RDS 24 runs community MySQL 524 on an EC2 24 instance you never see, with its data on EBS 24 (EBS Volumes and Snapshots). Ask the API which versions it sells; this call only reads, so it costs nothing:
aws rds describe-db-engine-versions --engine mysql --region us-east-1 --output text \
--query "join(' ', DBEngineVersions[?starts_with(EngineVersion, '8.4')].EngineVersion)"8.4.5 8.4.6 8.4.7 8.4.8 8.4.9 8.4.10 8.4.11
The default for new instances was 8.4.9, not the newest, so name the version. MySQL 8.0 left RDS standard support on 31 July 2026 and now runs only under paid Extended Support; 8.4 is supported until 31 July 2029. The next command is shown without output because it starts billing the account the moment it succeeds:
aws rds create-db-instance --db-instance-identifier shop-db --engine mysql \
--engine-version 8.4.11 --db-instance-class db.t4g.micro --storage-type gp3 \
--allocated-storage 20 --backup-retention-period 7 --master-username admin \
--manage-master-user-password --no-publicly-accessible--manage-master-user-password keeps the password in AWS Secrets Manager 24 , and --no-publicly-accessible limits connections to your VPC: open port 3306 in the instance's security group to the web server's group only (Security Groups). Add --multi-az for production. It keeps a synchronous standby in a second Availability Zone and fails over by repointing the endpoint's DNS name, so connect by name, never by IP. Prices in us-east-1 on 23 September 2026: db.t4g.micro USD 0.016 an hour (0.032 Multi-AZ) and gp3 USD 0.115 per GB-month, about USD 14 a month for this command.