src/pools/selection-strategies/least-elu-worker-choice-strategy.ts

   1 import type { IPool } from '../pool.js'
   2 import { DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS } from '../utils.js'
   3 import type { IWorker } from '../worker.js'
   4 import { AbstractWorkerChoiceStrategy } from './abstract-worker-choice-strategy.js'
   5 import type {
   6   IWorkerChoiceStrategy,
   7   TaskStatisticsRequirements,
   8   WorkerChoiceStrategyOptions,
   9 } from './selection-strategies-types.js'
  10
  11 /**
  12  * Selects the worker with the least ELU.
  13  * @typeParam Worker - Type of worker which manages the strategy.
  14  * @typeParam Data - Type of data sent to the worker. This can only be structured-cloneable data.
  15  * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
  16  */
  17 export class LeastEluWorkerChoiceStrategy<
  18     Worker extends IWorker,
  19     Data = unknown,
  20     Response = unknown
  21   >
  22   extends AbstractWorkerChoiceStrategy<Worker, Data, Response>
  23   implements IWorkerChoiceStrategy {
  24   /** @inheritDoc */
  25   public readonly taskStatisticsRequirements: TaskStatisticsRequirements = {
  26     runTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
  27     waitTime: DEFAULT_MEASUREMENT_STATISTICS_REQUIREMENTS,
  28     elu: {
  29       aggregate: true,
  30       average: false,
  31       median: false,
  32     },
  33   }
  34
  35   /** @inheritDoc */
  36   public constructor (
  37     pool: IPool<Worker, Data, Response>,
  38     opts?: WorkerChoiceStrategyOptions
  39   ) {
  40     super(pool, opts)
  41     this.setTaskStatisticsRequirements(this.opts)
  42   }
  43
  44   /** @inheritDoc */
  45   public reset (): boolean {
  46     return true
  47   }
  48
  49   /** @inheritDoc */
  50   public update (): boolean {
  51     return true
  52   }
  53
  54   /** @inheritDoc */
  55   public choose (): number | undefined {
  56     this.setPreviousWorkerNodeKey(this.nextWorkerNodeKey)
  57     this.nextWorkerNodeKey = this.leastEluNextWorkerNodeKey()
  58     return this.nextWorkerNodeKey
  59   }
  60
  61   /** @inheritDoc */
  62   public remove (): boolean {
  63     return true
  64   }
  65
  66   private leastEluNextWorkerNodeKey (): number | undefined {
  67     return this.pool.workerNodes.reduce(
  68       (minWorkerNodeKey, workerNode, workerNodeKey, workerNodes) => {
  69         return this.isWorkerNodeReady(workerNodeKey) &&
  70           (workerNode.usage.elu.active.aggregate ?? 0) <
  71             (workerNodes[minWorkerNodeKey].usage.elu.active.aggregate ?? 0)
  72           ? workerNodeKey
  73           : minWorkerNodeKey
  74       },
  75       0
  76     )
  77   }
  78 }