Elasticsearch 5 Java Client giving "NoNodeAvailableException"

Question

I am using Elasticsearch 5.2 and Spring Boot 1.5.1. I am connecting to it via the Java client in a Spring app. When I connect to it on port 9300 or 9200 and I get NoNodeAvailableException: None of the configured nodes are available. In my Java client, I have set the client.transport.sniff property as true. On sending a request to it via cURL on port 9200, it is working correctly. I have 4 nodes in a single cluster and I cannot connect to any of them. My configuration file has all of the default values in the network division except for network.host which has eth0 inet addr as the value.

I am using Gradle. My dependencies are:

compile('org.springframework.boot:spring-boot-starter-web')
compile('org.elasticsearch:elasticsearch:5.2.0')
compile('org.elasticsearch.client:transport:5.2.0')
compile('org.apache.logging.log4j:log4j-api:2.7')
compile('org.apache.logging.log4j:log4j-core:2.7')

My code for connecting to the Elasticsearch cluster:

@Bean
public TransportClient elasticClient() {
    org.elasticsearch.common.settings.Settings settings = Settings.builder()
        .put("client.transport.sniff", true)
        .put("cluster.name", "TestCluster")
            .build();
    TransportClient client = null;
    try {
        client = new org.elasticsearch.transport.client.PreBuiltTransportClient(settings)
            .addTransportAddress(new org.elasticsearch.common.transport.InetSocketTransportAddress(
                InetAddress.getByName("54.175.155.56"), 9200));
    } catch (UnknownHostException e) {
        e.printStackTrace();
    }
    return client;
}

My ES logs when ES starts are:

[2017-02-15T10:37:40,664][INFO ][o.e.t.TransportService   ] [ip-10-0-29-2] publish_address {10.0.29.2:9300}, bound_addresses {10.0.29.2:9300}
[2017-02-15T10:37:40,669][INFO ][o.e.b.BootstrapChecks    ] [ip-10-0-29-2] bound or publishing to a non-loopback or non-link-local address, enforcing bootstrap checks
[2017-02-15T10:37:43,856][INFO ][o.e.c.s.ClusterService   ] [ip-10-0-29-2] detected_master {kafka-stage}{sTIeF8gGTNam0oNW8dkbbA}{TTX6FIRtRp-gDemYY-22Sg}{10.0.20.71}{10.0.20.71:9300}, added {{kafka-stage-2}{jl3oLGgMQ1yxhdMMy65k_g}{ibV8BApjRByUOpDDncddyQ}{10.0.51.31}{10.0.51.31:9300},{ip-10-0-40-144}{t-_THs3wQbC_k9eivDo5eQ}{v-UYoYgXQ265QkdYhtiPYA}{10.0.40.144}{10.0.40.144:9300},{kafka-stage}{sTIeF8gGTNam0oNW8dkbbA}{TTX6FIRtRp-gDemYY-22Sg}{10.0.20.71}{10.0.20.71:9300},}, reason: zen-disco-receive(from master [master {kafka-stage}{sTIeF8gGTNam0oNW8dkbbA}{TTX6FIRtRp-gDemYY-22Sg}{10.0.20.71}{10.0.20.71:9300} committed version [98]])
[2017-02-15T10:37:44,009][INFO ][o.e.h.HttpServer         ] [ip-10-0-29-2] publish_address {10.0.29.2:9200}, bound_addresses {10.0.29.2:9200}
[2017-02-15T10:37:44,009][INFO ][o.e.n.Node               ] [ip-10-0-29-2] started

The answers at these questions don't solve my problem:

1. Java ElasticSearch None of the configured nodes are available
2. Elasticsearch - NoNodeAvailableException
3. Elasticsearch NoNodeAvailableException issue

Answer 1

In your elasticsearch.yml configuration file you need to make sure to bind to the correct host and have the following setting:

network.host: 54.175.155.56

Also in your Java code, since you're using the transport client you need to use the port 9300 (for TCP communication) and not 9200, which is meant for HTTP communication (e.g. via curl)

    client = new org.elasticsearch.transport.client.PreBuiltTransportClient(settings)
        .addTransportAddress(new org.elasticsearch.common.transport.InetSocketTransportAddress(
            InetAddress.getByName("54.175.155.56"), 9300));
                                                     ^
                                                     |
                                                change this

Answer 2

The node to which I was connecting to was only a master node. It had node.ingest and node.data as false. On connecting to a node which had node.ingest as true and removing the client.transport.sniff setting in the Java client, I was able to connect to the ES cluster.

Answer 3

Most Probably the answer of this question is clustername may be different from the elasticsearch.yml, do configure that and in elasticsearch it uses two ports: they are 9200 which provides access through http and 9300 is used for accessing Elasticsearch through the internal transport protocol, which is used by Java Transport Client.