A solution architect would like to improve the disaster recovery capability of an Amazon Aurora database cluster by creating additional read-replicas in a secondary AWS region. What is the optimal solution to implement this requirement?

Answer options:

A.Create an Amazon Aurora cluster in the target AWS region. Create an AWS Glue job to perform data copy from the source Amazon Aurora cluster to the target Amazon Aurora cluster. Create a cron expression to define a time-based schedule for the AWS Glue job.
B.Create a Lambda function to create a snapshot of the source Amazon Aurora cluster, perform a cross-region copy of the snapshot, and load the snapshot into the target Amazon Aurora cluster.
C.Configure VPC Peering between the two VPC’s in the two AWS regions. Create a cross-region read replica in the target AWS region.
D.Configure binlog_format parameter for the source Amazon Aurora cluster. Create a cross-region read replica in the target AWS region.

Answer: D
Option A is incorrect because this is not an optimal solution. Implementing a custom AWS Glue job to perform data copy introduces complexity. Further, the target Amazon Aurora cluster would have a primary instance that is write capable, leading to potential data drift compared to the source cluster. Finally, triggering the glue job using a cron expression can lead to a significant delay in data synchronization.
Option B is incorrect because this is not an optimal solution. Implementing a custom AWS Lambda function introduces complexity. Additionally, creating, copying and restoring a database from a snapshot is a very time-consuming activity. Further, the target Amazon Aurora cluster would have a primary instance that is write capable, leading to potential data drift compared to the source cluster.
Option C is incorrect because VPC peering is not required. Instead, binary logging must be enabled and configured on the source database.
Option D is CORRECT because it can create up to five cross-region read replicas of a source Amazon Aurora cluster. A requirement for this is to enable and configure binary logging on the source database cluster. This can be done by setting the binlog_format parameter on the source database cluster.
Reference:
https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.Replication.CrossRegion.html