUndefined()
 103     expect(pool.opts.exitHandler).toBeUndefined()
 104     await pool.destroy()
 105     const testHandler = () => console.log('test handler executed')
 106     pool = new FixedThreadPool(
 107       numberOfWorkers,
 108       './tests/worker-files/thread/testWorker.js',
 109       {
 110         workerChoiceStrategy: WorkerChoiceStrategies.LEAST_USED,
 111         workerChoiceStrategyOptions: {
 112           runTime: { median: true },
 113           weights: { 0: 300, 1: 200 }
 114         },
 115         enableEvents: false,
 116         restartWorkerOnError: false,
 117         enableTasksQueue: true,
 118         tasksQueueOptions: { concurrency: 2 },
 119         messageHandler: testHandler,
 120         errorHandler: testHandler,
 121         onlineHandler: testHandler,
 122         exitHandler: testHandler
 123       }
 124     )
 125     expect(pool.emitter).toBeUndefined()
 126     expect(pool.opts.enableEvents).toBe(false)
 127     expect(pool.opts.restartWorkerOnError).toBe(false)
 128     expect(pool.opts.enableTasksQueue).toBe(true)
 129     expect(pool.opts.tasksQueueOptions).toStrictEqual({ concurrency: 2 })
 130     expect(pool.opts.workerChoiceStrategy).toBe(
 131       WorkerChoiceStrategies.LEAST_USED
 132     )
 133     expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
 134       runTime: { median: true },
 135       weights: { 0: 300, 1: 200 }
 136     })
 137     expect(pool.opts.messageHandler).toStrictEqual(testHandler)
 138     expect(pool.opts.errorHandler).toStrictEqual(testHandler)
 139     expect(pool.opts.onlineHandler).toStrictEqual(testHandler)
 140     expect(pool.opts.exitHandler).toStrictEqual(testHandler)
 141     await pool.destroy()
 142   })
 143
 144   it('Verify that pool options are validated', async () => {
 145     expect(
 146       () =>
 147         new FixedThreadPool(
 148           numberOfWorkers,
 149           './tests/worker-files/thread/testWorker.js',
 150           {
 151             workerChoiceStrategy: 'invalidStrategy'
 152           }
 153         )
 154     ).toThrowError("Invalid worker choice strategy 'invalidStrategy'")
 155     expect(
 156       () =>
 157         new FixedThreadPool(
 158           numberOfWorkers,
 159           './tests/worker-files/thread/testWorker.js',
 160           {
 161             workerChoiceStrategyOptions: 'invalidOptions'
 162           }
 163         )
 164     ).toThrowError(
 165       'Invalid worker choice strategy options: must be a plain object'
 166     )
 167     expect(
 168       () =>
 169         new FixedThreadPool(
 170           numberOfWorkers,
 171           './tests/worker-files/thread/testWorker.js',
 172           {
 173             workerChoiceStrategyOptions: { weights: {} }
 174           }
 175         )
 176     ).toThrowError(
 177       'Invalid worker choice strategy options: must have a weight for each worker node'
 178     )
 179     expect(
 180       () =>
 181         new FixedThreadPool(
 182           numberOfWorkers,
 183           './tests/worker-files/thread/testWorker.js',
 184           {
 185             workerChoiceStrategyOptions: { measurement: 'invalidMeasurement' }
 186           }
 187         )
 188     ).toThrowError(
 189       "Invalid worker choice strategy options: invalid measurement 'invalidMeasurement'"
 190     )
 191     expect(
 192       () =>
 193         new FixedThreadPool(
 194           numberOfWorkers,
 195           './tests/worker-files/thread/testWorker.js',
 196           {
 197             enableTasksQueue: true,
 198             tasksQueueOptions: { concurrency: 0 }
 199           }
 200         )
 201     ).toThrowError("Invalid worker tasks concurrency '0'")
 202     expect(
 203       () =>
 204         new FixedThreadPool(
 205           numberOfWorkers,
 206           './tests/worker-files/thread/testWorker.js',
 207           {
 208             enableTasksQueue: true,
 209             tasksQueueOptions: 'invalidTasksQueueOptions'
 210           }
 211         )
 212     ).toThrowError('Invalid tasks queue options: must be a plain object')
 213     expect(
 214       () =>
 215         new FixedThreadPool(
 216           numberOfWorkers,
 217           './tests/worker-files/thread/testWorker.js',
 218           {
 219             enableTasksQueue: true,
 220             tasksQueueOptions: { concurrency: 0.2 }
 221           }
 222         )
 223     ).toThrowError('Invalid worker tasks concurrency: must be an integer')
 224   })
 225
 226   it('Verify that worker choice strategy options can be set', async () => {
 227     const pool = new FixedThreadPool(
 228       numberOfWorkers,
 229       './tests/worker-files/thread/testWorker.js',
 230       { workerChoiceStrategy: WorkerChoiceStrategies.FAIR_SHARE }
 231     )
 232     expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
 233       runTime: { median: false },
 234       waitTime: { median: false },
 235       elu: { median: false }
