> If you have the setup on 3 AZs how would you route traffic only to the AZ where your RDS resides?
So specifically for RDS, AWS will provide two endpoint for the client application: A writer and a reader endpoint. Similar to this:
mydbcluster.cluster-c7tj4example.us-east-1.rds.amazonaws.com : Writer endpoint
mydbcluster.cluster-ro-c7tj4example.us-east-1.rds.amazonaws.com : Reader endpoint (notice -ro part).
The writer endpoint will always resolve to the active master, which is what the client application is configured to use, and thats the hostname my lookup service will use as input to determine the current location of the Writer instance.
My solution works only for hostnames that returns a single IP address, so it won't work for the Reader endpoints. As I wrote in the repository, a requirement for this is that "The FQDN needs to return a single A record for the external resource".
> If you have the setup on 3 AZs how would you route traffic only to the AZ where your RDS resides?
So specifically for RDS, AWS will provide two endpoint for the client application: A writer and a reader endpoint. Similar to this: mydbcluster.cluster-c7tj4example.us-east-1.rds.amazonaws.com : Writer endpoint mydbcluster.cluster-ro-c7tj4example.us-east-1.rds.amazonaws.com : Reader endpoint (notice -ro part).
The writer endpoint will always resolve to the active master, which is what the client application is configured to use, and thats the hostname my lookup service will use as input to determine the current location of the Writer instance.
My solution works only for hostnames that returns a single IP address, so it won't work for the Reader endpoints. As I wrote in the repository, a requirement for this is that "The FQDN needs to return a single A record for the external resource".