test: improve WCS coverage

[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 8e226860c2e3a018cda341a26959deb11ae88ed5..1f99e086fc05d16eb064433f8584013fd44a30d7 100644 (file)
--- a/tests/pools/selection-strategies/selection-strategies.test.js
+++ b/tests/pools/selection-strategies/selection-strategies.test.js
@@ -1,12 +1,12 @@
 const { expect } = require('expect')
 const {
-  WorkerChoiceStrategies,
+  DynamicClusterPool,
   DynamicThreadPool,
+  FixedClusterPool,
   FixedThreadPool,
-  FixedClusterPool
+  WorkerChoiceStrategies
 } = require('../../../lib')
 const { CircularArray } = require('../../../lib/circular-array')
-const TestUtils = require('../../test-utils')
 
 describe('Selection strategies test suite', () => {
   const min = 0
@@ -66,6 +66,43 @@ describe('Selection strategies test suite', () => {
       expect(pool.workerChoiceStrategyContext.workerChoiceStrategy).toBe(
         workerChoiceStrategy
       )
+      expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
+        retries: 6,
+        runTime: { median: false },
+        waitTime: { median: false },
+        elu: { median: false }
+      })
+      expect(pool.workerChoiceStrategyContext.opts).toStrictEqual({
+        retries: 6,
+        runTime: { median: false },
+        waitTime: { median: false },
+        elu: { median: false }
+      })
+      await pool.destroy()
+    }
+    for (const workerChoiceStrategy of Object.values(WorkerChoiceStrategies)) {
+      const pool = new DynamicClusterPool(
+        min,
+        max,
+        './tests/worker-files/cluster/testWorker.js'
+      )
+      pool.setWorkerChoiceStrategy(workerChoiceStrategy, { retries: 3 })
+      expect(pool.opts.workerChoiceStrategy).toBe(workerChoiceStrategy)
+      expect(pool.workerChoiceStrategyContext.workerChoiceStrategy).toBe(
+        workerChoiceStrategy
+      )
+      expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
+        retries: 3,
+        runTime: { median: false },
+        waitTime: { median: false },
+        elu: { median: false }
+      })
+      expect(pool.workerChoiceStrategyContext.opts).toStrictEqual({
+        retries: 3,
+        runTime: { median: false },
+        waitTime: { median: false },
+        elu: { median: false }
+      })
       await pool.destroy()
     }
   })
@@ -76,13 +113,17 @@ describe('Selection strategies test suite', () => {
       './tests/worker-files/thread/testWorker.js'
     )
     for (const workerChoiceStrategy of Object.values(WorkerChoiceStrategies)) {
-      if (workerChoiceStrategy === WorkerChoiceStrategies.ROUND_ROBIN) {
-        expect(
-          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-            workerChoiceStrategy
-          ).nextWorkerNodeId
-        ).toBe(0)
-      } else if (workerChoiceStrategy === WorkerChoiceStrategies.FAIR_SHARE) {
+      expect(
+        pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+          workerChoiceStrategy
+        ).nextWorkerNodeKey
+      ).toBe(0)
+      expect(
+        pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+          workerChoiceStrategy
+        ).previousWorkerNodeKey
+      ).toBe(0)
+      if (workerChoiceStrategy === WorkerChoiceStrategies.FAIR_SHARE) {
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
@@ -99,8 +140,17 @@ describe('Selection strategies test suite', () => {
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
-          ).currentWorkerNodeId
+          ).defaultWorkerWeight
+        ).toBeGreaterThan(0)
+        expect(
+          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+            workerChoiceStrategy
+          ).workerVirtualTaskRunTime
         ).toBe(0)
+      } else if (
+        workerChoiceStrategy ===
+        WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN
+      ) {
         expect(
           pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
             workerChoiceStrategy
@@ -111,12 +161,57 @@ describe('Selection strategies test suite', () => {
             workerChoiceStrategy
           ).workerVirtualTaskRunTime
         ).toBe(0)
+        expect(
+          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+            workerChoiceStrategy
+          ).roundId
+        ).toBe(0)
+        expect(
+          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+            workerChoiceStrategy
+          ).workerNodeId
+        ).toBe(0)
+        expect(
+          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+            workerChoiceStrategy
+          ).roundWeights
+        ).toStrictEqual([
+          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+            workerChoiceStrategy
+          ).defaultWorkerWeight
+        ])
       }
     }
     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({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: 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,
@@ -136,7 +231,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -158,7 +257,11 @@ 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()
@@ -178,33 +281,41 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: maxMultiplier,
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new CircularArray()
+          }
+        }
       })
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         WorkerChoiceStrategies.ROUND_ROBIN
-      ).nextWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        WorkerChoiceStrategies.ROUND_ROBIN
+      ).previousWorkerNodeKey
+    ).toBe(pool.workerNodes.length - 1)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -224,33 +335,45 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new CircularArray()
+          }
+        }
       })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         WorkerChoiceStrategies.ROUND_ROBIN
-      ).nextWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        WorkerChoiceStrategies.ROUND_ROBIN
+      ).previousWorkerNodeKey
+    ).toBe(pool.workerNodes.length - 1)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -288,16 +411,16 @@ describe('Selection strategies test suite', () => {
