SQL Server Error Log (AlwaysOn Availability Groups)
The SQL Server Error Log reports events affecting AlwaysOn Availability Groups, such as:
Communication with the Windows Server Failover Clustering (WSFC) cluster
State transitions of availability replicas
State transitions of availability databases
Connectivity state of availability databases between primary and secondary replicas
Statuses of the availability group endpoints
Statuses of the availability group listeners
Lease status between the SQL Server resource DLL (running in the WSFC cluster) and the SQL Server instance (for more information, see How It Works: SQL Server AlwaysOn Lease Timeout)
Error events in the availability group
The following symptoms should lead to review of the SQL Server Error Log:
Cannot access availability databases
Unexpected availability group failover
Availability group is in the Resolving state unexpectedly
Availability group is in an indeterminate state
See Also
View the SQL Server Error Log (SQL Server Management Studio)