Hi,
Can you explain your question in more details and also specify which part of SQL Server Always On offering you are thinking of (Always On Failover Cluster Instances or Always On availability groups)?
Always On Failover Cluster Instances leverages Windows Server Failover Clustering (WSFC) functionality to provide local high availability through redundancy at the
server-instance level—a failover cluster instance (FCI). The FCI provides failover
from one WSFC node to another if the current node becomes unavailable. For more information, please refer to the documents from
Always On Failover Cluster Instances (SQL Server).
For an Always On availability group, it supports a replicated environment for a discrete set of user
databases. A high availability group is a group of databases that fail over together. There are three forms of failover exist in AG: automatic failover (without data loss), planned manual failover (without data loss), and forced manual failover
(with possible data loss), typically called forced failover. About how these three forms of failover work, please refer to the document from
Failover and Failover Modes (Always On Availability Groups).
Best Regards
Puzzle
MSDN Community Support
Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to
MSDN Support, feel free to contact MSDNFSF@microsoft.com
