Elasticsearch Cluster - no node visible

[zicherka]

Hi
System: CentOS 8 Stream
Elasticsearch ver: 8.1.0
Nodes:

node1.test.com 192.168.100.101
node2.test.com 192.168.100.102
node3.test.com 192.168.100.103

All nodes can be pinged by IP and FQDN, Firewalld has open ports 9200 / tcp, 9300 / tcp on all hosts.
Config:

/etc/elasticsearch/elasticsearch.yml

cluster.name: elastic-cluster
node.name: ${HOSTNAME}
path.data: /var/lib/elasticsearch
path.logs: /var/log/elasticsearch
network.host: 0.0.0.0
http.port: 9200
discovery.seed_hosts: ["node1.test.com", "node2.test.com", "node3.test.com"]
cluster.initial_master_nodes: ["node1.test.com", "node2.test.com", "node3.test.com"]

After configuring the elasticsearch.yml file (the same on each host), the following was done:
# systemctl enable --now elasticsearch

Command:
# curl http://192.168.100.101:9200/_cat/nodes?v
returns:

ip heap.percent ram.percent cpu load_1m load_5m load_15m node.role master name
192.168.100.101 15 95 54 0.01 0.59 1.20 cdfhilmrstw * node1.test.com

Does not show the remaining 2 nodes

Command:
# curl http://192.168.100.101:9200/_cluster/health?pretty
Returns:

{
"cluster_name": "elastic-cluster",
"status": "green",
"timed_out": false,
"number_of_nodes": 1, (and should be 3)
"number_of_data_nodes": 1, (and should be 3)
"active_primary_shards": 3,
"active_shards": 3,
"relocating_shards": 0,
"initializing_shards": 0,
"unassigned_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
}

Can you ask for help in solving the problem? The system (on all nodes) was installed from scratch in one of the attempts, and only elasticsearch was installed on it.

[zicherka]

The solution is very easy!
Turn off all nodes that are part of the cluster.
Then delete all data (files, directories) from the location specified in [Elasticsearch.yml] as [path.data =].
In my case, these are respectively:
[/etc/Elasticsearch/Elasticsearch.yml]
path.data = / var / lib / Elasticsearch
Then we restart individual cluster nodes.
In my case, that solved the problem.
Greetings