| 1 | import { cpus } from 'node:os' |
| 2 | import { |
| 3 | DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS, |
| 4 | DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS |
| 5 | } from '../../utils' |
| 6 | import type { IPool } from '../pool' |
| 7 | import type { IWorker } from '../worker' |
| 8 | import type { |
| 9 | IWorkerChoiceStrategy, |
| 10 | MeasurementStatisticsRequirements, |
| 11 | StrategyPolicy, |
| 12 | TaskStatisticsRequirements, |
| 13 | WorkerChoiceStrategyOptions |
| 14 | } from './selection-strategies-types' |
| 15 | |
| 16 | /** |
| 17 | * Worker choice strategy abstract base class. |
| 18 | * |
| 19 | * @typeParam Worker - Type of worker which manages the strategy. |
| 20 | * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data. |
| 21 | * @typeParam Response - Type of execution response. This can only be structured-cloneable data. |
| 22 | */ |
| 23 | export abstract class AbstractWorkerChoiceStrategy< |
| 24 | Worker extends IWorker, |
| 25 | Data = unknown, |
| 26 | Response = unknown |
| 27 | > implements IWorkerChoiceStrategy { |
| 28 | /** |
| 29 | * The next worker node key. |
| 30 | */ |
| 31 | protected nextWorkerNodeKey: number | undefined = 0 |
| 32 | |
| 33 | /** |
| 34 | * The previous worker node key. |
| 35 | */ |
| 36 | protected previousWorkerNodeKey: number = 0 |
| 37 | |
| 38 | /** @inheritDoc */ |
| 39 | public readonly strategyPolicy: StrategyPolicy = { |
| 40 | dynamicWorkerUsage: false, |
| 41 | dynamicWorkerReady: true |
| 42 | } |
| 43 | |
| 44 | /** @inheritDoc */ |
| 45 | public readonly taskStatisticsRequirements: TaskStatisticsRequirements = { |
| 46 | runTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS, |
| 47 | waitTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS, |
| 48 | elu: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS |
| 49 | } |
| 50 | |
| 51 | /** |
| 52 | * Constructs a worker choice strategy bound to the pool. |
| 53 | * |
| 54 | * @param pool - The pool instance. |
| 55 | * @param opts - The worker choice strategy options. |
| 56 | */ |
| 57 | public constructor ( |
| 58 | protected readonly pool: IPool<Worker, Data, Response>, |
| 59 | protected opts: WorkerChoiceStrategyOptions = DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS |
| 60 | ) { |
| 61 | this.opts = { ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS, ...opts } |
| 62 | this.choose = this.choose.bind(this) |
| 63 | } |
| 64 | |
| 65 | protected setTaskStatisticsRequirements ( |
| 66 | opts: WorkerChoiceStrategyOptions |
| 67 | ): void { |
| 68 | this.toggleMedianMeasurementStatisticsRequirements( |
| 69 | this.taskStatisticsRequirements.runTime, |
| 70 | opts.runTime?.median as boolean |
| 71 | ) |
| 72 | this.toggleMedianMeasurementStatisticsRequirements( |
| 73 | this.taskStatisticsRequirements.waitTime, |
| 74 | opts.waitTime?.median as boolean |
| 75 | ) |
| 76 | this.toggleMedianMeasurementStatisticsRequirements( |
| 77 | this.taskStatisticsRequirements.elu, |
| 78 | opts.elu?.median as boolean |
| 79 | ) |
| 80 | } |
| 81 | |
| 82 | private toggleMedianMeasurementStatisticsRequirements ( |
| 83 | measurementStatisticsRequirements: MeasurementStatisticsRequirements, |
| 84 | toggleMedian: boolean |
| 85 | ): void { |
| 86 | if (measurementStatisticsRequirements.average && toggleMedian) { |
| 87 | measurementStatisticsRequirements.average = false |
| 88 | measurementStatisticsRequirements.median = toggleMedian |
| 89 | } |
| 90 | if (measurementStatisticsRequirements.median && !toggleMedian) { |
| 91 | measurementStatisticsRequirements.average = true |
| 92 | measurementStatisticsRequirements.median = toggleMedian |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | protected resetWorkerNodeKeyProperties (): void { |
| 97 | this.nextWorkerNodeKey = 0 |
| 98 | this.previousWorkerNodeKey = 0 |
| 99 | } |
| 100 | |
| 101 | /** @inheritDoc */ |
| 102 | public abstract reset (): boolean |
| 103 | |
| 104 | /** @inheritDoc */ |
| 105 | public abstract update (workerNodeKey: number): boolean |
| 106 | |
| 107 | /** @inheritDoc */ |
| 108 | public abstract choose (): number | undefined |
| 109 | |
| 110 | /** @inheritDoc */ |
| 111 | public abstract remove (workerNodeKey: number): boolean |
| 112 | |
| 113 | /** @inheritDoc */ |
| 114 | public setOptions (opts: WorkerChoiceStrategyOptions): void { |
| 115 | this.opts = { ...DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS, ...opts } |
| 116 | this.setTaskStatisticsRequirements(this.opts) |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * Whether the worker node is ready or not. |
