fix: test for worker file existence

[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 da261e89f930b94e52b872cff3c1c2b4796d8f26..6671b57781b1f51c15bdf0717f3c96cafcf0ca76 100644 (file)
--- a/tests/pools/selection-strategies/selection-strategies.test.js
+++ b/tests/pools/selection-strategies/selection-strategies.test.js
@@ -1,9 +1,9 @@
 const { expect } = require('expect')
 const {
-  WorkerChoiceStrategies,
   DynamicThreadPool,
+  FixedClusterPool,
   FixedThreadPool,
-  FixedClusterPool
+  WorkerChoiceStrategies
 } = require('../../../lib')
 const { CircularArray } = require('../../../lib/circular-array')
 
@@ -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'
@@ -78,7 +79,7 @@ describe('Selection strategies test suite', () => {
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
-          ).nextWorkerNodeId
+          ).nextWorkerNodeKey
         ).toBe(0)
       } else if (workerChoiceStrategy === WorkerChoiceStrategies.FAIR_SHARE) {
         expect(
@@ -97,7 +98,7 @@ describe('Selection strategies test suite', () => {
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
-          ).currentWorkerNodeId
+          ).nextWorkerNodeKey
         ).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,
@@ -122,14 +147,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: false,
-      avgRunTime: false,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -139,14 +173,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: false,
-      avgRunTime: false,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -166,24 +209,34 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: maxMultiplier,
-        running: 0,
-        runTime: 0,
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: 0,
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toStrictEqual({
+        tasks: {
+          executed: maxMultiplier,
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         WorkerChoiceStrategies.ROUND_ROBIN
-      ).nextWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -204,24 +257,34 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: maxMultiplier,
-        running: 0,
-        runTime: 0,
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: 0,
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toStrictEqual({
+        tasks: {
+          executed: maxMultiplier,
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         WorkerChoiceStrategies.ROUND_ROBIN
-      ).nextWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -263,13 +326,13 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).nextWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBeDefined()
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).nextWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -281,19 +344,43 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).nextWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBeDefined()
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).nextWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
     // We need to clean up the resources after our test
     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,
@@ -301,14 +388,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: false,
-      avgRunTime: false,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -318,14 +414,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: false,
-      avgRunTime: false,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -345,19 +450,33 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: maxMultiplier,
-        running: 0,
-        runTime: 0,
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: 0,
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toStrictEqual({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
     }
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -378,25 +497,63 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: maxMultiplier,
-        running: 0,
-        runTime: 0,
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: 0,
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toStrictEqual({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
     }
     // 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,
@@ -404,14 +561,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: true,
-      avgRunTime: false,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: true,
+        average: false,
+        median: false
+      },
+      waitTime: {
+        aggregate: true,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -421,14 +587,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: true,
-      avgRunTime: false,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: true,
+        average: false,
+        median: false
+      },
+      waitTime: {
+        aggregate: true,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -448,22 +623,43 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: expect.any(Number),
-        running: 0,
-        runTime: expect.any(Number),
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: 0,
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toMatchObject({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
-      expect(workerNode.tasksUsage.ran).toBeGreaterThan(0)
-      expect(workerNode.tasksUsage.ran).toBeLessThanOrEqual(max * maxMultiplier)
-      expect(workerNode.tasksUsage.runTime).toBeGreaterThan(0)
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      if (workerNode.usage.runTime.aggregate == null) {
+        expect(workerNode.usage.runTime.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.waitTime.aggregate == null) {
+        expect(workerNode.usage.waitTime.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.waitTime.aggregate).toBeGreaterThan(0)
+      }
     }
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -484,28 +680,258 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: expect.any(Number),
-        running: 0,
-        runTime: expect.any(Number),
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: 0,
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toMatchObject({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
-      expect(workerNode.tasksUsage.ran).toBeGreaterThan(0)
-      expect(workerNode.tasksUsage.ran).toBeLessThanOrEqual(max * maxMultiplier)
-      expect(workerNode.tasksUsage.runTime).toBeGreaterThan(0)
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      if (workerNode.usage.runTime.aggregate == null) {
+        expect(workerNode.usage.runTime.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.waitTime.aggregate == null) {
+        expect(workerNode.usage.waitTime.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.waitTime.aggregate).toBeGreaterThan(0)
+      }
     }
     // We need to clean up the resources after our test
     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.usage).toMatchObject({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: expect.objectContaining({
+            history: expect.any(CircularArray)
+          }),
+          active: expect.objectContaining({