 236     })
 237     for (const [, workerChoiceStrategy] of pool.workerChoiceStrategyContext
 238       .workerChoiceStrategies) {
 239       expect(workerChoiceStrategy.opts).toStrictEqual({
 240         runTime: { median: false },
 241         waitTime: { median: false },
 242         elu: { median: false }
 243       })
 244     }
 245     expect(
 246       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
 247     ).toStrictEqual({
 248       runTime: {
 249         aggregate: true,
 250         average: true,
 251         median: false
 252       },
 253       waitTime: {
 254         aggregate: false,
 255         average: false,
 256         median: false
 257       },
 258       elu: {
 259         aggregate: true,
 260         average: true,
 261         median: false
 262       }
 263     })
 264     pool.setWorkerChoiceStrategyOptions({
 265       runTime: { median: true },
 266       elu: { median: true }
 267     })
 268     expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
 269       runTime: { median: true },
 270       elu: { median: true }
 271     })
 272     for (const [, workerChoiceStrategy] of pool.workerChoiceStrategyContext
 273       .workerChoiceStrategies) {
 274       expect(workerChoiceStrategy.opts).toStrictEqual({
 275         runTime: { median: true },
 276         elu: { median: true }
 277       })
 278     }
 279     expect(
 280       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
 281     ).toStrictEqual({
 282       runTime: {
 283         aggregate: true,
 284         average: false,
 285         median: true
 286       },
 287       waitTime: {
 288         aggregate: false,
 289         average: false,
 290         median: false
 291       },
 292       elu: {
 293         aggregate: true,
 294         average: false,
 295         median: true
 296       }
 297     })
 298     pool.setWorkerChoiceStrategyOptions({
 299       runTime: { median: false },
 300       elu: { median: false }
 301     })
 302     expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
 303       runTime: { median: false },
 304       elu: { median: false }
 305     })
 306     for (const [, workerChoiceStrategy] of pool.workerChoiceStrategyContext
 307       .workerChoiceStrategies) {
 308       expect(workerChoiceStrategy.opts).toStrictEqual({
 309         runTime: { median: false },
 310         elu: { median: false }
 311       })
 312     }
 313     expect(
 314       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
 315     ).toStrictEqual({
 316       runTime: {
 317         aggregate: true,
 318         average: true,
 319         median: false
 320       },
 321       waitTime: {
 322         aggregate: false,
 323         average: false,
 324         median: false
 325       },
 326       elu: {
 327         aggregate: true,
 328         average: true,
 329         median: false
 330       }
 331     })
 332     await pool.destroy()
 333   })
 334
 335   it('Verify that tasks queue can be enabled/disabled', async () => {
 336     const pool = new FixedThreadPool(
 337       numberOfWorkers,
 338       './tests/worker-files/thread/testWorker.js'
 339     )
 340     expect(pool.opts.enableTasksQueue).toBe(false)
 341     expect(pool.opts.tasksQueueOptions).toBeUndefined()
 342     pool.enableTasksQueue(true)
 343     expect(pool.opts.enableTasksQueue).toBe(true)
 344     expect(pool.opts.tasksQueueOptions).toStrictEqual({ concurrency: 1 })
 345     pool.enableTasksQueue(true, { concurrency: 2 })
 346     expect(pool.opts.enableTasksQueue).toBe(true)
 347     expect(pool.opts.tasksQueueOptions).toStrictEqual({ concurrency: 2 })
 348     pool.enableTasksQueue(false)
 349     expect(pool.opts.enableTasksQueue).toBe(false)
 350     expect(pool.opts.tasksQueueOptions).toBeUndefined()
 351     await pool.destroy()
 352   })
 353
 354   it('Verify that tasks queue options can be set', async () => {
 355     const pool = new FixedThreadPool(
 356       numberOfWorkers,
 357       './tests/worker-files/thread/testWorker.js',
 358       { enableTasksQueue: true }
 359     )
 360     expect(pool.opts.tasksQueueOptions).toStrictEqual({ concurrency: 1 })
 361     pool.setTasksQueueOptions({ concurrency: 2 })
 362     expect(pool.opts.tasksQueueOptions).toStrictEqual({ concurrency: 2 })
 363     expect(() =>
 364       pool.setTasksQueueOptions('invalidTasksQueueOptions')
 365     ).toThrowError('Invalid tasks queue options: must be a plain object')
 366     expect(() => pool.setTasksQueueOptions({ concurrency: 0 })).toThrowError(
 367       "Invalid worker tasks concurrency '0'"
 368     )
 369     expect(() => pool.setTasksQueueOptions({ concurrency: 0.2 })).toThrowError(
 370       'Invalid worker tasks concurrency: must be an integer'
 371     )
 372     await pool.destroy()
 373   })
 374
 375   it('Verify that pool info is set', async () => {
 376     let pool = new FixedThreadPool(
 377       numberOfWorkers,
 378       './tests/worker-files/thread/testWorker.js'
