Question
A company is using an Amazon Aurora cluster as the data store for its application. The Aurora cluster is configured with a single DB instance. The application performs read and write operations on the database by using the cluster's instance endpoint.
The company has scheduled an update to be applied to the cluster during an upcoming maintenance window. The cluster must remain available with the least possible interruption during the maintenance window.
What should a DevOps engineer do to meet these requirements?
- A. Add a reader instance to the Aurora cluster. Update the application to use the Aurora cluster endpoint for write operations. Update the Aurora cluster's reader endpoint for reads. Correct
- B. Add a reader instance to the Aurora cluster. Create a custom ANY endpoint for the cluster. Update the application to use the Aurora cluster's custom ANY endpoint for read and write operations.
- C. Turn on the Multi-AZ option on the Aurora cluster. Update the application to use the Aurora cluster endpoint for write operations. Update the Aurora cluster’s reader endpoint for reads.
- D. Turn on the Multi-AZ option on the Aurora cluster. Create a custom ANY endpoint for the cluster. Update the application to use the Aurora cluster's custom ANY endpoint for read and write operations
Explanation
A is correct. Adding a reader instance (Aurora Replica) gives the cluster a failover target, so if the writer becomes unavailable during maintenance Aurora promotes the replica. The application currently uses an instance endpoint, which always points to one DB instance and does not follow a failover. The cluster endpoint always points to the current writer, so after a failover writes go to the new writer automatically, and the reader endpoint spreads reads across the replicas. C and D are wrong because an Aurora cluster has no Multi-AZ option to turn on; Aurora gets Multi-AZ availability by adding replicas in other Availability Zones. B is wrong because a custom endpoint is meant for groups of instances serving reads and does not reliably send writes to the writer.
