elasticsearch/docs/reference/setup/important-settings/cluster-name.asciidoc

[[cluster-name]]
[discrete]
=== Cluster name setting

A node can only join a cluster when it shares its `cluster.name` with all the
other nodes in the cluster. The default name is `elasticsearch`, but you should
change it to an appropriate name that describes the purpose of the cluster.

[source,yaml]
--------------------------------------------------
cluster.name: logging-prod
--------------------------------------------------

IMPORTANT: Do not reuse the same cluster names in different environments.
Otherwise, nodes might join the wrong cluster.