| 121 | * |
| 122 | * @param workerNodeKey - The worker node key. |
| 123 | * @returns Whether the worker node is ready or not. |
| 124 | */ |
| 125 | private isWorkerNodeReady (workerNodeKey: number): boolean { |
| 126 | return this.pool.workerNodes[workerNodeKey].info.ready |
| 127 | } |
| 128 | |
| 129 | /** |
| 130 | * Whether the worker node has back pressure or not (i.e. its tasks queue is full). |
| 131 | * |
| 132 | * @param workerNodeKey - The worker node key. |
| 133 | * @returns `true` if the worker node has back pressure, `false` otherwise. |
| 134 | */ |
| 135 | private hasWorkerNodeBackPressure (workerNodeKey: number): boolean { |
| 136 | return this.pool.hasWorkerNodeBackPressure(workerNodeKey) |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * Whether the worker node is eligible or not. |
| 141 | * A worker node is eligible if it is ready and does not have back pressure. |
| 142 | * |
| 143 | * @param workerNodeKey - The worker node key. |
| 144 | * @returns `true` if the worker node is eligible, `false` otherwise. |
| 145 | * @see {@link isWorkerNodeReady} |
| 146 | * @see {@link hasWorkerNodeBackPressure} |
| 147 | */ |
| 148 | protected isWorkerNodeEligible (workerNodeKey: number): boolean { |
| 149 | return ( |
| 150 | this.isWorkerNodeReady(workerNodeKey) && |
| 151 | !this.hasWorkerNodeBackPressure(workerNodeKey) |
| 152 | ) |
| 153 | } |
| 154 | |
| 155 | /** |
| 156 | * Gets the worker task runtime. |
| 157 | * If the task statistics require the average runtime, the average runtime is returned. |
| 158 | * If the task statistics require the median runtime , the median runtime is returned. |
| 159 | * |
| 160 | * @param workerNodeKey - The worker node key. |
| 161 | * @returns The worker task runtime. |
| 162 | */ |
| 163 | protected getWorkerTaskRunTime (workerNodeKey: number): number { |
| 164 | return this.taskStatisticsRequirements.runTime.median |
| 165 | ? this.pool.workerNodes[workerNodeKey].usage.runTime?.median ?? 0 |
| 166 | : this.pool.workerNodes[workerNodeKey].usage.runTime?.average ?? 0 |
| 167 | } |
| 168 | |
| 169 | /** |
| 170 | * Gets the worker task wait time. |
| 171 | * If the task statistics require the average wait time, the average wait time is returned. |
| 172 | * If the task statistics require the median wait time, the median wait time is returned. |
| 173 | * |
| 174 | * @param workerNodeKey - The worker node key. |
| 175 | * @returns The worker task wait time. |
| 176 | */ |
| 177 | protected getWorkerTaskWaitTime (workerNodeKey: number): number { |
| 178 | return this.taskStatisticsRequirements.waitTime.median |
| 179 | ? this.pool.workerNodes[workerNodeKey].usage.waitTime?.median ?? 0 |
| 180 | : this.pool.workerNodes[workerNodeKey].usage.waitTime?.average ?? 0 |
| 181 | } |
| 182 | |
| 183 | /** |
| 184 | * Gets the worker task ELU. |
| 185 | * If the task statistics require the average ELU, the average ELU is returned. |
| 186 | * If the task statistics require the median ELU, the median ELU is returned. |
| 187 | * |
| 188 | * @param workerNodeKey - The worker node key. |
| 189 | * @returns The worker task ELU. |
| 190 | */ |
| 191 | protected getWorkerTaskElu (workerNodeKey: number): number { |
| 192 | return this.taskStatisticsRequirements.elu.median |
| 193 | ? this.pool.workerNodes[workerNodeKey].usage.elu.active?.median ?? 0 |
| 194 | : this.pool.workerNodes[workerNodeKey].usage.elu.active?.average ?? 0 |
| 195 | } |
| 196 | |
| 197 | /** |
| 198 | * Sets safely the previous worker node key. |
| 199 | * |
| 200 | * @param workerNodeKey - The worker node key. |
| 201 | */ |
| 202 | protected setPreviousWorkerNodeKey (workerNodeKey: number | undefined): void { |
| 203 | this.previousWorkerNodeKey = workerNodeKey ?? this.previousWorkerNodeKey |
| 204 | } |
| 205 | |
| 206 | /** |
| 207 | * Check the next worker node eligibility. |
| 208 | */ |
| 209 | protected checkNextWorkerNodeEligibility (): void { |
| 210 | if (!this.isWorkerNodeEligible(this.nextWorkerNodeKey as number)) { |
| 211 | this.nextWorkerNodeKey = undefined |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | protected computeDefaultWorkerWeight (): number { |
| 216 | let cpusCycleTimeWeight = 0 |
| 217 | for (const cpu of cpus()) { |
| 218 | // CPU estimated cycle time |
| 219 | const numberOfDigits = cpu.speed.toString().length - 1 |
| 220 | const cpuCycleTime = 1 / (cpu.speed / Math.pow(10, numberOfDigits)) |
| 221 | cpusCycleTimeWeight += cpuCycleTime * Math.pow(10, numberOfDigits) |
| 222 | } |
| 223 | return Math.round(cpusCycleTimeWeight / cpus().length) |
| 224 | } |
| 225 | } |