Posted On: Nov 23, 2021

Amazon Relational Database Service (Amazon RDS) for MySQL and for PostgreSQL now supports a new Multi-AZ deployment option with one primary and two readable standby database instances. This deployment option optimizes write transactions and is ideal when your workloads require additional read capacity, lower write transaction latency, more resilience from network jitter (which impacts the consistency of write transaction latency), and high availability and durability.

Amazon RDS Multi-AZ deployments provide enhanced availability and durability for Amazon RDS database (DB) instances, making them a natural fit for production database workloads. In a Multi-AZ deployment of a DB instance, Amazon RDS automatically creates a primary DB instance and replicates the data to a standby DB instance in a different Availability Zone (AZ). In the case of an infrastructure failure, Amazon RDS performs an automatic failover to the standby, so that database operations resume as soon as the failover is complete. Since the endpoint for the DB Instance remains the same after a failover, the application can resume database operations without the need for manual administrative intervention.

Now, Amazon RDS offers a second Multi-AZ deployment option—a Multi-AZ deployment with readable standby DB instances. When you select this new option, Amazon RDS provisions one primary and two standby DB instances across three AZs and then automatically configures data replication. The standby DB instances act as automatic failover targets and can also serve read traffic to increase throughput without needing to attach additional read replica DB instances. You can connect to your readable standby DB instances by using a managed read-only endpoint or the individual endpoints of each.

The readable standby option for Amazon RDS Multi-AZ deployments works with AWS Graviton2 R6gd and M6gd DB instances (with NVMe-based SSD instance storage) and Provisioned IOPS Database Storage. The Preview is available in the US East (N. Virginia), US West (Oregon), and Europe (Ireland) regions. Amazon RDS for MySQL supports the Multi-AZ readable standby option for MySQL version 8.0.26. Amazon RDS for PostgreSQL supports the Multi-AZ readable standby option for PostgreSQL version 13.4.

Learn more about Multi-AZ deployments in the Amazon RDS User Guide and in the AWS Database Blog. See Amazon RDS Pricing for pricing details. Create or update a fully managed Amazon RDS database in the Amazon RDS Management Console.