Below are some pointers for your MOP.

1. Check and ensure that both appliances are running on the same version of the Appliance Management software.
2. Check that both appliance has more than 20% disk space available. 
3. Ensure that backups have been successful and if this is a virtual image you can take snap shots.
4. On the Primary Management Node login to the Appliance Maintenance Page and access to the High Availability Status Page and ensure that the database state is showing SYNCHRONIZED.
5.  Click on Swap High Availability Roles to change the role of the appliance from Active to Passive. The database state will change to SYNCHRONIZING and once the switch is completed the database state will show SYNCHRONIZED.
6. You can then perform any activity on the web console to test if the failover is successful. Run the Analytics and Reporting configuration wizard again to ensure that Analytics and Reporting is now working on the new Primary appliance/node.

Review below Technical Documentation for our High Availability. 

Business continuity