Backups
Backups
- Automated Backups as well as Snapshots are stored in S3
- The S3 buckets are AWS managed, hence not visible in user accounts
- Snapshots are manually generated Backups.
- Snapshots and Backups are of the instance and not a specific database
- First Snapshot is a full snapshot. All snapshots then onwards are incremental
- Snapshots don't expire & need to be manually deleted. They survive deletion of the instance
- Automated Backups happen once per day. The backup window is defined per instance.
- Every 5 minutes, database transaction logs are stored to S3
- Automated Backups are deleted automatically by AWS depending on retention period.
- Retention period could be 0 i.e. automated backups disabled or upto 35 days
- Backups can be copied cross region. This is not default & needs to be enabled explicitly
Restore
- While performing a restore, RDS first creates a new RDS Instance with new address
- While restoring from Automated Backups, one can restore it upto a precise 5 minute window
- First closest Snapshot is restored and then transaction logs are applied till the target timestamp
- RDS restores can take time. Hence RTO is larger