A stateless highly available application is developed using Amazon RDS & Elasticache. DB instance is set up in different AZ of the us-west-1 region. Since this is a critical application, the operations director is looking for failover scenarios in which the application will failover to standby DB instance. Which of the following is not a possible reason when RDS primary instance failover to standby? (Select Two).

Answer options:

A.Long-running queries on primary DB instance.
B.Connectivity issues at primary AZ.
C.Hardware Failure of primary DB instance.
D.Storage failure on primary DB instance.
E.Database Corruption errors

Correct Answers: A and E
In case of long-running queues or Database corruption error, Amazon Primary Instance will not automatically failover to standby instance in different AZ. You need to manually failover to standby DB instance.
Options B, C, D are incorrect as in these cases, Amazon RDS automatically failover to standby DB instance in different AZ.
For more information on failover scenarios for Amazon RDS, refer to the following URL-
https://aws.amazon.com/rds/faqs/