perf: optimize worker choice strategies

[poolifier.git] / tests / pools / selection-strategies / selection-strategies.test.js

diff --git a/tests/pools/selection-strategies/selection-strategies.test.js b/tests/pools/selection-strategies/selection-strategies.test.js
index d43023b302f3923fc87218cbc8799721ca7026fc..d7567114ed67d35f9288bd1399c327ac6d9911f4 100644 (file)
--- a/tests/pools/selection-strategies/selection-strategies.test.js
+++ b/tests/pools/selection-strategies/selection-strategies.test.js
@@ -15,6 +15,7 @@ describe('Selection strategies test suite', () => {
     expect(WorkerChoiceStrategies.ROUND_ROBIN).toBe('ROUND_ROBIN')
     expect(WorkerChoiceStrategies.LEAST_USED).toBe('LEAST_USED')
     expect(WorkerChoiceStrategies.LEAST_BUSY).toBe('LEAST_BUSY')
+    expect(WorkerChoiceStrategies.LEAST_ELU).toBe('LEAST_ELU')
     expect(WorkerChoiceStrategies.FAIR_SHARE).toBe('FAIR_SHARE')
     expect(WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN).toBe(
       'WEIGHTED_ROUND_ROBIN'
@@ -97,7 +98,7 @@ describe('Selection strategies test suite', () => {
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
-          ).currentWorkerNodeId
+          ).nextWorkerNodeId
         ).toBe(0)
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -114,7 +115,31 @@ describe('Selection strategies test suite', () => {
     await pool.destroy()
   })
 
-  it('Verify ROUND_ROBIN strategy default tasks usage statistics requirements', async () => {
+  it('Verify ROUND_ROBIN strategy default policy', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
+    let pool = new FixedThreadPool(
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: true
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: true
+    })
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify ROUND_ROBIN strategy default tasks statistics requirements', async () => {
     const workerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
     let pool = new FixedThreadPool(
       max,
@@ -134,7 +159,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -156,7 +185,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -195,7 +228,21 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
     }
     expect(
@@ -241,7 +288,21 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
     }
     expect(
@@ -319,7 +380,31 @@ describe('Selection strategies test suite', () => {
     await pool.destroy()
   })
 
-  it('Verify LEAST_USED strategy default tasks usage statistics requirements', async () => {
+  it('Verify LEAST_USED strategy default policy', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.LEAST_USED
+    let pool = new FixedThreadPool(
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: false
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: false
+    })
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify LEAST_USED strategy default tasks statistics requirements', async () => {
     const workerChoiceStrategy = WorkerChoiceStrategies.LEAST_USED
     let pool = new FixedThreadPool(
       max,
@@ -339,7 +424,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -361,7 +450,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -400,7 +493,21 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
     }
     // We need to clean up the resources after our test
@@ -441,15 +548,52 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
     }
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
-  it('Verify LEAST_BUSY strategy default tasks usage statistics requirements', async () => {
+  it('Verify LEAST_BUSY strategy default policy', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.LEAST_BUSY
+    let pool = new FixedThreadPool(
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: false
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: false
+    })
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify LEAST_BUSY strategy default tasks statistics requirements', async () => {
     const workerChoiceStrategy = WorkerChoiceStrategies.LEAST_BUSY
     let pool = new FixedThreadPool(
       max,
@@ -469,7 +613,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -491,7 +639,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -530,9 +682,23 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
-      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThan(0)
       expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
@@ -579,7 +745,21 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
       expect(workerNode.workerUsage.tasks.executed).toBeGreaterThan(0)
       expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
@@ -592,7 +772,232 @@ describe('Selection strategies test suite', () => {
     await pool.destroy()
   })
 
