node.name

By default, Elasticsearch will use the first seven characters of the randomly generated UUID as the node id. Note that the node id is persisted and does not change when a node restarts and therefore the default node name will also not change.

It is worth configuring a more meaningful name which will also have the advantage of persisting after restarting the node:

node.name: prod-data-2

The node.name can also be set to the server’s HOSTNAME as follows:

node.name: ${HOSTNAME}