Point 2 endpoints to the same private DNS name.

Question

Hi,

I have a question about a setup that I would like to create. Is it possible to create 2 endpoints (VPC endpoints) A and B where both use the same private DNS name but with different service names. How the DNS resolution work in this case ? Will the DNS resolution will be managed within AWS ? I mean will it test the first endpoint, say hey this does not work so let's try with the second one. And if it works, take the working one ? Thank you

Answer

I don't think this will work - here's my reasoning:

If you have a single DNS name (I suspect a CNAME record?) that (say) points to two different service names which relate to two different endpoints - when you resolved that single DNS name, how will DNS know which service name to respond with?

I suspect that you're thinking of Route 53 Health Checks which would be an interesting solution to the problem but it creates another issue:

The application will do a lookup for `single-dns-name.com` and that points to either `service-a.com` or `service-b.com`. DNS chooses `service-b.com` because that's the one that is healthy and returns the IP address for that. Now, the application connects to what it thinks is `single-dns-name.com` but is presented with an endpoint that identifies itself (presumably a certificate) that identifies the endpoint as `service-b.com` - and then things don't (generally) work.

Point 2 endpoints to the same private DNS name.

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