refactor: untangle worker eligibility from previous worker node

[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 0e47e18efade43e35b2894ba6824d666ddb13daa..055a2dbb64e6257bef21221f709c2e0756b89d84 100644 (file)
--- a/tests/pools/selection-strategies/selection-strategies.test.js
+++ b/tests/pools/selection-strategies/selection-strategies.test.js
@@ -1,5 +1,6 @@
 const { expect } = require('expect')
 const {
+  DynamicClusterPool,
   DynamicThreadPool,
   FixedClusterPool,
   FixedThreadPool,
@@ -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
-          ).nextWorkerNodeKey
-        ).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
-          ).nextWorkerNodeKey
+          ).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
@@ -110,6 +161,25 @@ 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()
@@ -198,10 +268,11 @@ describe('Selection strategies test suite', () => {
   })
 
   it('Verify ROUND_ROBIN strategy can be run in a fixed pool', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
     const pool = new FixedThreadPool(
       max,
       './tests/worker-files/thread/testWorker.js',
-      { workerChoiceStrategy: WorkerChoiceStrategies.ROUND_ROBIN }
+      { workerChoiceStrategy }
     )
     // TODO: Create a better test to cover `RoundRobinWorkerChoiceStrategy#choose`
     const promises = new Set()
@@ -217,39 +288,46 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        WorkerChoiceStrategies.ROUND_ROBIN
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(pool.workerNodes.length - 1)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
   it('Verify ROUND_ROBIN strategy can be run in a dynamic pool', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
     const pool = new DynamicThreadPool(
       min,
       max,
       './tests/worker-files/thread/testWorker.js',
-      { workerChoiceStrategy: WorkerChoiceStrategies.ROUND_ROBIN }
+      { workerChoiceStrategy }
     )
     // TODO: Create a better test to cover `RoundRobinWorkerChoiceStrategy#choose`
     const promises = new Set()
@@ -265,20 +343,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -289,9 +368,14 @@ describe('Selection strategies test suite', () => {
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        WorkerChoiceStrategies.ROUND_ROBIN
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(pool.workerNodes.length - 1)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -331,15 +415,25 @@ describe('Selection strategies test suite', () => {
     )
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     await pool.destroy()
     pool = new DynamicThreadPool(
       min,
@@ -349,15 +443,25 @@ describe('Selection strategies test suite', () => {
     )
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -464,20 +568,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -511,20 +616,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -633,26 +739,27 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
-        waitTime: {
+        }),
+        waitTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -690,26 +797,27 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
-        waitTime: {
+        }),
+        waitTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -828,33 +936,44 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: {
+        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 {
@@ -881,33 +1000,44 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: {
+        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 {
@@ -1015,28 +1145,29 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: expect.objectContaining({
           history: expect.any(CircularArray)
         }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: {
+        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(
@@ -1052,6 +1183,16 @@ describe('Selection strategies test suite', () => {
       } 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 {
@@ -1083,28 +1224,29 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: expect.objectContaining({
           history: expect.any(CircularArray)
         }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: {
+        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(
@@ -1120,6 +1262,16 @@ describe('Selection strategies test suite', () => {
       } 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 {
@@ -1156,28 +1308,29 @@ describe('Selection strategies test suite', () => {
     }
     await Promise.all(promises)
     for (const workerNode of pool.workerNodes) {
-      expect(workerNode.usage).toMatchObject({
+      expect(workerNode.usage).toStrictEqual({
         tasks: {
           executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: expect.objectContaining({
           history: expect.any(CircularArray)
         }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
-        elu: {
+        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(
@@ -1193,6 +1346,16 @@ describe('Selection strategies test suite', () => {
       } 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 {
@@ -1236,12 +1399,12 @@ 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()
@@ -1271,12 +1434,12 @@ 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)
     // We need to clean up the resources after our test
@@ -1385,20 +1548,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: expect.objectContaining({
           history: expect.any(CircularArray)
         }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -1417,6 +1581,16 @@ describe('Selection strategies test suite', () => {
         expect(workerNode.usage.runTime.average).toBeGreaterThan(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(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1452,20 +1626,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: expect.objectContaining({
           history: expect.any(CircularArray)
