In my environment we have 1 Primary 1 Synchornous Secondary and 1 Asynchronous Secondary Replica (Off site). We are planning to do a manual failover to the Asynchronous Secondary Replica (Off site) as the Primary data center will be down due to maintenance.
My question is will there be any problem if I manually change the Availability Mode to Synchronous mode from Asynchronous mode and do the failover
Best Answer
No. It is not a problem.
Just to it in a low intensive moment. And waith sync is complete. You can check it via interface.
Otherwise you can use this query (checked in SQL 2016):
synchronization_state_desc must be: SYNCHRONIZED.
Then you can switch.