Is it possible to tap into a Multi-AZ DB cluster read replica binlog?

Before, a MySQL DB instance can serve as a replication source, make sure to enable automatic backups on the source DB instance. To do this, set the backup retention period to a value other than 0.

NOW This requirement also applies to a read replica that is the source DB instance for another read replica. Automatic backups are supported for read replicas running any version of MySQL. You can configure replication based on binary log coordinates for a MySQL DB instance.

[+] For More Information, see: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_MySQL.Replication.ReadReplicas.html#USER_MySQL.Replication.ReadReplicas.Configuration

RDS for MySQL supports cascading read replicas. With cascading read replicas, your RDS for MySQL DB instance sends data to the first read replica in the chain. That read replica then sends data to the second replica in the chain, and so on. The end result is that all read replicas in the chain have the changes from the RDS for MySQL DB instance, but without the overhead solely on the source DB instance.

On RDS for MySQL version 5.7.23 and higher MySQL 5.7 versions and RDS for MySQL 8.0.26 and higher 8.0 versions, you can configure replication using global transaction identifiers (Global transaction identifiers (GTIDs) are unique identifiers generated for committed MySQL transactions. You can use GTIDs to make binlog replication simpler and easier to troubleshoot.)

[+] For Setting Up GTIDs, see: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/mysql-replication-gtid.html