         }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -1484,6 +1659,16 @@ describe('Selection strategies test suite', () => {
         expect(workerNode.usage.runTime.average).toBeGreaterThan(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(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1524,20 +1709,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
         runTime: expect.objectContaining({
           history: expect.any(CircularArray)
         }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -1556,6 +1742,16 @@ describe('Selection strategies test suite', () => {
         expect(workerNode.usage.runTime.median).toBeGreaterThan(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(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1581,6 +1777,11 @@ describe('Selection strategies test suite', () => {
         workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
@@ -1597,6 +1798,11 @@ describe('Selection strategies test suite', () => {
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1604,7 +1810,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).workerVirtualTaskRunTime
     ).toBe(0)
     await pool.destroy()
@@ -1618,6 +1824,11 @@ describe('Selection strategies test suite', () => {
         workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
@@ -1634,6 +1845,11 @@ describe('Selection strategies test suite', () => {
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBe(0)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBe(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1641,7 +1857,7 @@ 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
@@ -1687,8 +1903,8 @@ describe('Selection strategies test suite', () => {
       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
       runTime: {
-        aggregate: false,
-        average: false,
+        aggregate: true,
+        average: true,
         median: false
       },
       waitTime: {
@@ -1713,8 +1929,8 @@ describe('Selection strategies test suite', () => {
       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
     ).toStrictEqual({
       runTime: {
-        aggregate: false,
-        average: false,
+        aggregate: true,
+        average: true,
         median: false
       },
       waitTime: {
@@ -1751,27 +1967,32 @@ describe('Selection strategies test suite', () => {
     for (const workerNode of pool.workerNodes) {
       expect(workerNode.usage).toStrictEqual({
         tasks: {
-          executed: maxMultiplier,
+          executed: expect.any(Number),
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
+      expect(workerNode.usage.tasks.executed).toBeGreaterThanOrEqual(0)
+      expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(
+        max * maxMultiplier
+      )
     }
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1783,11 +2004,21 @@ describe('Selection strategies test suite', () => {
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).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
+    ).toEqual(expect.any(Number))
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1825,20 +2056,21 @@ describe('Selection strategies test suite', () => {
           executing: 0,
           queued: 0,
           maxQueued: 0,
+          stolen: 0,
           failed: 0
         },
-        runTime: {
+        runTime: expect.objectContaining({
           history: expect.any(CircularArray)
-        },
+        }),
         waitTime: {
-          history: expect.any(CircularArray)
+          history: new CircularArray()
         },
         elu: {
           idle: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           },
           active: {
-            history: expect.any(CircularArray)
+            history: new CircularArray()
           }
         }
       })
@@ -1857,11 +2089,21 @@ describe('Selection strategies test suite', () => {
         pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).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
+    ).toEqual(expect.any(Number))
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1887,11 +2129,21 @@ describe('Selection strategies test suite', () => {
         workerChoiceStrategy
       ).roundId
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).workerNodeId
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
@@ -1905,14 +2157,24 @@ describe('Selection strategies test suite', () => {
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).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(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1920,7 +2182,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundWeights
     ).toStrictEqual([
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
@@ -1938,11 +2200,21 @@ describe('Selection strategies test suite', () => {
         workerChoiceStrategy
       ).roundId
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).workerNodeId
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
       ).nextWorkerNodeKey
     ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).previousWorkerNodeKey
+    ).toBeDefined()
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
         workerChoiceStrategy
@@ -1954,11 +2226,26 @@ describe('Selection strategies test suite', () => {
       ).roundWeights
     ).toBeDefined()
     pool.setWorkerChoiceStrategy(workerChoiceStrategy)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).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(
         pool.workerChoiceStrategyContext.workerChoiceStrategy
@@ -1966,7 +2253,7 @@ describe('Selection strategies test suite', () => {
     ).toBeGreaterThan(0)
     expect(
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
-        workerChoiceStrategy
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
       ).roundWeights
     ).toStrictEqual([
       pool.workerChoiceStrategyContext.workerChoiceStrategies.get(