A database instance is a provisioned runtime deployment of a database engine with allocated compute, memory, and storage. In Amazon RDS, the instance runs an engine such as MySQL and exposes an endpoint that applications use for SQL queries. section 10.1.1 section 10.1.2
Launching one involves provisioning the instance and then connecting an application to its endpoint. A WordPress deployment uses CloudFormation to create the RDS instance alongside web servers, while an EC2 host in the same VPC connects to it. section 10.1.1
Configure an RDS database instance with:
- Private network access through a security group; internet exposure is possible but generally discouraged. section 10.1.1
Inspecting the endpoint
After provisioning, retrieve the endpoint and port with aws rds describe-db-instances --query "DBInstances[0].Endpoint". An application sends SQL such as SELECT * FROM table to that endpoint. section 10.1.2
RDS costs depend on the instance size and allocated storage, and cost more than an equivalent database on plain EC2. The managed service offsets that premium by handling installation, patching, upgrades, migration, backups, and recovery. section 10.1.3
