Availability databases in unhealthy data synchronization state

The AlwaysOn user database showed not healthy data synchronization state

Database on AG group showed “Not Synchronizing”

And the warnings message “Data synchronization state of some availability database is not healthy”

In the SQL Server Management Studio for Secondary availability group replicas showed below:

I did some research and found MSDN article posted:

https://docs.microsoft.com/en-us/sql/database-engine/availability-groups/windows/data-synchronization-state-of-some-availability-database-is-not-healthy?view=sql-server-2017

• The availability replica might be disconnected
• The data movement might be suspended
• The database might not be accessible
• There might be a temporary delay issue due to network latency or the load on the primary or secondary replica

Solution

Execute the following  T-SQL statement on primary and all secondary replica for the databases that showed “Not Synchronizing” status.

ALTER DATABASE  [DB_Test] SET HADR RESUME