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. The random multiple is selected based on how many iterations have occurred. 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 [50, 100, 100, 100, 600] or [50, 100, 150, 400, 800]

Author:

Jon Travis, Dave Syer

Field Summary

Fields inherited from class org.springframework.retry.backoff.ExponentialBackOffPolicy

DEFAULT_INITIAL_INTERVAL, DEFAULT_MAX_INTERVAL, DEFAULT_MULTIPLIER, logger

Constructor Summary

ExponentialRandomBackOffPolicy()

Method Summary

protected ExponentialBackOffPolicy	newInstance()
BackOffContext	start(RetryContext context) Returns a new instance of BackOffContext, seeded with this policies settings.

Methods inherited from class org.springframework.retry.backoff.ExponentialBackOffPolicy

backOff, cloneValues, getInitialInterval, getMaxInterval, getMultiplier, setInitialInterval, setMaxInterval, setMultiplier, setSleeper, toString, withSleeper

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ExponentialRandomBackOffPolicy

public ExponentialRandomBackOffPolicy()

Method Detail

start

public BackOffContext start(RetryContext context)

Returns a new instance of BackOffContext, seeded with this policies settings.

Specified by:

start in interface BackOffPolicy

Overrides:

start in class ExponentialBackOffPolicy

Parameters:

context - the current retry context, which might contain information that we can use to decide how to proceed.

Returns:

the implementation-specific BackOffContext or 'null'.

newInstance

protected ExponentialBackOffPolicy newInstance()

Overrides:

newInstance in class ExponentialBackOffPolicy