Read Replica

Up to 15 read replicas Within AZ, Cross AZ or Cross Region Replication is Async, reads are eventually consistent Replica can be promoted to their own db. I will keep living with its own life cycle later. App need to update connection string to connect new one For reporting application we can separately read read-replica only Network cost Within same region no fee for replication If spread across different regions, have to pay fee

Multi AZ(Disaster Recovery)

SYNC replication, One DNS name automatic app failover to standby Increase availability

Single AZ to Multi AZ

Zero downtime operation How it work under the hood

• Take snapshot, create new standby az
• Synchronization started

RDS custom

Managed MSQL server, oracle Have access to underlying os and db

• So can configure settings
• Install patches
• Can access underlying instance
• Deactivate automation mode to customize(better to take DB snapshot before) RDS vs RDS custom RDS: AWS manage RDS custom: full access to underlying database and OS

Backups

Automated backups

Daily full backup at the backup windows Transitions logs are backup every 5 minutes Ability to restore any point in time (from oldest backup up to 5 minutes) 1 to 35 days retentions, set 0 to disable backup

Manual DB snapshots

User manually take snapshot of aurora Retention can be as long as the user wants Tip: to save cost for stopped database, take snapshot and delete original database. Can use snapshot to restore data at anytime.

Restore

From s3 Backup on premise database Store backup on s3 Restore that backup from s3 on rdb running mysql