Transition a Standby Server to Active Mode

Manually verify that the main database really is down (as opposed to a connectivity issue for a particular app server). Make sure it will not come back online later.
Determine if the main database’s host machine is down and cannot be restarted.
If the main database’s host machine is up, log into it and check if the demisto service is down and cannot be restarted.
If the demisto service is up, rule out a network or firewall issue by checking if the main database’s machine is accessible from the app server's machine.
For each app server:
Stop the service.
- CentOS:
sudo systemctl stop demisto
- Ubuntu:
sudo service demisto stop
Manually change the active database address in the server's local configuration file. The default location of the configuration file is
/etc/demisto.conf
For example:

Start the service.
- CentOS:
sudo systemctl start demisto
- Ubuntu:
sudo service demisto start
Navigate to the URL of the passive server and log in as an administrator. You are presented with the following page:

Click the
Make this the production server
button.
In the Switch Hosts dialog window, type
Switch Hosts
in the text box.