       './tests/worker-files/thread/testWorker.js',
       { workerChoiceStrategy: WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN }
     )
+    pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).nextWorkerNodeId
-    ).toBeDefined()
-    pool.setWorkerChoiceStrategy(workerChoiceStrategy)
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).nextWorkerNodeId
+      ).previousWorkerNodeKey
     ).toBe(0)
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -306,22 +429,48 @@ describe('Selection strategies test suite', () => {
       './tests/worker-files/thread/testWorker.js',
       { workerChoiceStrategy: WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN }
     )
+    pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).nextWorkerNodeId
-    ).toBeDefined()
-    pool.setWorkerChoiceStrategy(workerChoiceStrategy)
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).nextWorkerNodeId
+      ).previousWorkerNodeKey
     ).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({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    // 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,
@@ -341,7 +490,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -363,7 +516,11 @@ 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()
@@ -383,27 +540,34 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new 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()
@@ -424,34 +588,66 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-
-        elu: undefined
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new 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({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    // 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,
@@ -471,7 +667,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -493,7 +693,11 @@ 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()
@@ -513,35 +717,44 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: expect.any(Number),
-          average: 0,
-          median: 0,
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
-        waitTime: {
-          aggregate: expect.any(Number),
-          average: 0,
-          median: 0,
+        }),
+        waitTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
-        elu: undefined
+        }),
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new CircularArray()
+          }
+        }
       })
-      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
-      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
-      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThanOrEqual(0)
-      expect(workerNode.workerUsage.waitTime.aggregate).toBeGreaterThanOrEqual(
-        0
-      )
+      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()
@@ -562,39 +775,76 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: expect.any(Number),
-          average: 0,
-          median: 0,
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
-        waitTime: {
-          aggregate: expect.any(Number),
-          average: 0,
-          median: 0,
+        }),
+        waitTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
-        elu: undefined
+        }),
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new CircularArray()
+          }
+        }
       })
-      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
-      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.waitTime.aggregate).toBeGreaterThan(0)
+      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 LEAST_ELU 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({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    // 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,
@@ -614,7 +864,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: true
+      elu: {
+        aggregate: true,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -636,7 +890,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: true
+      elu: {
+        aggregate: true,
+        average: false,
+        median: false
+      }
     })
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -649,57 +907,153 @@ describe('Selection strategies test suite', () => {
       { 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++) {
-      await pool.execute()
-      if (i !== max * maxMultiplier - 1) await TestUtils.sleep(500)
+      promises.add(pool.execute())
     }
+    await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      const expectedWorkerUsage = {
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
-        }
-      }
-      if (workerNode.workerUsage.elu === undefined) {
-        expect(workerNode.workerUsage).toStrictEqual({
-          ...expectedWorkerUsage,
-          elu: undefined
+          history: new CircularArray()
+        },
+        elu: expect.objectContaining({
+          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.active.aggregate == null) {
+        expect(workerNode.usage.elu.active.aggregate).toBeUndefined()
       } else {
-        expect(workerNode.workerUsage).toStrictEqual({
-          ...expectedWorkerUsage,
-          elu: {
-            active: expect.any(Number),
-            idle: 0,
-            utilization: 1
-          }
-        })
+        expect(workerNode.usage.elu.active.aggregate).toBeGreaterThan(0)
       }
-      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
-      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+      if (workerNode.usage.elu.idle.aggregate == null) {
+        expect(workerNode.usage.elu.idle.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.idle.aggregate).toBeGreaterThanOrEqual(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)
+      }
+    }
+    // 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).toStrictEqual({
+        tasks: {
+          executed: expect.any(Number),
+          executing: 0,
+          queued: 0,
+          maxQueued: 0,
+          stolen: 0,
+          failed: 0
+        },
+        runTime: {
+          history: new CircularArray()
+        },
