Elastic Stack 9 : Elasticsearch Cluster2025/08/08

Configure Elasticsearch Cluster.

This example shows to configure Elasticsearch Cluster with 3 Nodes and configure each Node is Master Eligible Node and Data Node (default).

Each node serves one or more purpose, refer to details below.

⇒ https://www.elastic.co/guide/en/elasticsearch/reference/current/modules-node.html

[1]

Install and Run Elasticsearch on all Nodes. (installation only, do not start)

[2]

On the 1st node, start Elasticsearch and generate an enrollment token for other nodes.

[root@node01 ~]#

vi /etc/elasticsearch/elasticsearch.yml

# line 17 : uncomment and change (any name you like)

cluster.name:

elastic-cluster

# line 56 : uncomment and change (listen all)

network.host:

0.0.0.0

[root@node01 ~]#

systemctl enable --now elasticsearch

[root@node01 ~]#

/usr/share/elasticsearch/bin/elasticsearch-create-enrollment-token -s node

eyJ2ZXIiOiI4LjE0LjAiLCJhZHIiOlsiMTAuMC4wLjMwOjkyMDAiXSwiZmdyIjoiNzllNzA3YjZiNzEwOWJlNTNiNzQ1NzNiNTE0NzM2NTNhOTViNjg5OTI3NmM2NzMxYTdkOGIwY2VhNjFlZmUwNSIsImtleSI6Ikt3SHFocGdCelNkTWZxdjdGdW9kOmpxYVdQSjhjMTBxSzBYemV0b1hYVlEifQ==

[3]	If Firewalld is running, allow service ports on all Nodes.

[root@node01 ~]#

firewall-cmd --add-port={9200/tcp,9300/tcp}

success
[root@node01 ~]#

firewall-cmd --runtime-to-permanent

success

[4]	On other nodes, join in cluster with an enrollment token generated on the 1st node above.

[root@node02 ~]# /usr/share/elasticsearch/bin/elasticsearch-reconfigure-node --enrollment-token \
eyJ2ZXIiOiI4LjE0LjAiLCJhZHIiOlsiMTAuMC4wLjMwOjkyMDAiXSwiZmdyIjoiNzllNzA3YjZiNzEwOWJlNTNiNzQ1NzNiNTE0NzM2NTNhOTViNjg5OTI3NmM2NzMxYTdkOGIwY2VhNjFlZmUwNSIsImtleSI6Ikt3SHFocGdCelNkTWZxdjdGdW9kOmpxYVdQSjhjMTBxSzBYemV0b1hYVlEifQ==
This node will be reconfigured to join an existing cluster, using the enrollment token that you provided.
This operation will overwrite the existing configuration. Specifically:
  - Security auto configuration will be removed from elasticsearch.yml
  - The [certs] config directory will be removed
  - Security auto configuration related secure settings will be removed from the elasticsearch.keystore
Do you want to continue with the reconfiguration process [y/N]y

[root@node02 ~]#

vi /etc/elasticsearch/elasticsearch.yml

# line 17 : uncomment and specify the same name with 1st node

cluster.name:

elastic-cluster

# line 56 : uncomment and change (listen all)

network.host:

0.0.0.0

[root@node02 ~]#

systemctl enable --now elasticsearch

[5]	Verify Cluster status. If the status is green, That's OK.

[root@node01 ~]#

curl -u elastic --cacert /etc/elasticsearch/certs/http_ca.crt https://node01.srv.world:9200/_cat/nodes?v

Enter host password for user 'elastic':
ip        heap.percent ram.percent cpu load_1m load_5m load_15m node.role   master name
10.0.0.51           15          95   3    0.00    0.08     0.07 cdfhilmrstw *      node01.srv.world
10.0.0.52           38          97   5    0.08    0.15     0.08 cdfhilmrstw -      node02.srv.world
10.0.0.53           35          97  28    0.74    0.29     0.10 cdfhilmrstw -      node03.srv.world

[root@node01 ~]#

curl -u elastic --cacert /etc/elasticsearch/certs/http_ca.crt https://node01.srv.world:9200/_cluster/health?pretty

Enter host password for user 'elastic':
{
  "cluster_name" : "elastic-cluster",
  "status" : "green",
  "timed_out" : false,
  "number_of_nodes" : 3,
  "number_of_data_nodes" : 3,
  "active_primary_shards" : 3,
  "active_shards" : 6,
  "relocating_shards" : 0,
  "initializing_shards" : 0,
  "unassigned_shards" : 0,
  "unassigned_primary_shards" : 0,
  "delayed_unassigned_shards" : 0,
  "number_of_pending_tasks" : 0,
  "number_of_in_flight_fetch" : 0,
  "task_max_waiting_in_queue_millis" : 0,
  "active_shards_percent_as_number" : 100.0
}

Matched Content