feat: untangle worker choice strategies tasks distribution and dynamic worker creatio...

[poolifier.git] / tests / pools / thread / dynamic.test.js

const { expect } = require('expect')
const { DynamicThreadPool, PoolEvents } = require('../../../lib')
const { TaskFunctions } = require('../../test-types')
const { sleep, waitWorkerEvents } = require('../../test-utils')

describe('Dynamic thread pool test suite', () => {
  const min = 1
  const max = 3
  const pool = new DynamicThreadPool(
    min,
    max,
    './tests/worker-files/thread/testWorker.js',
    {
      errorHandler: (e) => console.error(e)
    }
  )

  it('Verify that the function is executed in a worker thread', async () => {
    let result = await pool.execute({
      function: TaskFunctions.fibonacci
    })
    expect(result).toBe(75025)
    result = await pool.execute({
      function: TaskFunctions.factorial
    })
    expect(result).toBe(9.33262154439441e157)
  })

  it('Verify that new workers are created when required, max size is not exceeded and that after a while new workers will die', async () => {
    let poolBusy = 0
    pool.emitter.on(PoolEvents.busy, () => ++poolBusy)
    for (let i = 0; i < max * 2; i++) {
      pool.execute()
    }
    expect(pool.workerNodes.length).toBeLessThanOrEqual(max)
    expect(pool.workerNodes.length).toBeGreaterThan(min)
    expect(poolBusy).toBe(1)
    const numberOfExitEvents = await waitWorkerEvents(pool, 'exit', max - min)
    expect(numberOfExitEvents).toBe(max - min)
  })

  it('Verify scale thread up and down is working', async () => {
    expect(pool.workerNodes.length).toBe(min)
    for (let i = 0; i < max * 2; i++) {
      pool.execute()
    }
    expect(pool.workerNodes.length).toBe(max)
    await waitWorkerEvents(pool, 'exit', max - min)
    expect(pool.workerNodes.length).toBe(min)
    for (let i = 0; i < max * 2; i++) {
      pool.execute()
    }
    expect(pool.workerNodes.length).toBe(max)
    await waitWorkerEvents(pool, 'exit', max - min)
    expect(pool.workerNodes.length).toBe(min)
  })

  it('Shutdown test', async () => {
    const exitPromise = waitWorkerEvents(pool, 'exit', min)
    let poolDestroy = 0
    pool.emitter.on(PoolEvents.destroy, () => ++poolDestroy)
    await pool.destroy()
    const numberOfExitEvents = await exitPromise
    expect(numberOfExitEvents).toBe(min)
    expect(poolDestroy).toBe(1)
  })

  it('Validation of inputs test', () => {
    expect(() => new DynamicThreadPool(min)).toThrowError(
      'Please specify a file with a worker implementation'
    )
  })

  it('Should work even without opts in input', async () => {
    const pool1 = new DynamicThreadPool(
      min,
      max,
      './tests/worker-files/thread/testWorker.js'
    )
    const res = await pool1.execute()
    expect(res).toStrictEqual({ ok: 1 })
    // We need to clean up the resources after our test
    await pool1.destroy()
  })

  it('Verify scale thread up and down is working when long executing task is used:hard', async () => {
    const longRunningPool = new DynamicThreadPool(
      min,
      max,
      './tests/worker-files/thread/longRunningWorkerHardBehavior.js',
      {
        errorHandler: (e) => console.error(e),
        onlineHandler: () => console.info('long executing worker is online'),
        exitHandler: () => console.info('long executing worker exited')
      }
    )
    expect(longRunningPool.workerNodes.length).toBe(min)
    for (let i = 0; i < max * 2; i++) {
      longRunningPool.execute()
    }
    expect(longRunningPool.workerNodes.length).toBe(max)
    await waitWorkerEvents(longRunningPool, 'exit', max - min)
    expect(longRunningPool.workerNodes.length).toBe(min)
    expect(
      longRunningPool.workerChoiceStrategyContext.workerChoiceStrategies.get(
        longRunningPool.workerChoiceStrategyContext.workerChoiceStrategy
      ).nextWorkerNodeKey
    ).toBeLessThan(longRunningPool.workerNodes.length)
    // We need to clean up the resources after our test
    await longRunningPool.destroy()
  })

  it('Verify scale thread up and down is working when long executing task is used:soft', async () => {
    const longRunningPool = new DynamicThreadPool(
      min,
      max,
      './tests/worker-files/thread/longRunningWorkerSoftBehavior.js',
      {
        errorHandler: (e) => console.error(e),
        onlineHandler: () => console.info('long executing worker is online'),
        exitHandler: () => console.info('long executing worker exited')
      }
    )
    expect(longRunningPool.workerNodes.length).toBe(min)
    for (let i = 0; i < max * 2; i++) {
      longRunningPool.execute()
    }
    expect(longRunningPool.workerNodes.length).toBe(max)
    await sleep(1000)
    // Here we expect the workerNodes to be at the max size since the task is still executing
    expect(longRunningPool.workerNodes.length).toBe(max)
    // We need to clean up the resources after our test
    await longRunningPool.destroy()
  })

  it('Verify that a pool with zero worker can be instantiated', async () => {
    const pool = new DynamicThreadPool(
      0,
      max,
      './tests/worker-files/thread/testWorker.js'
    )
    expect(pool).toBeInstanceOf(DynamicThreadPool)
    // We need to clean up the resources after our test
    await pool.destroy()
  })
})