 379     )
 380     expect(pool.info).toStrictEqual({
 381       type: PoolTypes.fixed,
 382       worker: WorkerTypes.thread,
 383       minSize: numberOfWorkers,
 384       maxSize: numberOfWorkers,
 385       workerNodes: numberOfWorkers,
 386       idleWorkerNodes: numberOfWorkers,
 387       busyWorkerNodes: 0,
 388       executedTasks: 0,
 389       executingTasks: 0,
 390       queuedTasks: 0,
 391       maxQueuedTasks: 0,
 392       failedTasks: 0
 393     })
 394     await pool.destroy()
 395     pool = new DynamicClusterPool(
 396       numberOfWorkers,
 397       numberOfWorkers * 2,
 398       './tests/worker-files/thread/testWorker.js'
 399     )
 400     expect(pool.info).toStrictEqual({
 401       type: PoolTypes.dynamic,
 402       worker: WorkerTypes.cluster,
 403       minSize: numberOfWorkers,
 404       maxSize: numberOfWorkers * 2,
 405       workerNodes: numberOfWorkers,
 406       idleWorkerNodes: numberOfWorkers,
 407       busyWorkerNodes: 0,
 408       executedTasks: 0,
 409       executingTasks: 0,
 410       queuedTasks: 0,
 411       maxQueuedTasks: 0,
 412       failedTasks: 0
 413     })
 414     await pool.destroy()
 415   })
 416
 417   it('Simulate worker not found', async () => {
 418     const pool = new StubPoolWithRemoveAllWorker(
 419       numberOfWorkers,
 420       './tests/worker-files/cluster/testWorker.js',
 421       {
 422         errorHandler: e => console.error(e)
 423       }
 424     )
 425     expect(pool.workerNodes.length).toBe(numberOfWorkers)
 426     // Simulate worker not found.
 427     pool.removeAllWorker()
 428     expect(pool.workerNodes.length).toBe(0)
 429     await pool.destroy()
 430   })
 431
 432   it('Verify that worker pool tasks usage are initialized', async () => {
 433     const pool = new FixedClusterPool(
 434       numberOfWorkers,
 435       './tests/worker-files/cluster/testWorker.js'
 436     )
 437     for (const workerNode of pool.workerNodes) {
 438       expect(workerNode.workerUsage).toStrictEqual({
 439         tasks: {
 440           executed: 0,
 441           executing: 0,
 442           queued: 0,
 443           failed: 0
 444         },
 445         runTime: {
 446           aggregate: 0,
 447           average: 0,
 448           median: 0,
 449           history: expect.any(CircularArray)
 450         },
 451         waitTime: {
 452           aggregate: 0,
 453           average: 0,
 454           median: 0,
 455           history: expect.any(CircularArray)
 456         },
 457         elu: {
 458           idle: {
 459             aggregate: 0,
 460             average: 0,
 461             median: 0,
 462             history: expect.any(CircularArray)
 463           },
 464           active: {
 465             aggregate: 0,
 466             average: 0,
 467             median: 0,
 468             history: expect.any(CircularArray)
 469           },
 470           utilization: 0
 471         }
 472       })
 473     }
 474     await pool.destroy()
 475   })
 476
 477   it('Verify that worker pool tasks queue are initialized', async () => {
 478     const pool = new FixedClusterPool(
 479       numberOfWorkers,
 480       './tests/worker-files/cluster/testWorker.js'
 481     )
 482     for (const workerNode of pool.workerNodes) {
 483       expect(workerNode.tasksQueue).toBeDefined()
 484       expect(workerNode.tasksQueue).toBeInstanceOf(Queue)
 485       expect(workerNode.tasksQueue.size).toBe(0)
 486     }
 487     await pool.destroy()
 488   })
 489
 490   it('Verify that worker pool tasks usage are computed', async () => {
 491     const pool = new FixedClusterPool(
 492       numberOfWorkers,
 493       './tests/worker-files/cluster/testWorker.js'
 494     )
 495     const promises = new Set()
 496     const maxMultiplier = 2
 497     for (let i = 0; i < numberOfWorkers * maxMultiplier; i++) {
 498       promises.add(pool.execute())
 499     }
 500     for (const workerNode of pool.workerNodes) {
 501       expect(workerNode.workerUsage).toStrictEqual({
 502         tasks: {
 503           executed: 0,
 504           executing: maxMultiplier,
 505           queued: 0,
 506           failed: 0
 507         },
 508         runTime: {
 509           aggregate: 0,
 510           average: 0,
 511           median: 0,
 512           history: expect.any(CircularArray)
 513         },
 514         waitTime: {
 515           aggregate: 0,
 516           average: 0,
 517           median: 0,
 518           history: expect.any(CircularArray)
 519         },
 520         elu: {
 521           idle: {
 522             aggregate: 0,
 523             average: 0,
 524             median: 0,
 525             history: expect.any(CircularArray)
 526           },
 527           active: {
 528             aggregate: 0,
 529             average: 0,
 530             median: 0,
 531             history: expect.any(CircularArray)
 532           },
 533           utilization: 0
 534         }
 535       })