-  it('Verify FAIR_SHARE strategy default tasks usage statistics requirements', async () => {
+  it('Verify LEAST_ELU strategy default policy', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.LEAST_ELU
+    let pool = new FixedThreadPool(
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: false
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: false
+    })
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify LEAST_ELU strategy default tasks statistics requirements', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.LEAST_ELU
+    let pool = new FixedThreadPool(
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+    ).toStrictEqual({
+      runTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: true,
+        average: false,
+        median: false
+      }
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
+    ).toStrictEqual({
+      runTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: true,
+        average: false,
+        median: false
+      }
+    })
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify LEAST_ELU strategy can be run in a fixed pool', async () => {
+    const pool = new FixedThreadPool(
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy: WorkerChoiceStrategies.LEAST_ELU }
+    )
+    // TODO: Create a better test to cover `LeastEluWorkerChoiceStrategy#choose`
+    const promises = new Set()
+    const maxMultiplier = 2
+    for (let i = 0; i < max * maxMultiplier; i++) {
+      promises.add(pool.execute())
+    }
+    await Promise.all(promises)
+    for (const workerNode of pool.workerNodes) {
+      expect(workerNode.workerUsage).toStrictEqual({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          failed: 0
+        },
+        runTime: {
+          aggregate: 0,
+          average: 0,
+          median: 0,
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          aggregate: 0,
+          average: 0,
+          median: 0,
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: expect.any(Number),
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: expect.any(Number)
+        }
+      })
+      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      expect(workerNode.workerUsage.elu.utilization).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.elu.utilization).toBeLessThanOrEqual(1)
+    }
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify LEAST_ELU strategy can be run in a dynamic pool', async () => {
+    const pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy: WorkerChoiceStrategies.LEAST_ELU }
+    )
+    // TODO: Create a better test to cover `LeastEluWorkerChoiceStrategy#choose`
+    const promises = new Set()
+    const maxMultiplier = 2
+    for (let i = 0; i < max * maxMultiplier; i++) {
+      promises.add(pool.execute())
+    }
+    await Promise.all(promises)
+    for (const workerNode of pool.workerNodes) {
+      expect(workerNode.workerUsage).toStrictEqual({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          failed: 0
+        },
+        runTime: {
+          aggregate: 0,
+          average: 0,
+          median: 0,
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          aggregate: 0,
+          average: 0,
+          median: 0,
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: expect.any(Number),
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: expect.any(Number)
+        }
+      })
+      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      expect(workerNode.workerUsage.elu.utilization).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.elu.utilization).toBeLessThanOrEqual(1)
+    }
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify FAIR_SHARE strategy default policy', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.FAIR_SHARE
+    let pool = new FixedThreadPool(
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: false
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: false
+    })
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify FAIR_SHARE strategy default tasks statistics requirements', async () => {
     const workerChoiceStrategy = WorkerChoiceStrategies.FAIR_SHARE
     let pool = new FixedThreadPool(
       max,
@@ -612,7 +1017,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: true,
+        average: true,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -634,7 +1043,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: true,
+        average: true,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -656,7 +1069,7 @@ describe('Selection strategies test suite', () => {
     for (const workerNode of pool.workerNodes) {
       expect(workerNode.workerUsage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
           failed: 0
@@ -673,10 +1086,30 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: expect.any(Number),
+            average: expect.any(Number),
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: expect.any(Number)
+        }
       })
+      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
       expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThan(0)
       expect(workerNode.workerUsage.runTime.average).toBeGreaterThan(0)
+      expect(workerNode.workerUsage.elu.utilization).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.elu.utilization).toBeLessThanOrEqual(1)
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -704,7 +1137,7 @@ describe('Selection strategies test suite', () => {
     for (const workerNode of pool.workerNodes) {
       expect(workerNode.workerUsage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
           failed: 0
@@ -721,10 +1154,30 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: expect.any(Number),
+            average: expect.any(Number),
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: expect.any(Number)
+        }
       })
-      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.runTime.average).toBeGreaterThan(0)
+      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.runTime.average).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.elu.utilization).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.elu.utilization).toBeLessThanOrEqual(1)
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -757,7 +1210,7 @@ describe('Selection strategies test suite', () => {
     for (const workerNode of pool.workerNodes) {
       expect(workerNode.workerUsage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
           failed: 0
@@ -774,10 +1227,30 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: expect.any(Number),
+            average: expect.any(Number),
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: expect.any(Number)
+        }
       })
-      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.runTime.median).toBeGreaterThan(0)
+      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.runTime.median).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.elu.utilization).toBeGreaterThanOrEqual(0)
+      expect(workerNode.workerUsage.elu.utilization).toBeLessThanOrEqual(1)
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -862,7 +1335,31 @@ describe('Selection strategies test suite', () => {
     await pool.destroy()
   })
 
-  it('Verify WEIGHTED_ROUND_ROBIN strategy default tasks usage statistics requirements', async () => {
+  it('Verify WEIGHTED_ROUND_ROBIN strategy default policy', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN
+    let pool = new FixedThreadPool(
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: true
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: true
+    })
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify WEIGHTED_ROUND_ROBIN strategy default tasks statistics requirements', async () => {
     const workerChoiceStrategy = WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN
     let pool = new FixedThreadPool(
       max,
@@ -882,7 +1379,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -904,7 +1405,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -943,7 +1448,21 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
       expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
       expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
@@ -1000,9 +1519,23 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
-      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThan(0)
+      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
       expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
@@ -1062,9 +1595,23 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
-      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThan(0)
+      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
       expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
@@ -1094,7 +1641,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeId
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1110,7 +1657,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1131,7 +1678,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeId
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1147,7 +1694,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1163,7 +1710,32 @@ describe('Selection strategies test suite', () => {
     await pool.destroy()
   })
 
-  it('Verify INTERLEAVED_WEIGHTED_ROUND_ROBIN strategy default tasks usage statistics requirements', async () => {
+  it('Verify INTERLEAVED_WEIGHTED_ROUND_ROBIN strategy default policy', async () => {
+    const workerChoiceStrategy =
+      WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN
+    let pool = new FixedThreadPool(
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: true
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      useDynamicWorker: true
+    })
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify INTERLEAVED_WEIGHTED_ROUND_ROBIN strategy default tasks statistics requirements', async () => {
     const workerChoiceStrategy =
       WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN
     let pool = new FixedThreadPool(
@@ -1184,7 +1756,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -1206,7 +1782,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -1248,7 +1828,21 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
     }
     expect(
@@ -1259,12 +1853,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentRoundId
+      ).roundId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1316,7 +1910,21 @@ describe('Selection strategies test suite', () => {
           median: 0,
           history: expect.any(CircularArray)
         },
-        elu: undefined
+        elu: {
+          idle: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          active: {
+            aggregate: 0,
+            average: 0,
+            median: 0,
+            history: expect.any(CircularArray)
+          },
+          utilization: 0
+        }
       })
     }
     expect(
@@ -1327,12 +1935,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentRoundId
+      ).roundId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1357,12 +1965,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentRoundId
+      ).roundId
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeId
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1378,12 +1986,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentRoundId
+      ).roundId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1408,12 +2016,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentRoundId
+      ).roundId
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeId
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1429,7 +2037,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(