Getting org.elasticsearch.transport.NodeDisconnectedException: [][inet[localhost/127.0.0.1:9300]][cluster/nodes/info] disconnected

Question

I am New in Elastic Search Java Api[5.0]. I am Using elasticsearch-5.0.0. I am try to create a Java Application(Maven) with Spring Boot. After run Application, it shows

2016-11-04 23:32:19.339  INFO 8280 --- [][generic][T#2]]      org.elasticsearch.client.transport       : [X-Ray] failed to get node info for [#transport#-1][DESKTOP-8SIPHSN][inet[localhost/127.0.0.1:9300]], disconnecting...
org.elasticsearch.transport.NodeDisconnectedException: [][inet[localhost/127.0.0.1:9300]][cluster:monitor/nodes/info] disconnected 

My Config File Is

@Configuration
public class ElasticsearchConfiguration {

  @Bean
  public Client client() {

        TransportClient client = new TransportClient();
        TransportAddress address = new  InetSocketTransportAddress("localhost",9300);
        client.addTransportAddress(address);        
        return client;
    }

}

And I am using default cluster "elasticsearch". I need help to solve my issue with proper detection of causes.

Answer 1

Try using the PreBuiltTransportClient mentioned in the 5.0 documentation:

TransportClient client = new PreBuiltTransportClient(Settings.EMPTY)
        .addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));

https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/transport-client.html

Also note that the TransportClient for ES version 2.x isn't compatible with 5.x:

The client must have the same major version (eg 2.x, or 5.x) as the nodes in the cluster. Clients may connect to clusters which have a different minor version (eg 2.3.x) but it is possible that new functionality may not be supported. Ideally, the client should have the same version as the cluster.

https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/client.html

Update

As a connectivity test, try executing the following simple program:

import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.transport.client.PreBuiltTransportClient;

import java.net.InetAddress;
import java.net.UnknownHostException;

public class App {
    public static void main(String[] args) throws UnknownHostException {
        // The following settings aren't strictly necessary, because the default cluster name is "elasticsearch".
        Settings settings = Settings.builder().put("cluster.name", "elasticsearch").build();
        TransportClient client = new PreBuiltTransportClient(settings);
        client.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName("localhost"), 9300));
        System.out.println(client.connectedNodes());
    }
}

It should print to stdout something like the following line:

[{luhcORJ}{luhcORJOSzSLPBeXocDsuQ}{mkTJpwIAQGuNYTHfRLqUIw}{127.0.0.1}{127.0.0.1:9300}]