What is multi subnet AlwaysOn availability group?
A SQL Server multi-subnet failover cluster is a configuration where each failover cluster node is connected to a different subnet or different set of subnets. These subnets can be in the same location or in geographically dispersed sites.
What is preferred owner in cluster?
When a failover occurs, the cluster software uses the preferred owner nodes list to determine the node to which it must fail over the group. The cluster software fails over the group to the top-most node in the list that is up and running and is a possible owner node for the group.
Are there any issues with multi subnet failover cluster availability groups?
To be honest we have had a number of unexpected issues with using Multi-Subnet Failover Cluster Availability Groups, and it seems like the default preferred role owners and possible resource owners may be incorrect or at least not optimal for our scenario.
What does it mean to have preferred owners in cluster?
The key point I want to make is that, when you set the preferred owners for a group to a subset of the nodes in a cluster, you’re not saying “I want the group to failover only to these nodes”. What you’re effectively saying is, “please reorder the nodes such that these are at the front of the list.”
Which is the priority for the availability group?
The priority is first for current primary replica. This is only for the availability group resource and not for other resources. For example, dependent resources like listener, listener IP have all availability group failover nodes as possible owners.
How are clustered resources managed in SQL Server?
As a clustered resource, the availability group clustered resource/role have configurable cluster properties, like possible owners and preferred owners. SQL Server actively manages these resource properties. These properties are set automatically by SQL Server and should not be modified using Failover Cluster Manager.