+ public abstract reset (): boolean
+
+ /** @inheritDoc */
+ public abstract update (workerNodeKey: number): boolean
+
+ /** @inheritDoc */
+ public abstract choose (): number | undefined
+
+ /** @inheritDoc */
+ public abstract remove (workerNodeKey: number): boolean
+
+ /** @inheritDoc */
+ public setOptions (opts: WorkerChoiceStrategyOptions): void {
+ this.opts = { ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS, ...opts }
+ this.setTaskStatisticsRequirements(this.opts)
+ }
+
+ /**
+ * Whether the worker node is ready or not.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @returns Whether the worker node is ready or not.
+ */
+ private isWorkerNodeReady (workerNodeKey: number): boolean {
+ return this.pool.workerNodes[workerNodeKey].info.ready
+ }
+
+ /**
+ * Whether the worker node has back pressure or not (i.e. its tasks queue is full).
+ *
+ * @param workerNodeKey - The worker node key.
+ * @returns `true` if the worker node has back pressure, `false` otherwise.
+ */
+ private hasWorkerNodeBackPressure (workerNodeKey: number): boolean {
+ return this.pool.hasWorkerNodeBackPressure(workerNodeKey)
+ }
+
+ /**
+ * Whether the worker node is eligible or not.
+ * A worker node is eligible if it is ready and does not have back pressure.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @returns `true` if the worker node is eligible, `false` otherwise.
+ * @see {@link isWorkerNodeReady}
+ * @see {@link hasWorkerNodeBackPressure}
+ */
+ protected isWorkerNodeEligible (workerNodeKey: number): boolean {
+ return (
+ this.isWorkerNodeReady(workerNodeKey) &&
+ !this.hasWorkerNodeBackPressure(workerNodeKey)
+ )
+ }
+
+ /**
+ * Gets the worker task runtime.
+ * If the task statistics require the average runtime, the average runtime is returned.
+ * If the task statistics require the median runtime , the median runtime is returned.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @returns The worker task runtime.
+ */
+ protected getWorkerTaskRunTime (workerNodeKey: number): number {
+ return this.taskStatisticsRequirements.runTime.median
+ ? this.pool.workerNodes[workerNodeKey].usage.runTime?.median ?? 0
+ : this.pool.workerNodes[workerNodeKey].usage.runTime?.average ?? 0
+ }
+
+ /**
+ * Gets the worker task wait time.
+ * If the task statistics require the average wait time, the average wait time is returned.
+ * If the task statistics require the median wait time, the median wait time is returned.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @returns The worker task wait time.
+ */
+ protected getWorkerTaskWaitTime (workerNodeKey: number): number {
+ return this.taskStatisticsRequirements.waitTime.median
+ ? this.pool.workerNodes[workerNodeKey].usage.waitTime?.median ?? 0
+ : this.pool.workerNodes[workerNodeKey].usage.waitTime?.average ?? 0
+ }
+
+ /**
+ * Gets the worker task ELU.
+ * If the task statistics require the average ELU, the average ELU is returned.
+ * If the task statistics require the median ELU, the median ELU is returned.
+ *
+ * @param workerNodeKey - The worker node key.
+ * @returns The worker task ELU.
+ */
+ protected getWorkerTaskElu (workerNodeKey: number): number {
+ return this.taskStatisticsRequirements.elu.median
+ ? this.pool.workerNodes[workerNodeKey].usage.elu.active?.median ?? 0
+ : this.pool.workerNodes[workerNodeKey].usage.elu.active?.average ?? 0
+ }
+
+ /**
+ * Check the next worker node eligibility.
+ *
+ * @param chosenNextWorkerNodeKey - The chosen worker node key.
+ */
+ protected checkNextWorkerNodeEligibility (
+ chosenNextWorkerNodeKey: number | undefined
+ ): void {
+ if (!this.isWorkerNodeEligible(this.nextWorkerNodeKey as number)) {
+ this.nextWorkerNodeKey = undefined
+ this.previousWorkerNodeKey =
+ chosenNextWorkerNodeKey ?? this.previousWorkerNodeKey
+ }
+ }
+
+ protected computeDefaultWorkerWeight (): number {
+ let cpusCycleTimeWeight = 0
+ for (const cpu of cpus()) {
+ // CPU estimated cycle time
+ const numberOfDigits = cpu.speed.toString().length - 1
+ const cpuCycleTime = 1 / (cpu.speed / Math.pow(10, numberOfDigits))
+ cpusCycleTimeWeight += cpuCycleTime * Math.pow(10, numberOfDigits)
+ }
+ return Math.round(cpusCycleTimeWeight / cpus().length)
+ }