+        waitTime: {
+          history: new CircularArray()
+        },
+        elu: expect.objectContaining({
+          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.active.aggregate == null) {
+        expect(workerNode.usage.elu.active.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.active.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.idle.aggregate == null) {
+        expect(workerNode.usage.elu.idle.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.idle.aggregate).toBeGreaterThanOrEqual(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)
+      }
     }
     // 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 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({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    // 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,
@@ -719,7 +1073,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: true,
+        average: true,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -741,7 +1099,11 @@ 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()
@@ -761,29 +1123,60 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: expect.any(Number),
-          average: expect.any(Number),
-          median: 0,
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: expect.objectContaining({
+          idle: expect.objectContaining({
+            history: expect.any(CircularArray)
+          }),
+          active: expect.objectContaining({
+            history: expect.any(CircularArray)
+          })
+        })
       })
-      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.runTime.average).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.active.aggregate == null) {
+        expect(workerNode.usage.elu.active.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.active.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.idle.aggregate == null) {
+        expect(workerNode.usage.elu.idle.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.idle.aggregate).toBeGreaterThanOrEqual(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(
@@ -809,29 +1202,60 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: expect.any(Number),
-          average: expect.any(Number),
-          median: 0,
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: expect.objectContaining({
+          idle: expect.objectContaining({
+            history: expect.any(CircularArray)
+          }),
+          active: expect.objectContaining({
+            history: expect.any(CircularArray)
+          })
+        })
       })
-      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.runTime.average).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.active.aggregate == null) {
+        expect(workerNode.usage.elu.active.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.active.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.idle.aggregate == null) {
+        expect(workerNode.usage.elu.idle.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.idle.aggregate).toBeGreaterThanOrEqual(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(
@@ -862,29 +1286,60 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: expect.any(Number),
-          average: 0,
-          median: expect.any(Number),
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: expect.objectContaining({
+          idle: expect.objectContaining({
+            history: expect.any(CircularArray)
+          }),
+          active: expect.objectContaining({
+            history: expect.any(CircularArray)
+          })
+        })
       })
-      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.runTime.median).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.active.aggregate == null) {
+        expect(workerNode.usage.elu.active.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.active.aggregate).toBeGreaterThan(0)
+      }
+      if (workerNode.usage.elu.idle.aggregate == null) {
+        expect(workerNode.usage.elu.idle.aggregate).toBeUndefined()
+      } else {
+        expect(workerNode.usage.elu.idle.aggregate).toBeGreaterThanOrEqual(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(
@@ -922,12 +1377,12 @@ describe('Selection strategies test suite', () => {
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).workersVirtualTaskEndTimestamp
     ).toBeInstanceOf(Array)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).workersVirtualTaskEndTimestamp.length
     ).toBe(0)
     await pool.destroy()
@@ -957,19 +1412,45 @@ describe('Selection strategies test suite', () => {
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).workersVirtualTaskEndTimestamp
     ).toBeInstanceOf(Array)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).workersVirtualTaskEndTimestamp.length
     ).toBe(0)
     // We need to clean up the resources after our test
     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({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: 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,
@@ -989,7 +1470,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -1011,7 +1496,11 @@ 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()
@@ -1031,33 +1520,44 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: expect.any(Number),
-          average: expect.any(Number),
-          median: 0,
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new CircularArray()
+          }
+        }
       })
-      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThanOrEqual(0)
-      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
-      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThanOrEqual(0)
-      expect(workerNode.workerUsage.runTime.average).toBeGreaterThanOrEqual(0)
+      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(
@@ -1088,33 +1588,44 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: expect.any(Number),
-          average: expect.any(Number),
-          median: 0,
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new CircularArray()
+          }
+        }
       })
-      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
