src/pools/selection-strategies/selection-strategies-types.ts

   1 /**
   2  * Enumeration of worker choice strategies.
   3  */
   4 export const WorkerChoiceStrategies = Object.freeze({
   5   /**
   6    * Round robin worker selection strategy.
   7    */
   8   ROUND_ROBIN: 'ROUND_ROBIN',
   9   /**
  10    * Least used worker selection strategy.
  11    */
  12   LEAST_USED: 'LEAST_USED',
  13   /**
  14    * Least busy worker selection strategy.
  15    */
  16   LEAST_BUSY: 'LEAST_BUSY',
  17   /**
  18    * Least ELU worker selection strategy.
  19    *
  20    * @experimental
  21    */
  22   LEAST_ELU: 'LEAST_ELU',
  23   /**
  24    * Fair share worker selection strategy.
  25    */
  26   FAIR_SHARE: 'FAIR_SHARE',
  27   /**
  28    * Weighted round robin worker selection strategy.
  29    */
  30   WEIGHTED_ROUND_ROBIN: 'WEIGHTED_ROUND_ROBIN',
  31   /**
  32    * Interleaved weighted round robin worker selection strategy.
  33    *
  34    * @experimental
  35    */
  36   INTERLEAVED_WEIGHTED_ROUND_ROBIN: 'INTERLEAVED_WEIGHTED_ROUND_ROBIN'
  37 } as const)
  38
  39 /**
  40  * Worker choice strategy.
  41  */
  42 export type WorkerChoiceStrategy = keyof typeof WorkerChoiceStrategies
  43
  44 /**
  45  * Measurement options.
  46  */
  47 interface MeasurementOptions {
  48   /**
  49    * Set measurement median.
  50    */
  51   median: boolean
  52 }
  53
  54 /**
  55  * Worker choice strategy options.
  56  */
  57 export interface WorkerChoiceStrategyOptions {
  58   /**
  59    * Runtime options.
  60    *
  61    * @defaultValue \{ median: false \}
  62    */
  63   runTime?: MeasurementOptions
  64   /**
  65    * Wait time options.
  66    *
  67    * @defaultValue \{ median: false \}
  68    */
  69   waitTime?: MeasurementOptions
  70   /**
  71    * Event loop utilization options.
  72    *
  73    * @defaultValue \{ median: false \}
  74    */
  75   elu?: MeasurementOptions
  76   /**
  77    * Worker weights to use for weighted round robin worker selection strategy.
  78    * Weight is the tasks maximum average or median runtime in milliseconds.
  79    *
  80    * @defaultValue Computed worker weights automatically given the CPU performance.
  81    */
  82   weights?: Record<number, number>
  83 }
  84
  85 /**
  86  * Measurement statistics requirements.
  87  *
  88  * @internal
  89  */
  90 interface MeasurementStatisticsRequirements {
  91   /**
  92    * Require measurement aggregate.
  93    */
  94   aggregate: boolean
  95   /**
  96    * Require measurement average.
  97    */
  98   average: boolean
  99   /**
 100    * Require measurement median.
 101    */
 102   median: boolean
 103 }
 104
 105 /**
 106  * Pool worker node worker usage statistics requirements.
 107  *
 108  * @internal
 109  */
 110 export interface TaskStatisticsRequirements {
 111   /**
 112    * Tasks runtime requirements.
 113    */
 114   runTime: MeasurementStatisticsRequirements
 115   /**
 116    * Tasks wait time requirements.
 117    */
 118   waitTime: MeasurementStatisticsRequirements
 119   /**
 120    * Tasks event loop utilization requirements.
 121    */
 122   elu: MeasurementStatisticsRequirements
 123 }
 124
 125 /**
 126  * Worker choice strategy interface.
 127  */
 128 export interface IWorkerChoiceStrategy {
 129   /**
 130    * Tasks statistics requirements.
 131    */
 132   readonly taskStatisticsRequirements: TaskStatisticsRequirements
 133   /**
 134    * Resets strategy internals.
 135    *
 136    * @returns `true` if the reset is successful, `false` otherwise.
 137    */
 138   reset: () => boolean
 139   /**
 140    * Updates the worker node key strategy internals.
 141    *
 142    * @returns `true` if the update is successful, `false` otherwise.
 143    */
 144   update: (workerNodeKey: number) => boolean
 145   /**
 146    * Chooses a worker node in the pool and returns its key.
 147    *
 148    * @returns The worker node key.
 149    */
 150   choose: () => number
 151   /**
 152    * Removes the worker node key from strategy internals.
 153    *
 154    * @param workerNodeKey - The worker node key.
 155    * @returns `true` if the worker node key is removed, `false` otherwise.
 156    */
 157   remove: (workerNodeKey: number) => boolean
 158   /**
 159    * Sets the worker choice strategy options.
 160    *
 161    * @param opts - The worker choice strategy options.
 162    */
 163   setOptions: (opts: WorkerChoiceStrategyOptions) => void
 164 }