Package org.springframework.retry.backoff

Class ExponentialRandomBackOffPolicy

java.lang.Object
org.springframework.retry.backoff.ExponentialBackOffPolicy
org.springframework.retry.backoff.ExponentialRandomBackOffPolicy
All Implemented Interfaces:
BackOffPolicy, SleepingBackOffPolicy<ExponentialBackOffPolicy>
public class ExponentialRandomBackOffPolicy extends ExponentialBackOffPolicy
Implementation of ExponentialBackOffPolicy that chooses a random multiple of the interval that would come from a simple deterministic exponential. The random multiple is uniformly distributed between 1 and the deterministic multiplier (so in practice the interval is somewhere between the next and next but one intervals in the deterministic case). This is often referred to as jitter. This has shown to at least be useful in testing scenarios where excessive contention is generated by the test needing many retries. In test, usually threads are started at the same time, and thus stomp together onto the next interval. Using this BackOffPolicy can help avoid that scenario. Example: initialInterval = 50 multiplier = 2.0 maxInterval = 3000 numRetries = 5 ExponentialBackOffPolicy yields: [50, 100, 200, 400, 800] ExponentialRandomBackOffPolicy may yield [76, 151, 304, 580, 901] or [53, 190, 267, 451, 815] (random distributed values within the ranges of [50-100, 100-200, 200-400, 400-800, 800-1600])
Author:
Jon Travis, Dave Syer, Chase Diem