I am ready to add some nodes to my 1 node cluster. But to do so, I have to add the list of hosts to my discovery.zen.ping.unicast.hosts array. It is in the configuration file, that means I have to restart my node?
In the future, If I want to add some extra nodes, how can I do this without changing this discovery.zen.ping.unicast.hosts property (and therefore restart my nodes)?
In theory you only need to identify one discovery host (node) for a new node to be able to join the cluster, but since that node may be down it's better to add several discovery nodes.
In the clusters I work with, where I use the minimum of 3 master eligible nodes, I always identify those 3 nodes in **discovery.zen.ping.unicast.hosts** but never any of the data nodes, since I will probably never have to add more master eligible nodes while I may continue to add data nodes to expand cluster capacity.
So once you've grown your cluster big enough to warrant a fixed number of master eligible nodes just add those nodes to your discovery settings and never change it again.