For production environment, Nirmata should be deployed in HA configuration. For HA setup, 6 VMs (nodes) are required – 3 for shared services and 3 for core services.
Note: Some distributed services, like Zookeeper, require an odd number of nodes to form a quorum and hence a 2-node configuration is not supported.
To ensure resiliency against cloud/datacenter outage, the nodes should be deployed in at least 2 different availability zones (preferably 3 different availability zones). Every node needs access to every other node via a routable IP address or domain name (L3).
The diagram below shows the details of the setup: