The retry policy for one response, shared by the engine and obtainKey(): how
long to wait before the next try, or undefined when the response is not
retried. Only a transient 429/503 is retried, and only while attempt (retries
done so far) is below maxRetries. The normal backoff, retryDelayMs × (attempt + 1), is the floor: a Retry-After can lengthen a wait, never shorten it
(Retry-After: 0 or a date in the past would turn the retries into a zero-delay
burst against a server that has just asked for less load). A Retry-After above
MAX_RETRY_AFTER_MS is not retried at all (see retryAfterTooLong).
The retry policy for one response, shared by the engine and obtainKey(): how long to wait before the next try, or
undefinedwhen the response is not retried. Only a transient 429/503 is retried, and only whileattempt(retries done so far) is belowmaxRetries. The normal backoff,retryDelayMs × (attempt + 1), is the floor: aRetry-Aftercan lengthen a wait, never shorten it (Retry-After: 0or a date in the past would turn the retries into a zero-delay burst against a server that has just asked for less load). ARetry-AfteraboveMAX_RETRY_AFTER_MSis not retried at all (seeretryAfterTooLong).