I'm reading some windows docs about AOAG and I got confused:

Always On availability groups, the high availability and disaster recovery solution introduced in SQL Server 2012 (11.x), requires Windows Server Failover Clustering (WSFC). Also, though Always On availability groups is not dependent upon SQL Server Failover Clustering, you can use a failover clustering instance (FCI) to host an availability replica for an availability group. It is important to know the role of each clustering technology, and to know what considerations are necessary as you design your Always On availability groups environment.

And then:

Windows Server Failover Clustering and Availability Groups Deploying Always On availability groups requires a Windows Server Failover Cluster (WSFC). To be enabled for Always On availability groups, an instance of SQL Server must reside on a WSFC node, and the WSFC and node must be online.

I've never heard about aoag without windows failover cluster.

is it possible to have AOAG on just 2 machines not part oa windows clustering?

1 Answer 1


is it possible to have AOAG on just 2 machines not part oa windows clustering?

Yes. They are available in SQL Server 2017 and later, but not for HA, only for "read scale" and disaster recovery. For High Availability the AG needs a cluster to provide quorum and heartbeat detection to support automatic failover.

Read-scale availability groups without cluster

In SQL Server 2016 (13.x) and earlier, all availability groups required a cluster. The cluster provided business continuity for high availability and disaster recovery (HADR). In addition, secondary replicas were configured for read operations. If high availability wasn't the goal, considerable operational overhead was expended to configure and operate a cluster. SQL Server 2017 introduces read-scale availability groups without a cluster.

Use read-scale with Always On availability groups

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