There was some unanswered questions about the difference between "Windows Server Failover Clustering" and "Always On Failover Cluster Instance".
From MS document:
A Windows Server Failover Clustering (WSFC) cluster is a group of independent servers that work together to increase the availability of applications and services. SQL Server 2017 takes advantage of WSFC services and capabilities to support Always On availability groups and SQL Server Failover Cluster Instances.
So we have 3 terms
Windows Server Failover Clustering
Always On availability groups
SQL Server Failover Cluster Instances
Does that mean i have to combine 1 with 2 or 3? Or i can only use 1 only?
Because in my case (2 EC2 instance with SQL Server 2016 Standard), here's what i did
On first EC2, i installed Failover Clustering Manager role from Server Manager
Then i created cluster and add nodes
I did some other configurations including DNS, network, witness
Now when one node go off (by stop EC2), the other node go online
In SQL Management, i just configured Merge Replication between 2 SQL Server insides 2 EC2
In this case, i used only WSFC? The reason why i asked is because in FCI document, it stated:
Storage Contrary to the availability group, an FCI must use shared storage between all nodes of the FCI for database and log storage. The shared storage can be in the form of WSFC cluster disks, disks on a SAN, Storage Spaces Direct (S2D), or file shares on an SMB. This way, all nodes in the FCI have the same view of instance data whenever a failover occurs. This does mean, however, that the shared storage has the potential of being the single point of failure, and FCI depends on the underlying storage solution to ensure data protection.
But i noticed that i didn't have any shared storage.
@The "Are “Always On Failover Cluster Instances” and “SQL Server Failover Clustering” the same thing?" didn't explain it.