How EventBridge retries delivering events

Sometimes an event isn't successfully delivered to the target specified in a rule. This can happen, for example:

• If the target resource is unavailable

• Due to network conditions

When an event isn't successfully delivered to a target because of retriable errors, EventBridge retries sending the event. You set the length of time it tries, and number of retry attempts in the Retry policy settings for the target. By default, EventBridge retries sending the event for 24 hours and up to 185 times with an exponential back off and jitter, or randomized delay.

If an event isn't delivered after all retry attempts are exhausted, the event is dropped and EventBridge doesn't continue to process it.

To avoid losing events after they fail to be delivered to a target, configure a dead-letter queue (DLQ) to receive all failed events. For more information, see Using dead-letter queues to process undelivered events in EventBridge.