How to backup and restore OpenStack

Issue

• I would like to take regular backup of database, configuration files and other details from all OpenStack controller nodes (keystone, glance, Neutron and etc) and use them to restore when one of them crashes beyond recovery. What is the procedure to Backup and Restore?
• What is the OpenStack backup strategy for instances (VMs) on this platform?
• For disaster recovery purpose, I will be able to backup and restore entire OpenStack database. What is the right procedure to backup and restore MariaDB database while running highly available with Galera?