SpringData Elasticsearch NoNodeAvailableException - elasticsearch

Question

I am using SpringData to connect my application to Elastic search local instance. When I do a regular curl to get ES info, it works fine, but I am unable to connect to it from Springboot application.
Elasticsearch local version ./elasticsearch -V => Version: 7.6.0
SpringData Elastic search version 3.1.11
> curl -XGET 'http://localhost:9200/_cluster/state?pretty'
{
"cluster_name" : "elasticsearch",
"cluster_uuid" : "1_8HMIK5QDug_xH80VZLgQ",
"version" : 54,
"state_uuid" : "YEe1FSwfRUuw0uw-T69fJQ",
"master_node" : "Nbktx7KrREetbyfL7v0Fog",
"blocks" : { },
"nodes" : {
"Nbktx7KrREetbyfL7v0Fog" : {
"name" : "k***-macOS",
"ephemeral_id" : "pqMw40oPTUmBoHsyTAz9cg",
"transport_address" : "127.0.0.1:9301",
"attributes" : {
"ml.machine_memory" : "17179869184",
"xpack.installed" : "true",
"ml.max_open_jobs" : "20"
}
}
},
#Value("$ELASTIC_HOST")
private String EsHost;
#Value("$ELASTIC_PORT")
private String EsPort;
#Bean
public ElasticsearchOperations elasticsearchTemplate() throws UnknownHostException {
return new ElasticsearchTemplate(elasticsearchClient());
}
#Bean
public Client elasticsearchClient() throws UnknownHostException {
Settings settings = Settings.builder()
.put("client.transport.sniff", true).build();
TransportClient client = new PreBuiltTransportClient(settings);
client.addTransportAddress( new TransportAddress(InetAddress.getByName(EsHost), Integer.valueOf(EsPort));
return client;
}
Tried all the above ways to get a host and port ALSO TRIED WITH 9300 but still no luck. Also, my elasticsearch.yml is the default file and did not add any explicit host or ports.
Docker-compose
version: '3'
services:
elastic:
restart: always
image: docker.elastic.co/elasticsearch/elasticsearch:6.2.2
environment:
- cluster.name=elasticsearch
- node.name=es01
- discovery.type=single-node
- "ES_JAVA_OPTS=-Xms512m -Xmx512m"
ulimits:
memlock:
soft: -1
hard: -1
ports:
- "9201:9200"
- "9301:9300"
db:
restart: always
image: postgres
ports:
- "5432:5432"
environment:
POSTGRES_PASSWORD: 'xxx'
POSTGRES_USER: 'xx'
POSTGRES_DB: 'xx'
api:
build:
context: .
dockerfile: Dockerfile
ports:
- "8080:8080"
environment:
ENVIRONMENT_NAME: "dev"
REGION_NAME: "local"
POSTGRES_PASSWORD: "xx"
POSTGRES_USER: "xx"
POSTGRES_HOST: "db"
ELASTIC_HOST: "elastic"
ELASTIC_PORT: "9200"
depends_on:
- db
- elastic
ERROR:
"failed to load elasticsearch nodes : org.elasticsearch.client.transport.NoNodeAvailableException: None of the configured nodes are available: [{#transport#-1}{JjFZc4y-RBCYbdELAsgaAQ}{elastic}{172.20.0.2:9200}]"}
It works if I change this to
environment:
ENVIRONMENT_NAME: "dev"
REGION_NAME: "local"
POSTGRES_PASSWORD: "xxx"
POSTGRES_USER: "xx"
POSTGRES_HOST: "db"
ELASTIC_HOST: "elastic"
ELASTIC_PORT: "9300" --> this is changed from 9200
client.addTransportAddress(new TransportAddress(InetAddress.getLocalHost(), 9201));
No, idea why !!

Answer 1

Spring Data Elasticsearch 3.1.11 is built with Elasticsearch client libraries in version 6.2.2. So even if you manage to get a connection to the cluster, the chances are very high, that the client and the cluster can't communicate properly.
As for the setup of the connection: You should add the name of the cluster you want to connect to into the settings:
Settings settings = Settings.builder()
.put("client.transport.sniff", true)
.put("cluster.name", "elasticsearch")
.build();