Posted On: May 24, 2023
Amazon Relational Database Service (Amazon RDS) for PostgreSQL now supports up to 15 asynchronous read replicas from Amazon RDS Multi-AZ deployments with two readable standbys delivering up to 8x the previous read capacity.
Amazon RDS Multi-AZ deployments with two readable standbys have one writer instance and two readable standby instances across three availability zones. You can now create 15 additional asynchronous read replicas outside the cluster in addition to the two reader instances thereby scaling up your read capacity to 17 instances. Amazon RDS Read Replicas provide enhanced performance and durability for RDS database (DB) instances. For read heavy database workloads, the additional read replicas provide the option to elastically scale out beyond the capacity constraints of the two readable instances inside the Multi-AZ deployment with two readable standbys. You can create one or more read replicas and serve high-volume application read traffic from multiple copies of your data, thereby increasing aggregate read throughput. Read replicas can also be promoted and modified to be a Multi-AZ deployment option with two readable standbys when needed.
Amazon RDS Multi-AZ deployments with two readable standby database instances supports up to 2x faster transaction commit latencies than a Multi-AZ deployment with one standby instance. In this configuration, automated failovers typically take under 35 seconds. In addition, the two readable standbys can also serve read traffic.