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 dbe286b40e5a46f7b262a700f130f4aad1bf82c4..1f99e086fc05d16eb064433f8584013fd44a30d7 100644 (file)
--- a/tests/pools/selection-strategies/selection-strategies.test.js
+++ b/tests/pools/selection-strategies/selection-strategies.test.js
@@ -1,9 +1,10 @@
 const { expect } = require('expect')
 const {
-  WorkerChoiceStrategies,
+  DynamicClusterPool,
   DynamicThreadPool,
+  FixedClusterPool,
   FixedThreadPool,
-  FixedClusterPool
+  WorkerChoiceStrategies
 } = require('../../../lib')
 const { CircularArray } = require('../../../lib/circular-array')
 
@@ -65,6 +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()
     }
   })
@@ -75,13 +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
@@ -98,8 +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
@@ -110,12 +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,
@@ -135,7 +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(
@@ -157,7 +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()
@@ -177,33 +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()
   })
@@ -223,33 +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()
   })
@@ -287,16 +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(
@@ -305,22 +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,
@@ -340,7 +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(
@@ -362,7 +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()
@@ -382,27 +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()
@@ -423,34 +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,
@@ -470,7 +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(
@@ -492,7 +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()
@@ -512,35 +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()
@@ -561,39 +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,
@@ -613,7 +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(
@@ -635,7 +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()
@@ -655,45 +914,50 @@ describe('Selection strategies test suite', () => {
     }
     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
-        })
-      } else {
-        expect(workerNode.workerUsage).toStrictEqual({
-          ...expectedWorkerUsage,
-          elu: {
-            active: expect.any(Number),
-            idle: 0,
-            utilization: 1
-          }
+          history: new CircularArray()
+        },
+        elu: expect.objectContaining({
+          idle: expect.objectContaining({
+            history: expect.any(CircularArray)
+          }),
+          active: expect.objectContaining({
+            history: expect.any(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
       )
+      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()
@@ -714,51 +978,82 @@ describe('Selection strategies test suite', () => {
     }
     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
-        })
-      } else {
-        expect(workerNode.workerUsage).toStrictEqual({
-          ...expectedWorkerUsage,
-          elu: {
-            active: expect.any(Number),
-            idle: 0,
-            utilization: 1
-          }
+          history: new CircularArray()
+        },
+        elu: expect.objectContaining({
+          idle: expect.objectContaining({
+            history: expect.any(CircularArray)
+          }),
+          active: expect.objectContaining({
+            history: expect.any(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
       )
+      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,
@@ -778,7 +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(
@@ -800,7 +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()
@@ -820,29 +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(
@@ -868,29 +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(
@@ -921,29 +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(
@@ -981,12 +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()
@@ -1016,19 +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,
@@ -1048,7 +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(
@@ -1070,7 +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()
@@ -1090,33 +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(
@@ -1147,33 +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(
@@ -1209,33 +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(
@@ -1260,7 +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(
@@ -1276,7 +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(
@@ -1285,7 +1758,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).workerVirtualTaskRunTime
     ).toBe(0)
     await pool.destroy()
@@ -1297,7 +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(
@@ -1313,7 +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(
@@ -1322,14 +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(
@@ -1341,8 +1851,8 @@ describe('Selection strategies test suite', () => {
       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
       runTime: {
-        aggregate: false,
-        average: false,
+        aggregate: true,
+        average: true,
         median: false
       },
       waitTime: {
@@ -1350,7 +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(
@@ -1363,8 +1877,8 @@ describe('Selection strategies test suite', () => {
       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
       runTime: {
-        aggregate: false,
-        average: false,
+        aggregate: true,
+        average: true,
         median: false
       },
       waitTime: {
@@ -1372,7 +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()
@@ -1395,27 +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(
@@ -1425,13 +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
@@ -1463,27 +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(
@@ -1493,13 +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
@@ -1523,12 +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(
@@ -1543,13 +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(
@@ -1558,7 +2130,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundWeights
     ).toStrictEqual([
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1574,12 +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(
@@ -1595,7 +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(
@@ -1604,7 +2201,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundWeights
     ).toStrictEqual([
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(