Before adding nodes, it is very important that we create a full backup of the database, as adding nodes in Vertica is a sensitive process. To add a new node, we will be using the update_vertica script. However, before adding a node to an existing cluster, the following are certain restrictions and prerequisites that have to be kept in mind:
Make sure that the database is running.
Newly added nodes should be reachable by all the existing nodes in the cluster.
If we have a single node cluster that is deployed, without specifying the IP address, hostname, or hostname specified as the local host, it is not possible to expand the cluster. We must reinstall Vertica and specify an IP address or hostname.
Generally, it is not needed to shut down the Vertica database for expansion, but a shutdown is necessary if we are expanding it from a single node cluster.