-      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.runTime.average).toBeGreaterThan(0)
+      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(
@@ -1150,33 +1661,44 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: expect.any(Number),
-          average: 0,
-          median: expect.any(Number),
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new CircularArray()
+          }
+        }
       })
-      expect(workerNode.workerUsage.tasks.executed).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
         max * maxMultiplier
       )
-      expect(workerNode.workerUsage.runTime.aggregate).toBeGreaterThan(0)
-      expect(workerNode.workerUsage.runTime.median).toBeGreaterThan(0)
+      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)
+      }
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1201,7 +1723,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
+    ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).previousWorkerNodeKey
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1217,7 +1744,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1226,7 +1758,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).workerVirtualTaskRunTime
     ).toBe(0)
     await pool.destroy()
@@ -1238,7 +1770,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
+    ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).previousWorkerNodeKey
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1254,7 +1791,12 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1263,14 +1805,41 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).workerVirtualTaskRunTime
     ).toBe(0)
     // We need to clean up the resources after our test
     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({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: true
+    })
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    expect(pool.workerChoiceStrategyContext.getStrategyPolicy()).toStrictEqual({
+      dynamicWorkerUsage: false,
+      dynamicWorkerReady: 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(
@@ -1282,8 +1851,8 @@ describe('Selection strategies test suite', () => {
       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
       runTime: {
-        aggregate: false,
-        average: false,
+        aggregate: true,
+        average: true,
         median: false
       },
       waitTime: {
@@ -1291,7 +1860,11 @@ describe('Selection strategies test suite', () => {
         average: false,
         median: false
       },
-      elu: false
+      elu: {
+        aggregate: false,
+        average: false,
+        median: false
+      }
     })
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -1304,8 +1877,8 @@ describe('Selection strategies test suite', () => {
       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
       runTime: {
-        aggregate: false,
-        average: false,
+        aggregate: true,
+        average: true,
         median: false
       },
       waitTime: {
@@ -1313,7 +1886,11 @@ 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()
@@ -1336,27 +1913,34 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new CircularArray()
+          }
+        }
       })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1366,13 +1950,23 @@ 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
+      ).workerNodeId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1404,27 +1998,34 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.workerUsage).toStrictEqual({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
+          maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          aggregate: 0,
-          average: 0,
-          median: 0,
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: undefined
+        elu: {
+          idle: {
+            history: new CircularArray()
+          },
+          active: {
+            history: new CircularArray()
+          }
+        }
       })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1434,13 +2035,23 @@ 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
+      ).workerNodeId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toEqual(expect.any(Number))
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1464,12 +2075,22 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentRoundId
+      ).roundId
+    ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).workerNodeId
+    ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).nextWorkerNodeKey
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).previousWorkerNodeKey
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1484,13 +2105,23 @@ describe('Selection strategies test suite', () => {
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
-      ).currentRoundId
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).roundId
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).workerNodeId
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1499,7 +2130,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundWeights
     ).toStrictEqual([
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1515,12 +2146,22 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentRoundId
+      ).roundId
+    ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).workerNodeId
+    ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).nextWorkerNodeKey
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).previousWorkerNodeKey
     ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1536,7 +2177,22 @@ describe('Selection strategies test suite', () => {
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
-      ).currentWorkerNodeId
+      ).roundId
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).workerNodeId
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeKey
+    ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
     ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1545,7 +2201,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundWeights
     ).toStrictEqual([
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(