Function of SQL Server always-on high availability group database has been released for 10+ years. But in the market, I only see one product can monitor the backups for always-on databases based on AG, others are all based on SQL Instances.
Here is the details.
In AAG environment, backup was configured to been taken from only one SQL instance (normally taken from the instance holding the primary replica). Customers don't care from which SQL instance the backup was taken, as long as a backup was taken.
DPA offers metrics/alerts to monitor the backups based on monitored connections (normally they are connections to SQL instances). DPA checks all SQL instances for the backups that have not been taken for last X number of days and send alerts. By using these metrics/alerts, we received many false alerts, because backups are only taken from an instance that holding the primary database replica.
My suggestion is adding a function in DPA, to monitor the backups based on AG group if the databases under monitoring are part of AGs
