This DNS name and load-balancing architecture shows how to use a Route 53 can be used to send traffic to both an on-premises server and an EC2 deployment. The health checks on Route 53 records (for example-on-prem.xxx.cucloud.net and example-nlb.xxx.cucloud.net) ensure that Route 53 will respond with records that are actually functional.
Draw.io Diagram File: nlb-r53-architecture.drawio
Notes
- This scheme implements weighted round-robin traffic routing at the top level. However, individual clients (e.g. servers) are likely to cache DNS results which will reduce the effectiveness that some clients experience in the event of a failure of the on-premises system (if they were routed to the on-premises system).
Open Questions
- Will the health check for example-nlb.xxx.cucloud.net fail when none of the backend EC2 instances are running? We want it to fail in that case, since we don't want any traffic to be sent there.