When a Skype for Business Server 2015 backend SQL server is using database mirroring for high availability, some information on issues with the mirroring relation is required.
Set up Database Mirroring Monitor:
Launch the Database Mirroring Monitor tool
Go to Menu -> Action and select Register Mirrored Database
Select the primary server in the drop down menu and tick all the databases you want to monitor
Select a database and go to Warnings pane, click Set Thresholds
Set thresholds like this
Repeat for every database mirror relation you want to monitor
Now you will get an informational event 32042 in the application event log when the size of unsent transaction exceeds 100KB
And you will recieve an informational event 32040 in the application event log when the age of the oldest unsent transaction surpasses 5 minutes (4 minutes on mirror server)
Now you will add the event log entries to your favorite monitoring tool and you should be covered from this event, if you react properly to these above event
Which occurs when the transaction log is full due to database mirroring stopped.
Set up Database Mirroring Monitor:
Launch the Database Mirroring Monitor tool
Go to Menu -> Action and select Register Mirrored Database
Select the primary server in the drop down menu and tick all the databases you want to monitor
Select a database and go to Warnings pane, click Set Thresholds
Set thresholds like this
Repeat for every database mirror relation you want to monitor
Now you will get an informational event 32042 in the application event log when the size of unsent transaction exceeds 100KB
And you will recieve an informational event 32040 in the application event log when the age of the oldest unsent transaction surpasses 5 minutes (4 minutes on mirror server)
Now you will add the event log entries to your favorite monitoring tool and you should be covered from this event, if you react properly to these above event
Which occurs when the transaction log is full due to database mirroring stopped.