RDS
- Expands to Relational Database Service
- Eliminates much of relational database management
- Can be scaled independently
- CPU
- memory
- storage
- IOPS
- AWS manages
- backups
- software patching
- automatic failure detection
- recovery
- Can trigger, manual or automated backups
- It provides high availability with primary instance which if fails, switch to secondary instance
- Has a soft limit of 40 Amazon RDS DB instances per account
- From 40, up to 10 can be Oracle or Microsoft SQL Server DB instances under the License Included model.
- Customers can Bring Your Own License (BYOL) model to have all 40 DB instances for Oracle or Microsoft SQL Server
- Supports database engines
- MySQL
- MariaDB
- PostgreSQL
- Oracle
- Microsoft SQL Server
- MySQL-compatible Amazon Aurora
- AWS IAM controls AWS resources access to Amazon RDS databases.
- For security
- put database in an Amazon Virtual Private Cloud (Amazon VPC)
- using Secure Sockets Layer (SSL) for data in transit
- Using encryption for data at rest
- RDS Management by
- RDS APIs
- AWS Management Console
- Both are used to
- Create RDS DB instances
- Delete RDS DB instances
- Modify RDS DB instances
- terminate RDS DB instances
- create DB snapshots
- perform restores
- Amazon RDS has no data API
- DNS endpoint is given for database connection after database creation
- Endpoint does not change over the lifetime of the instance even during the failover in case of Multi-AZ configuration
- EBS volumes are used as data store by RDS
- database backups in RDS are replicated in multiple AZs
- synchronous replication is done amongst primary and standby instance
- DNS endpoint switches to standby instance during primary failure
- Read replicas are also provided by RDS
- asynchronous replication is done
- only for supported databases
- RDS Provisioned IOPS, where the IOPS can be specified when the instance is launched and is guaranteed over the life of the instance
AWS RDS limits per region
| Resource | Default Limit |
| Maximum Cross-region snapshots copy requests | 5 |
| Maximum DB Instances | 40 |
| Maximum Event subscriptions | 20 |
| Total Manual snapshots | 100 |
| Count of Option groups | 20 |
| Count of Parameter groups | 50 |
| Count of Read replicas per master | 5 |
| Count of Reserved instances | 40 |
| Count of Rules/DB security group | 20 |
| Count of Rules/VPC security group | 50 inbound 50 outbound |
| Count of DB Security groups | 25 |
| Count of VPC Security groups | 5 |
| Count of Subnet groups | 50 |
| Count of Subnets per subnet group | 20 |
| Count of Tags/resource | 50 |
| Total storage for all DB instances | 100 TiB |
