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    * Worker weights to use for weighted round robin worker selection strategy.
  72    * Weight is the tasks maximum average or median runtime in milliseconds.
  73    *
  74    * @defaultValue Computed worker weights automatically given the CPU performance.
  75    */
  76   weights?: Record<number, number>
  77 }
  78
  79 /**
  80  * Measurement statistics requirements.
  81  *
  82  * @internal
  83  */
  84 interface MeasurementStatisticsRequirements {
  85   /**
  86    * Require measurement aggregate.
  87    */
  88   aggregate: boolean
  89   /**
  90    * Require measurement average.
  91    */
  92   average: boolean
  93   /**
  94    * Require measurement median.
  95    */
  96   median: boolean
  97 }
  98
  99 /**
 100  * Pool worker node worker usage statistics requirements.
 101  *
 102  * @internal
 103  */
 104 export interface TaskStatisticsRequirements {
 105   /**
 106    * Tasks runtime requirements.
 107    */
 108   runTime: MeasurementStatisticsRequirements
 109   /**
 110    * Tasks wait time requirements.
 111    */
 112   waitTime: MeasurementStatisticsRequirements
 113   /**
 114    * Event loop utilization.
 115    */
 116   elu: boolean
 117 }
 118
 119 /**
 120  * Worker choice strategy interface.
 121  */
 122 export interface IWorkerChoiceStrategy {
 123   /**
 124    * Tasks statistics requirements.
 125    */
 126   readonly taskStatisticsRequirements: TaskStatisticsRequirements
 127   /**
 128    * Resets strategy internals.
 129    *
 130    * @returns `true` if the reset is successful, `false` otherwise.
 131    */
 132   reset: () => boolean
 133   /**
 134    * Updates the worker node key strategy internals.
 135    *
 136    * @returns `true` if the update is successful, `false` otherwise.
 137    */
 138   update: (workerNodeKey: number) => boolean
 139   /**
 140    * Chooses a worker node in the pool and returns its key.
 141    *
 142    * @returns The worker node key.
 143    */
 144   choose: () => number
 145   /**
 146    * Removes the worker node key from strategy internals.
 147    *
 148    * @param workerNodeKey - The worker node key.
 149    * @returns `true` if the worker node key is removed, `false` otherwise.
 150    */
 151   remove: (workerNodeKey: number) => boolean
 152   /**
 153    * Sets the worker choice strategy options.
 154    *
 155    * @param opts - The worker choice strategy options.
 156    */
 157   setOptions: (opts: WorkerChoiceStrategyOptions) => void
 158 }