SQL Server AlwaysOn Availability Groups (AGs) are the standard high-availability solution for enterprise workloads running on Amazon Elastic Compute Cloud (Amazon EC2). Configured correctly, they provide automatic failover, readable secondaries, and near-zero data loss, which is why many teams migrating SQL Server to AWS rely on them.
Secondaries can fall out of sync for several operational reasons: routine patching, network blips between Availability Zones, storage maintenance, or configuration changes on the replica. When that happens, a secondary replica might end up in SUSPENDED or NOT SYNCHRONIZING state. The traditional fix is to manually back up the primary, ship backups to the secondary, restore with NORECOVERY, and rejoin. This works, but it is slow, manual, and error-prone for large databases. Automatic seeding removes the manual steps but streams data over the wire, adding load to the primary during recovery.
In this post, we walk you through how to…
