Configuration

The Client constructor accepts a single object as it’s argument, and the following keys can be used to configure that client instance.

var elasticsearch = require('elasticsearch');
var client = new elasticsearch.Client({
  ...
});

Config options

host or hosts

String, String[], Object[] — Specify the hosts that this client will connect to. If sniffing is enabled, or you call client.sniff(), this list will be used as seeds to discover the rest of your cluster.

Default
'http://localhost:9200'

log

String, String[], Object, Object[], Constructor — Unless a constructor is specified, this sets the output settings for the bundled logger. See the section on configuring-logging[logging] for more information.

Default in Node
[{
  type: 'stdio',
  levels: ['error', 'warning']
}]

apiVersion

String — Change the API that they client provides, specify the major version of the Elasticsearch nodes you will be connecting to.

Warning

This default will track the latest version of Elasticsearch, and is only intended to be used durring development. It is highly recommended that you set this parameter in all code that is headed to production.

Default
"0.90"
Options
  • "master"
  • "1.0"
  • "0.90"

sniffOnStart

Boolean — Should the client attempt to detect the rest of the cluster when it is first instantiated?

Default
false

sniffInterval

Number, false — Every n milliseconds, perform a sniff operation and make sure our list of nodes is complete.

Default
false

sniffOnConnectionFault

Boolean — Should the client immediately sniff for a more current list of nodes when a connection dies?

Default
false

maxRetries

Integer — How many times should the client try to connect to other nodes before returning a ConnectionFault error.

Default
3

requestTimeout

Number — Milliseconds before an HTTP request will be aborted and retried. This can also be set per request.

Default
30000

deadTimeout

Number — Milliseconds that a dead connection will wait before attempting to revive itself.

Default
30000

maxSockets

Number — Number of sockets each connection should keep to it’s corresponding node. This will also be the maximum number of concurrent requests that could be made to that node. These sockets are currently kept alive using agentkeepalive.

Default
10

maxKeepAliveTime

Number, false — Milliseconds of inactivity before the socket is destroyed

Default
60000

connectionClass

String, Constructor — Defines the class that will be used to create connections to store in the connection pool. If you are looking to implement additional protocols you should probably start by writing a Connection class that extends the ConnectionAbstract.

Defaults
  • Node: "http"
  • Browser Build: "xhr"
  • Angular Build: "angular"
  • jQuery Build: "jquery"

selector

String, Function — This function will be used to select a connection from the ConnectionPool. It should received a single argument, the list of "active" connections, and return the connection to use. Use this selector to implement special logic for your client such as preferring nodes in a certain rack or data-center.

To make this function asynchronous, accept a second argument which will be the callback to use. The callback should be called Node-style with a possible error like: cb(err, selectedConnection).

Default
"roundRobin"
Options
  • "roundRobin"
  • "random"

defer

Function — Override the way that the client creates promises. If you would rather use any other promise library this is how you’d do that. Elasticsearch.js expects that the defer object has a promise property (which will be returned to promise consumers), as well as resolve and reject methods.

Default
function () {
  return when.defer();
}

nodesToHostCallback

Function - This function will receive the list of nodes returned from the _cluster/nodes API during a sniff operation. The function should return an array of objects which match the specification for the hosts config.

Default
see nodes_to_host.js

Examples

Connect to just a single seed node, and use sniffing to find the rest of the cluster.

var client = new elasticsearch.Client({
  host: 'localhost:9200',
  sniffOnStart: true,
  sniffInterval: 60000,
});

Specify a couple of hosts which use basic auth.

var client = new elasticsearch.Client({
  hosts: [
    'https://user:pass@box1.server.org:9200',
    'https://user:pass@box2.server.org:9200'
  ]
});

Use host objects to define extra properties, and a selector that uses those properties to pick a node.

var client = new elasticsearch.Client({
  hosts: [
    {
      protocol: 'https',
      host: 'box1.server.org',
      port: 56394,
      country: 'EU',
      weight: 10
    },
    {
      protocol: 'https',
      host: 'box2.server.org',
      port: 56394,
      country: 'US',
      weight: 50
    }
  ],
  selector: function (hosts) {
    var myCountry = process.env.COUNTRY;
    // first try to find a node that is in the same country
    var selection = _.find(nodes, function (node) {
      return node.host.country === myCountry;
    });

    if (!selection) {
      // choose the node with the smallest weight.
      selection = _(nodes).sortBy(function (node) {
        return node.host.weight;
      }).first();
    }

    return selection;
  }
});

Use a custom nodesToHostCallback that will direct all of the requests to a proxy and select the node via a query string param. 

var client = new elasticsearch.Client({
  nodesToHostCallback: function (nodes) {
    /*
     * The nodes object will look something like this
     * {
     *   "y-YWd-LITrWXWoCi4r2GlQ": {
     *     name: "Supremor",
     *     transport_address: "inet[/192.168.1.15:9300]",
     *     hostname: "Small-ESBox.infra",
     *     version: "1.0.0",
     *     http_address: "inet[/192.168.1.15:9200]",
     *     attributes: {
     *        custom: "attribute"
     *     }
     *   },
     *   ...
     * }
     */

    return _.transform(nodes, function (nodeList, node, id) {
      var port = node.http_address.match(/:(\d+)/)[1];
      nodeList.push({
        host: 'esproxy.example.com',
        port: 80,
        query: {
          nodeHostname: node.hostname,
          nodePort: port
        }
      });
    }, []);
  }
})