Source: util/exponential-backoff.ts

  1. /**
  2.  * @fileoverview Calculate exponential backoff time
  3.  */
  5. // ------------------------------------------------------------------------------
  6. // Private
  7. // ------------------------------------------------------------------------------
  9. // Retry intervals are between 50% and 150% of the exponentially increasing base amount
  10. const RETRY_RANDOMIZATION_FACTOR = 0.5;
  12. /**
  13.  * Calculate the exponential backoff time with randomized jitter
  14.  * @param {int} numRetries Which retry number this one will be
  15.  * @param {int} baseInterval The base retry interval set in config
  16.  * @returns {int} The number of milliseconds after which to retry
  17.  */
  18. export = function getRetryTimeout(numRetries: number, baseInterval: number) {
  19. 	var minRandomization = 1 - RETRY_RANDOMIZATION_FACTOR;
  20. 	var maxRandomization = 1 + RETRY_RANDOMIZATION_FACTOR;
  21. 	var randomization =
  22. 		Math.random() * (maxRandomization - minRandomization) + minRandomization;
  23. 	var exponential = Math.pow(2, numRetries - 1);
  24. 	return Math.ceil(exponential * baseInterval * randomization);
  25. };