Horizon Dashboard and OpenStack api(s) start failing with 503 Service Unavailable if the provisioning network connectivity fails on any controller in a 3 controller HA environment

Issue

• The provisioning network is experiencing connection issues on a single controller
• Horizon and OpenStack api(s) are failing to retrieve information if the provisioning network connectivity fails on any controller in a 3 controller HA environment
• The controller node is not getting fenced even after provisioning network disconnect