+            history: expect.any(CircularArray)
+          })
+        }
+      })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      if (workerNode.usage.elu.utilization == null) {
+        expect(workerNode.usage.elu.utilization).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.utilization).toBeGreaterThanOrEqual(0)
+        expect(workerNode.usage.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.usage).toMatchObject({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: expect.objectContaining({
+            history: expect.any(CircularArray)
+          }),
+          active: expect.objectContaining({
+            history: expect.any(CircularArray)
+          })
+        }
+      })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      if (workerNode.usage.elu.utilization == null) {
+        expect(workerNode.usage.elu.utilization).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.utilization).toBeGreaterThanOrEqual(0)
+        expect(workerNode.usage.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,
@@ -513,14 +939,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: true,
-      avgRunTime: true,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: true,
+        average: true,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: true,
+        average: true,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -530,14 +965,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: true,
-      avgRunTime: true,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: true,
+        average: true,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: true,
+        average: true,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -557,21 +1001,49 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: maxMultiplier,
-        running: 0,
-        runTime: expect.any(Number),
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: expect.any(Number),
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toMatchObject({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: expect.objectContaining({
+          history: expect.any(CircularArray)
+        }),
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: expect.objectContaining({
+            history: expect.any(CircularArray)
+          }),
+          active: expect.objectContaining({
+            history: expect.any(CircularArray)
+          })
+        }
       })
-      expect(workerNode.tasksUsage.runTime).toBeGreaterThan(0)
-      expect(workerNode.tasksUsage.avgRunTime).toBeGreaterThan(0)
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      if (workerNode.usage.runTime.aggregate == null) {
+        expect(workerNode.usage.runTime.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.runTime.average == null) {
+        expect(workerNode.usage.runTime.average).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.average).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.utilization == null) {
+        expect(workerNode.usage.elu.utilization).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.utilization).toBeGreaterThanOrEqual(0)
+        expect(workerNode.usage.elu.utilization).toBeLessThanOrEqual(1)
+      }
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -597,21 +1069,49 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: maxMultiplier,
-        running: 0,
-        runTime: expect.any(Number),
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: expect.any(Number),
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toMatchObject({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: expect.objectContaining({
+          history: expect.any(CircularArray)
+        }),
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: expect.objectContaining({
+            history: expect.any(CircularArray)
+          }),
+          active: expect.objectContaining({
+            history: expect.any(CircularArray)
+          })
+        }
       })
-      expect(workerNode.tasksUsage.runTime).toBeGreaterThan(0)
-      expect(workerNode.tasksUsage.avgRunTime).toBeGreaterThan(0)
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      if (workerNode.usage.runTime.aggregate == null) {
+        expect(workerNode.usage.runTime.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.runTime.average == null) {
+        expect(workerNode.usage.runTime.average).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.average).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.utilization == null) {
+        expect(workerNode.usage.elu.utilization).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.utilization).toBeGreaterThanOrEqual(0)
+        expect(workerNode.usage.elu.utilization).toBeLessThanOrEqual(1)
+      }
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -630,7 +1130,7 @@ describe('Selection strategies test suite', () => {
       {
         workerChoiceStrategy: WorkerChoiceStrategies.FAIR_SHARE,
         workerChoiceStrategyOptions: {
-          medRunTime: true
+          runTime: { median: true }
         }
       }
     )
@@ -642,21 +1142,49 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: maxMultiplier,
-        running: 0,
-        runTime: expect.any(Number),
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: 0,
-        medRunTime: expect.any(Number),
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toMatchObject({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: expect.objectContaining({
+          history: expect.any(CircularArray)
+        }),
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: expect.objectContaining({
+            history: expect.any(CircularArray)
+          }),
+          active: expect.objectContaining({
+            history: expect.any(CircularArray)
+          })
+        }
       })
-      expect(workerNode.tasksUsage.runTime).toBeGreaterThan(0)
-      expect(workerNode.tasksUsage.medRunTime).toBeGreaterThan(0)
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      if (workerNode.usage.runTime.aggregate == null) {
+        expect(workerNode.usage.runTime.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.runTime.median == null) {
+        expect(workerNode.usage.runTime.median).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.median).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.utilization == null) {
+        expect(workerNode.usage.elu.utilization).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.utilization).toBeGreaterThanOrEqual(0)
+        expect(workerNode.usage.elu.utilization).toBeLessThanOrEqual(1)
+      }
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -741,7 +1269,31 @@ 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,
@@ -749,14 +1301,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: true,
-      avgRunTime: true,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: true,
+        average: true,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -766,14 +1327,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: true,
-      avgRunTime: true,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: true,
