Amazon RDS Read Replicas for PostgreSQL can now be deployed in a Multi-AZ configuration.
Amazon RDS offers Multi-AZ deployments and Read Replicas to support availability, scalability, and disaster recovery requirements for production databases. Now, with the ability to deploy Read Replicas in a Multi-AZ configuration, you can have more resilient Read Replicas, improved DR strategy, and a simplified engine upgrade process with high availability.
For many read-heavy workloads, including analytics and OLTP, serving read requests is considered business critical. Having a standby Read Replica in a Multi-AZ configuration ensures high availability for the Read Replica. In the event of the Read Replica host failure or even an AZ failure, the Multi-AZ standby is activated automatically, and the read requests are served from the new server.
In the event of source production database failure, a Read Replica with Multi-AZ can be promoted to become the new production database, and the new production database is instantly highly available, as it is already configured with Multi-AZ.
During the database upgrade process, a Read Replica in a Multi-AZ configuration can be first upgraded to a new database engine version, and then promoted to a production database instance. Since that instance is configured with Multi-AZ, it already has high availability to serve your mission critical application requirements.
For more information, see the Amazon RDS User Guide.