Dropwizard Elasticsearch 6

A set of classes for using Elasticsearch (version 6.2.3 and higher) in a Dropwizard application.

The package provides a lifecycle-managed client class (ManagedEsClient), a configuration class with the most common options (EsConfiguration), and some health checks which can instantly be used in any Dropwizard application.

Usage

Just add EsConfiguration to your Configuration class and create an ManagedEsClient instance in the run method of your service.

You can also add one of the existing health checks to your Environment in the same method. At least the usage of EsClusterHealthCheck is strongly advised.

public class DemoApplication extends Application<DemoConfiguration> {
    // [...]
    @Override
    public void run(DemoConfiguration config, Environment environment) {
        final ManagedEsClient managedClient = new ManagedEsClient(configuration.getEsConfiguration());
        environment.lifecycle().manage(managedClient);
        environment.healthChecks().register("ES cluster health", new EsClusterHealthCheck(managedClient.getClient()));
        // [...]
    }
}

Configuration

The following configuration settings are supported by EsConfiguration:

• transportClient: When true, ManagedEsClient will create a TransportClient, otherwise a RestClient; default: false
• servers: A list of servers for usage with the created client.
• clusterName: The name of the Elasticsearch cluster; default: "elasticsearch" (TransportClient only)
• settings: Any additional settings for Elasticsearch, see Configuration (TransportClient only)
• settingsFile: Any additional settings file for Elasticsearch, see Configuration (TransportClient only)
• headers: Any additional headers that should be sent (RestClient only)
• sniffer: Sniffer configuration (RestClient only)
  • enabled: Should the Sniffer be enabled; default: false
  • snifferIntervalMillis: Interval between sniffer checks; default 600000
  • sniffOnFailure: Should the sniffer use a failure listener; default false
  • sniffFailureMillis: Interval between checks after a failure; default 30000
  • useHttps: Should the sniffer use HTTPS to check nodes; default false

An example configuration file for creating a Transport Client could like this:

transportClient: true
clusterName: MyClusterName
servers: [ "localhost:9300" ]
settings:
  node.name: MyCustomNodeName

The order of precedence is: transportClient/servers/clusterName > settings > settingsFile, meaning that any setting in settingsFile can be overwritten with settings which in turn get overwritten by the specific settings like clusterName.

Notes about the TransportClient

The TransportClient is deprecated, and you are encouraged to use the RestClient. This has the advantage of not being tied to the specific Elasticsearch version being used, but does require more detailed code for lower-level methods (such as cluster health, retrieve aliases, etc.)

The NodeClient was removed in Elasticsearch 5.x, and it is no longer valid in this connector.

The suggested alternative is to launch a local coordinating node, with whichever plugins you require, and use the Transport or Rest client to communicate with that. The coordinating node should join your cluster.

See Connecting a Client to a Coordinating Only Node

Maven Artifacts

To install using Maven, this github repository can be added to your pom.xml:

<repositories>
  <repository>
    <id>dropwizard-elasticsearch-mvn-repo</id>
    <url>https://raw.github.com/mattflax/dropwizard-elasticsearch6/mvn-repo/</url>
    <snapshots>
      <enabled>true</enabled>
      <updatePolicy>always</updatePolicy>
    </snapshots>
  </repository>
</repositories>

Once that has been done, the project can be added as a regular dependency:

<dependency>
  <groupId>io.dropwizard.modules</groupId>
  <artifactId>dropwizard-elasticsearch6</artifactId>
  <version>1.3.1-0-SNAPSHOT</version>
</dependency>

Support

Please file bug reports and feature requests in GitHub issues.

Acknowledgements

This project was forked from the initial Dropwizard Elasticsearch connector.

Thanks to Alexander Reelsen (@spinscale) for his Dropwizard Blog Sample which sparked the idea for this project.

License

Copyright (c) 2013-2017 Jochen Schalanda

This library is licensed under the Apache License, Version 2.0.

See http://www.apache.org/licenses/LICENSE-2.0.html or the LICENSE file in this repository for the full license text.