RDS Cheat Sheet

• Relational Database Service (RDS) is the AWS Solution for relational databases.
• RDS instances are managed by AWS, You cannot SSH into the VM running the database.
• There are 6 relational database options currently available on AWS, Aurora, MySQL, Maria DB, Postgres, Oracle, Microsoft SQL Server
• Multi-AZ is an option you can turn on which makes an exact copy of your database in another AZ that is only standby
• For Multi-AZ AWS automatically synchronizes changes in the database over to the standby copy
• Multi-AZ has Automatic Failover protection if one AZ goes down failover will occur and the standby slave will be promoted to master
• Read-Replicas allow you to run multiples copies of your database, these copies only allows reads (no writes) and is intended to alleviate the workload of your primary database to improve performance
• Read-Replicas use Asynchronous replication
• You must have automatic backups enabled to use Read Replicas
• You can have upto 5 read replicas
• You can combine Read Replicas with Multi-AZ
• You can have Read Replicas in another Region (Cross-Region Read Replicas)
• Replicas can be promoted to their own database, but this breaks replication
• You can have Replicas of Read Replicas
• RDS has 2 backup solutions: Automated Backups and Database Snapshots
• Automated Backups, you choose a retention period between 1 and 35 days, There is no additional cost for backup storage, you define your backup window
• Manual Snapshots, you manually create backups, if you delete your primary the manual snapshots will still exist and can be restored
• When you restore an instance it will create a new database. You just need to delete your old database and point traffic to new restored database
• You can turn on encryption at-rest for RDS via KMS