Retries
Retry schedule, response handling, and recovery.
Network errors, timeouts, 408, 429, and 5xx retry after approximately 10 seconds, 30 seconds, 5 minutes, 30 minutes, 2 hours, 12 hours, then 24 hours, up to ten attempts per delivery cycle. Other 4xx and all 3xx responses are terminal. Manual redelivery opens a new cycle without changing the event ID.
SQL stores due time, attempts, snapshots, and leases. Redis is only a delivery hint, so lost queue state is recovered.