Retry policy
When a delivery fails (non-2xx or network error), Harbor retries with exponential backoff. The default schedule is roughly 30s, 2m, 10m, 1h, 6h, 24h — each with ±20% jitter to avoid thundering herds. You can override this per destination: set max_retries, the base delay, the cap, and the total time budget. Destinations that consistently fail can be configured to circuit-break (pause automatically) after N consecutive failures.
What to know
Section titled “What to know”- 2xx = success. 5xx = retry. 4xx = retry ONLY IF the response header
Harbor-Retry-Hint: trueis present (otherwise dead-letter immediately). - Timeouts, connection refused, TLS errors = retry.
- The total time budget is a hard ceiling — once it elapses, the delivery goes to the dead-letter queue regardless of remaining retries.
- Circuit breaker: if a destination has 50+ consecutive failed deliveries, it’s auto-paused and you get an email. New events to that destination are queued for 1 hour before dead-lettering.