11. What happens when I convert my RDS instance from Single-AZ to Multi-AZ ?
For the RDS for MySQL, MariaDB, PostgreSQL and Oracle database engines, when you elect to convert your RDS instance from Single-AZ to Multi-AZ, the following happens:
A snapshot of your primary instance is taken
A new standby instance is created in a different Availability Zone, from the snapshot
Synchronous replication is configured between primary and standby instances
As such, there should be no downtime incurred when an instance is converted from Single-AZ to Multi-AZ. However, you may see increased latency while the data on the standby is caught up to match to the primary.
12. What events would cause Amazon RDS to initiate a failover to the standby replica ?
Amazon RDS detects and automatically recovers from the most common failure scenarios for Multi-AZ deployments so that you can resume database operations as quickly as possible without administrative intervention. Amazon RDS automatically performs a failover in the event of any of the following:
Loss of availability in primary Availability Zone
Loss of network connectivity to primary
Compute unit failure on primary
Storage failure on primary
13. How do DB Snapshots and automated backups work with my Multi-AZ deployment ?
You interact with automated backup and DB Snapshot functionality in the same way whether you are running a standard deployment in a Single-AZ or Multi-AZ deployment. If you are running a Multi-AZ deployment, automated backups and DB Snapshots are simply taken from the standby to avoid I/O suspension on the primary.
14. Can I set up alarms and notifications based on specific metrics ?
Yes. You can create an alarm in CloudWatch that sends a notification when the alarm changes state. The alarm watches a single metric over a time period that you specify, and performs one or more actions based on the value of the metric relative to the specified threshold over a number of time periods.
15. What is Amazon RDS Proxy ?
Amazon RDS Proxy is a fully managed, highly available database proxy feature for Amazon RDS. RDS Proxy makes applications more scalable, more resilient to database failures, and more secure.