MSSQL AlwaysOn MFSP

Be careful of breaching the "Maximum failures in the specified period" (MFSP). For example, if the MFSP is set to 3 and the period is set to 6 then more than 3 "failures" will prevent automatic failover from happening. 

The following are seen as "failures" (1)

• Stopping/Restarting the SQL Server Engine Service.

• A server reboot.

• The automatically executed sp_server_diagnostics stored procedure when it encounters server errors or unresponsiveness.

Use the Failover Cluster Manager tool to check/change the values for MFSP and Period.