See if this helps:
A request that fails can be retried with an exponential backoff and Jitter strategy or it could be stored in a queue for later processing. For front-end interfaces, it might be possible to provide alternative or cached content instead of failing completely when, for example, your database server becomes unavailable. The Amazon Route 53 DNS failover feature also gives you the ability to monitor your website and automatically route your visitors to a backup site if your primary site becomes unavailable. You can host your backup site as a static website on Amazon S3 or as a separate dynamic environment.