 536     }
 537     await Promise.all(promises)
 538     for (const workerNode of pool.workerNodes) {
 539       expect(workerNode.workerUsage).toStrictEqual({
 540         tasks: {
 541           executed: maxMultiplier,
 542           executing: 0,
 543           queued: 0,
 544           failed: 0
 545         },
 546         runTime: {
 547           aggregate: 0,
 548           average: 0,
 549           median: 0,
 550           history: expect.any(CircularArray)
 551         },
 552         waitTime: {
 553           aggregate: 0,
 554           average: 0,
 555           median: 0,
 556           history: expect.any(CircularArray)
 557         },
 558         elu: {
 559           idle: {
 560             aggregate: 0,
 561             average: 0,
 562             median: 0,
 563             history: expect.any(CircularArray)
 564           },
 565           active: {
 566             aggregate: 0,
 567             average: 0,
 568             median: 0,
 569             history: expect.any(CircularArray)
 570           },
 571           utilization: 0
 572         }
 573       })
 574     }
 575     await pool.destroy()
 576   })
 577
 578   it('Verify that worker pool tasks usage are reset at worker choice strategy change', async () => {
 579     const pool = new DynamicThreadPool(
 580       numberOfWorkers,
 581       numberOfWorkers,
 582       './tests/worker-files/thread/testWorker.js'
 583     )
 584     const promises = new Set()
 585     const maxMultiplier = 2
 586     for (let i = 0; i < numberOfWorkers * maxMultiplier; i++) {
 587       promises.add(pool.execute())
 588     }
 589     await Promise.all(promises)
 590     for (const workerNode of pool.workerNodes) {
 591       expect(workerNode.workerUsage).toStrictEqual({
 592         tasks: {
 593           executed: expect.any(Number),
 594           executing: 0,
 595           queued: 0,
 596           failed: 0
 597         },
 598         runTime: {
 599           aggregate: 0,
 600           average: 0,
 601           median: 0,
 602           history: expect.any(CircularArray)
 603         },
 604         waitTime: {
 605           aggregate: 0,
 606           average: 0,
 607           median: 0,
 608           history: expect.any(CircularArray)
 609         },
 610         elu: {
 611           idle: {
 612             aggregate: 0,
 613             average: 0,
 614             median: 0,
 615             history: expect.any(CircularArray)
 616           },
 617           active: {
 618             aggregate: 0,
 619             average: 0,
 620             median: 0,
 621             history: expect.any(CircularArray)
 622           },
 623           utilization: 0
 624         }
 625       })
 626       expect(workerNode.workerUsage.tasks.executed).toBeGreaterThan(0)
 627       expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
 628         maxMultiplier
 629       )
 630     }
 631     pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.FAIR_SHARE)
 632     for (const workerNode of pool.workerNodes) {
 633       expect(workerNode.workerUsage).toStrictEqual({
 634         tasks: {
 635           executed: 0,
 636           executing: 0,
 637           queued: 0,
 638           failed: 0
 639         },
 640         runTime: {
 641           aggregate: 0,
 642           average: 0,
 643           median: 0,
 644           history: expect.any(CircularArray)
 645         },
 646         waitTime: {
 647           aggregate: 0,
 648           average: 0,
 649           median: 0,
 650           history: expect.any(CircularArray)
 651         },
 652         elu: {
 653           idle: {
 654             aggregate: 0,
 655             average: 0,
 656             median: 0,
 657             history: expect.any(CircularArray)
 658           },
 659           active: {
 660             aggregate: 0,
 661             average: 0,
 662             median: 0,
 663             history: expect.any(CircularArray)
 664           },
 665           utilization: 0
 666         }
 667       })
 668       expect(workerNode.workerUsage.runTime.history.length).toBe(0)
 669       expect(workerNode.workerUsage.waitTime.history.length).toBe(0)
 670     }
 671     await pool.destroy()
 672   })
 673
 674   it("Verify that pool event emitter 'full' event can register a callback", async () => {
 675     const pool = new DynamicThreadPool(
 676       numberOfWorkers,
 677       numberOfWorkers,
 678       './tests/worker-files/thread/testWorker.js'
 679     )
 680     const promises = new Set()
 681     let poolFull = 0
 682     let poolInfo
 683     pool.emitter.on(PoolEvents.full, info => {
 684       ++poolFull
 685       poolInfo = info
 686     })
 687     for (let i = 0; i < numberOfWorkers * 2; i++) {
 688       promises.add(pool.execute())
 689     }
 690     await Promise.all(promises)
 691     // The `full` event is triggered when the number of submitted tasks at once reach the max number of workers in the dynamic pool.
