Major Version Upgrades in Aurora Cluster With Replicas - Can it be done in batches ?

Question

For Major version upgrades in Aurora cluster, AWS documentation says: 
"*To safely upgrade your DB instances, Aurora PostgreSQL uses the pg_upgrade utility described in the PostgreSQL documentation. After the writer upgrade completes, **each reader instance experiences a brief outage** while it's upgraded to the new major version automatically*."

Document link: https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/USER_UpgradeDBInstance.PostgreSQL.html

If the cluster has 10 replicas is it possible to do the upgrade in batches or one-by-one, so that the clients dependent on the replicas do not experience downtime ?

Accepted Answer

Unfortunately, no. Aurora manages all the nodes at the cluster level and data replication synchronously across Availability zones, hence it does not provide an option to choose upgrading specific nodes separately. The application will have to be stopped, and once the cluster is entirely upgraded, you can resume the application.

Major Version Upgrades in Aurora Cluster With Replicas - Can it be done in batches ?

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