+        average: true,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -793,23 +1363,43 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: expect.any(Number),
-        running: 0,
-        runTime: expect.any(Number),
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: expect.any(Number),
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toStrictEqual({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: expect.objectContaining({
+          history: expect.any(CircularArray)
+        }),
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
-      expect(workerNode.tasksUsage.ran).toBeGreaterThanOrEqual(0)
-      expect(workerNode.tasksUsage.ran).toBeLessThanOrEqual(max * maxMultiplier)
-      expect(workerNode.tasksUsage.runTime).toBeGreaterThanOrEqual(0)
-      expect(workerNode.tasksUsage.avgRunTime).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      if (workerNode.usage.runTime.aggregate == null) {
+        expect(workerNode.usage.runTime.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.runTime.average == null) {
+        expect(workerNode.usage.runTime.average).toBeUndefined()
+      } else {
+        expect(workerNode.usage.runTime.average).toBeGreaterThan(0)
+      }
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -840,23 +1430,39 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: expect.any(Number),
-        running: 0,
-        runTime: expect.any(Number),
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: expect.any(Number),
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toStrictEqual({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          aggregate: expect.any(Number),
+          maximum: expect.any(Number),
+          minimum: expect.any(Number),
+          average: expect.any(Number),
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
-      expect(workerNode.tasksUsage.ran).toBeGreaterThan(0)
-      expect(workerNode.tasksUsage.ran).toBeLessThanOrEqual(max * maxMultiplier)
-      expect(workerNode.tasksUsage.runTime).toBeGreaterThan(0)
-      expect(workerNode.tasksUsage.avgRunTime).toBeGreaterThan(0)
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
+      expect(workerNode.usage.runTime.average).toBeGreaterThan(0)
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -880,7 +1486,7 @@ describe('Selection strategies test suite', () => {
       {
         workerChoiceStrategy: WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN,
         workerChoiceStrategyOptions: {
-          medRunTime: true
+          runTime: { median: true }
         }
       }
     )
@@ -892,23 +1498,39 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: expect.any(Number),
-        running: 0,
-        runTime: expect.any(Number),
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: 0,
-        medRunTime: expect.any(Number),
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toStrictEqual({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          aggregate: expect.any(Number),
+          maximum: expect.any(Number),
+          minimum: expect.any(Number),
+          median: expect.any(Number),
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
-      expect(workerNode.tasksUsage.ran).toBeGreaterThan(0)
-      expect(workerNode.tasksUsage.ran).toBeLessThanOrEqual(max * maxMultiplier)
-      expect(workerNode.tasksUsage.runTime).toBeGreaterThan(0)
-      expect(workerNode.tasksUsage.medRunTime).toBeGreaterThan(0)
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
+      expect(workerNode.usage.runTime.aggregate).toBeGreaterThan(0)
+      expect(workerNode.usage.runTime.median).toBeGreaterThan(0)
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -933,7 +1555,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -949,7 +1571,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -970,7 +1592,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -986,7 +1608,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1002,7 +1624,32 @@ 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(
@@ -1011,14 +1658,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: false,
-      avgRunTime: false,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -1028,14 +1684,23 @@ describe('Selection strategies test suite', () => {
       { workerChoiceStrategy }
     )
     expect(
-      pool.workerChoiceStrategyContext.getRequiredStatistics()
+      pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
-      runTime: false,
-      avgRunTime: false,
-      medRunTime: false,
-      waitTime: false,
-      avgWaitTime: false,
-      medWaitTime: false
+      runTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      waitTime: {
+        aggregate: false,
+        average: false,
+        median: false
+      },
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -1058,18 +1723,28 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: maxMultiplier,
-        running: 0,
-        runTime: 0,
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: 0,
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toStrictEqual({
+        tasks: {
+          executed: maxMultiplier,
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
     }
     expect(
@@ -1080,12 +1755,12 @@ 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
+      ).nextWorkerNodeKey
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1118,18 +1793,28 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.tasksUsage).toStrictEqual({
-        ran: maxMultiplier,
-        running: 0,
-        runTime: 0,
-        runTimeHistory: expect.any(CircularArray),
-        avgRunTime: 0,
-        medRunTime: 0,
-        waitTime: 0,
-        waitTimeHistory: expect.any(CircularArray),
-        avgWaitTime: 0,
-        medWaitTime: 0,
-        error: 0
+      expect(workerNode.usage).toStrictEqual({
+        tasks: {
+          executed: maxMultiplier,
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          failed: 0
+        },
+        runTime: {
+          history: expect.any(CircularArray)
+        },
+        waitTime: {
+          history: expect.any(CircularArray)
+        },
+        elu: {
+          idle: {
+            history: expect.any(CircularArray)
+          },
+          active: {
+            history: expect.any(CircularArray)
+          }
+        }
       })
     }
     expect(
@@ -1140,12 +1825,12 @@ 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
+      ).nextWorkerNodeKey
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1170,12 +1855,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentRoundId
+      ).roundId
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1191,12 +1876,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentRoundId
+      ).roundId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1221,12 +1906,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentRoundId
+      ).roundId
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1242,7 +1927,7 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(