 692     // So in total numberOfWorkers * 2 times for a loop submitting up to numberOfWorkers * 2 tasks to the dynamic pool with min = max = numberOfWorkers.
 693     expect(poolFull).toBe(numberOfWorkers * 2)
 694     expect(poolInfo).toStrictEqual({
 695       type: PoolTypes.dynamic,
 696       worker: WorkerTypes.thread,
 697       minSize: expect.any(Number),
 698       maxSize: expect.any(Number),
 699       workerNodes: expect.any(Number),
 700       idleWorkerNodes: expect.any(Number),
 701       busyWorkerNodes: expect.any(Number),
 702       executedTasks: expect.any(Number),
 703       executingTasks: expect.any(Number),
 704       queuedTasks: expect.any(Number),
 705       maxQueuedTasks: expect.any(Number),
 706       failedTasks: expect.any(Number)
 707     })
 708     await pool.destroy()
 709   })
 710
 711   it("Verify that pool event emitter 'busy' event can register a callback", async () => {
 712     const pool = new FixedThreadPool(
 713       numberOfWorkers,
 714       './tests/worker-files/thread/testWorker.js'
 715     )
 716     const promises = new Set()
 717     let poolBusy = 0
 718     let poolInfo
 719     pool.emitter.on(PoolEvents.busy, info => {
 720       ++poolBusy
 721       poolInfo = info
 722     })
 723     for (let i = 0; i < numberOfWorkers * 2; i++) {
 724       promises.add(pool.execute())
 725     }
 726     await Promise.all(promises)
 727     // The `busy` event is triggered when the number of submitted tasks at once reach the number of fixed pool workers.
 728     // So in total numberOfWorkers + 1 times for a loop submitting up to numberOfWorkers * 2 tasks to the fixed pool.
 729     expect(poolBusy).toBe(numberOfWorkers + 1)
 730     expect(poolInfo).toStrictEqual({
 731       type: PoolTypes.fixed,
 732       worker: WorkerTypes.thread,
 733       minSize: expect.any(Number),
 734       maxSize: expect.any(Number),
 735       workerNodes: expect.any(Number),
 736       idleWorkerNodes: expect.any(Number),
 737       busyWorkerNodes: expect.any(Number),
 738       executedTasks: expect.any(Number),
 739       executingTasks: expect.any(Number),
 740       queuedTasks: expect.any(Number),
 741       maxQueuedTasks: expect.any(Number),
 742       failedTasks: expect.any(Number)
 743     })
 744     await pool.destroy()
 745   })
 746
 747   it('Verify that multiple tasks worker is working', async () => {
 748     const pool = new DynamicClusterPool(
 749       numberOfWorkers,
 750       numberOfWorkers * 2,
 751       './tests/worker-files/cluster/testMultiTasksWorker.js'
 752     )
 753     const data = { n: 10 }
 754     const result0 = await pool.execute(data)
 755     expect(result0).toBe(false)
 756     const result1 = await pool.execute(data, 'jsonIntegerSerialization')
 757     expect(result1).toBe(false)
 758     const result2 = await pool.execute(data, 'factorial')
 759     expect(result2).toBe(3628800)
 760     const result3 = await pool.execute(data, 'fibonacci')
 761     expect(result3).toBe(89)
 762   })
 763 })