Sql-server – AlwaysOn AG: Current Host Server – Owner Node – Primary Instance

availability-groupsclusteringsql server

I'm building up a SQL Server AlwaysOn AG and I'm on the step "failover", manual and automatic:

I noticed that in the Windows Server Failover Cluster a "Current Host Server" exists. My knowledge says that this is the "master" of the cluster that the cluster hosts. But now I noticed that the "Owner Node", which hosts the Availability Group(-role) a other node could be. (The owner node is also the primary instance of the AG, right?)

Now for me there exist two questions for the normal operating of an AlwaysOn AG:

Q1: Should the "Current Host Server" the same as the Owner Node of the AlwaysOn AG?

Q2: Imagine if I want to maintain a host. Shall I first failover the AG (via SSMS or with ALTER AVAILABILITY GROUP…) to the second node/another node and at second a failover of the WSFC-Current Host?

Maybe someone could help me with this questions and give me some advice.

Thanks

Best Answer

Should the "Current Host Server" the same as the Owner Node of the AlwaysOn AG?

That's the node that is currently hosting the core cluster resources, it isn't the same and is just another role. Different roles can be owned by different nodes. In this case, they do not need to be the same - and generally most people don't care who owns the core cluster resources in a WSFC that only has SQL Server. It does make a difference in certain situations but for the vast majority, it makes no real difference.

Imagine if I want to maintain a host. Shall I first failover the AG (via SSMS or with ALTER AVAILABILITY GROUP...) to the second node/another node and at second a failover of the WSFC-Current Host?

If you're going to be maintenance to a host, I'd move all roles (drain) off of that node. So, yes, everything should be moved from it.

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