Elasticsearch:Transport Client (5.x)

Prerequisites

Before you begin, make sure that you have:

• JDK 1.8 or later installed. See Install a JDK

• An Alibaba Cloud Elasticsearch V5.5.3 cluster. See Create an Alibaba Cloud Elasticsearch cluster

• Auto Indexing enabled for the cluster. See Configure the YML file

Configure network access

Choose your connection method based on where your Java client runs.

Internet (public endpoint)

If your Java client is outside a virtual private cloud (VPC):

1. Enable Public Network Access for your cluster.

2. Add your client's public IP address to the cluster's public IP address whitelist. See Configure a public or private IP address whitelist for an Elasticsearch cluster.

Same VPC (internal endpoint)

If your Java client runs in the same VPC as the Elasticsearch cluster, use the cluster's internal endpoint. The private IP whitelist defaults to 0.0.0.0/0.

Add POM dependencies

Add the following dependencies to your pom.xml:

<repositories>
    <!-- Elasticsearch Maven repository -->
    <repository>
        <id>elasticsearch-releases</id>
        <url>https://artifacts.elastic.co/maven</url>
        <releases>
            <enabled>true</enabled>
        </releases>
        <snapshots>
            <enabled>false</enabled>
        </snapshots>
    </repository>
</repositories>
<dependencies>
    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>x-pack-transport</artifactId>
        <version>5.3.3</version>
    </dependency>
    <dependency>
        <groupId>org.elasticsearch</groupId>
        <artifactId>elasticsearch</artifactId>
        <version>5.3.3</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-api</artifactId>
        <version>2.7.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>2.7.1</version>
    </dependency>
</dependencies>

Connect to the cluster

The following code shows how to initialize a Transport Client connection. Replace the placeholders with your actual cluster values.

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

import java.net.InetAddress;

// Initialize the Transport Client
TransportClient client = new PreBuiltXPackTransportClient(Settings.builder()
        .put("cluster.name", "<cluster-id>")                        // Your cluster ID
        .put("xpack.security.user", "elastic:<password>")          // Username and password
        .put("client.transport.sniff", false)                      // Must be false
        .build())
        .addTransportAddress(new InetSocketTransportAddress(
                InetAddress.getByName("<endpoint>"), 9300));        // Endpoint (no http://) and port

// Close the client when done
client.close();

Replace the following placeholders:

Example

The following example connects to the cluster, writes a document to an index, and retrieves it. Download the complete sample code.

import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.InetSocketTransportAddress;
import org.elasticsearch.xpack.client.PreBuiltXPackTransportClient;

import static org.elasticsearch.common.xcontent.XContentFactory.*;

import java.net.InetAddress;

public class TransportClientDemo {

    public static void main(String[] args) {
        try {
            // Initialize the client
            TransportClient client = new PreBuiltXPackTransportClient(Settings.builder()
                    .put("cluster.name", "es-cn-n6w1rux8i000w****")
                    .put("xpack.security.user", "elastic:es_password")
                    .put("client.transport.sniff", false)
                    .build())
                    .addTransportAddress(new InetSocketTransportAddress(
                            InetAddress.getByName("es-cn-n6w1rux8i000w****.public.elasticsearch.aliyuncs.com"), 9300));

            // Write a document to the index
            IndexResponse idxResp3 = client.prepareIndex("test_index", "test_type", "333")
                    .setSource(jsonBuilder()
                            .startObject()
                            .field("user_id", "333")
                            .field("email", "a***@aliyun.com")
                            .endObject()
                    )
                    .get();
            System.out.println(idxResp3.toString());

            // Retrieve the document
            GetResponse getResp = client.prepareGet()
                    .setIndex("test_index")
                    .setType("test_type")
                    .setId("333")
                    .execute()
                    .get();
            System.out.println(getResp.getSourceAsString());

            client.close();

        } catch (Exception e) {
            System.out.println(e);
        }
    }
}

Troubleshooting

`NoNodeAvailableException`

This error occurs when you use Transport Client 5.5 or 5.6 to connect to an Elasticsearch V5.x cluster. Use Transport Client 5.3.3 instead.

`Timeout connecting`

The cluster cannot be reached. Check that:

• Your client's IP address is in the cluster's whitelist (public or private, depending on your network)

• You are using the correct endpoint (public vs. internal) for your network environment

• The whitelist entry uses the Internet egress IP, not the private IP, for home or office LAN clients

Auto Indexing error on document write

If an error appears when writing a document, Auto Indexing may be disabled. Enable it in the cluster's YML configuration. See Configure the YML file.

What's next

• Java Low Level REST Client — the recommended client for new projects, with full version compatibility

• View the basic information of a cluster

• Reset the access password for an Elasticsearch cluster