How does RDS Multi-AZ Fail Over Update DNS Records

Question

Hi all,

If automatic fail over of a multi-AZ RDS instance happens by updating DNS CNAMEs, can someone explain how and what is updated by RDS?  Where are the CNAMEs located that are updated?  And how does RDS have access to update them?  Does this only work for private R53 zones?  Is there a separate zone created only for RDS?  I can't find specifics in any documentation.  All I can find is "DNS is updated" and suggestions for lowering JVM TTLs to account for this.  Can someone please provide a detailed explanation?  Thanks!

Gary Mclean · Accepted Answer

The RDS endpoint DNS is managed by AWS. You do not have access to view or update this  DNS record.

In the event of a Multi AZ failover, AWS will update this DNS record.

If your application doesn’t adhere to DNS lookups then you should look at using the RDS proxy.

Either way the RDS proxy can improve failover times as the proxy handles the failover in a Multi AZ failover event resolution where the proxy IP doesn’t change.

How does RDS Multi-AZ Fail Over Update DNS Records

Add your answer

Relevant content