My Read Replica appears “stuck” after a Multi-AZ failover and is unable to obtain or apply updates from the
source DB Instance. What do I do?
A.
You will need to delete the Read Replica and create a new one to replace it.
B.
You will need to disassociate the DB Engine and re associate it.
C.
The instance should be deployed to Single AZ and then moved to Multi- AZ once again
D.
You will need to delete the DB Instance and create a new one to replace it.
A
https://aws.amazon.com/rds/mysql/faqs/
http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_ReadRepl.html#USER_ReadRepl.MySQL
For MySQL and MariaDB DB instances, in some cases Read Replicas cannot be switched to the secondary if some binlog events are not flushed during the failure. In these cases, you must manually delete and recreate the Read Replicas.
Other answers are senseless anyway.