Why AWS RDS service needs two subnets from different AZs

Question

As part of our project we are using AWS RDS postgres service. While creating RDS service AWS mandated to create two su.nets from different AZs (ex: us-west-2a and us-west-2b). But we have only one su.net. Is there any way to overcome this problem.

Thanks in advance.

Answer 1

To ensure High Availability, you need to specify su.nets in two different Availability Zones (AZs).

Each AZ operates in a different data center. If an AZ fails, the Amazon RDS service will automatically launch a replacement database in a different AZ. Therefore, it requires a minimum of two different AZs to be specfiied.