RE: https://msdn.microsoft.com/en-us/library/ff878487(v=sql.110).aspx#DotNetHotfixes
Personally I Struggle with A WSFC node can host only one availability replica for a given availability group =one or more instances of SQL Server can host availability replicas for many availability gr oupsand ive been unable to locate a decent online explanation of this Statement.
Ensure that the WSFC cluster contains sufficient nodes to support your availability group configurations. | A WSFC node can host only one availability replica for a given availability group. On a given WSFC node, one or more instances of SQL Server can host availability replicas for many availability groups. Ask your database administrators how many WSFC nodes are required for to support the availability replicas of the planned availability groups. |
My client wants to Install 3 SQL Instances on a two node Syncronous mode cluster with 1 AG in Each SQL Instance , Ie three sql instances on Each Node and has been told this is supported I struggle with the Failover being at node Level and the above statement. ie If 1 AG Group Fails over the physical node what state are my other 2 instances in? How Do I nswer the above question "how many WSFC nodes are required for to support the availability replicas of the planned availability groups." ?
Regards