Aurora PostgreSQL versions 16.6, 15.10, 14.15, 13.18, 12.22, or higher contain availability improvements that enable secondary Region read replicas to maintain service continuity during unplanned events such as hardware failures, network disruptions across AWS Regions, large volumes of data transfers between the clusters, and others.
Although the read replicas remain available for your application requests, the replication lag may continue to
increase until the resolution of the unplanned event. You can monitor the lag between primary and secondary
clusters using the AuroraGlobalDBProgressLag CloudWatch metric. To measure the end-to-end lag, including
any lag between the cluster volume and DB instances of the secondary cluster, add the values of the
AuroraGlobalDBProgressLag and AuroraReplicaLag CloudWatch metrics. For more information
about metrics, refer to Metrics reference for Amazon Aurora.
The Global Database read availability for Aurora MySQL and earlier versions of Aurora PostgreSQL may be impacted during such unplanned events.
For more information about new features in Aurora PostgreSQL 16.6, 15.10, 14.15, 13.18, and 12.22, see PostgreSQL 16.6 in the Aurora PostgreSQL Release Notes.
