Support of Elasticsearch for Node.js

CAST supports Elasticsearch via its com.castsoftware.nodejs extension. Details about how this support is provided for Node.js source code is discussed below.

Supported Client Libraries

Library	Supported
Elasticsearch

Supported Operations

Operation	Methods Supported
Insert	index
Update	update updateByQuery
Select	search msearch explain get mget
Delete	delete deleteByQuery

Objects

Icon	Description
	Node.js Elasticsearch Cluster
	Node.js Elasticsearch Unknown Cluster
	Node.js Elasticsearch Index
	Node.js Elasticsearch Unknown Index

Links

Links are created for transaction and function point needs:

Link type	Source and destination of link	Methods supported
parentLink	Between Elasticsearch Cluster object and Elasticsearch Index object	-
useXLink	Between the caller Node.js Initialization / Function objects and Elasticsearch Index objects	bulk
useInsertLink	Between the caller Node.js Initialization / Function objects and Elasticsearch Index objects	index
useDeleteLink	Between the caller Node.js Initialization / Function objects and Elasticsearch Index objects	delete deleteByQuery
useSelectLink	Between the caller Node.js Initialization / Function objects and Elasticsearch Index objects	search msearch explain get mget
useUpdateLink	Between the caller Node.js Initialization / Function objects and Elasticsearch Index objects	update updateByQuery

What results can you expect?

Some example scenarios are shown below:

Cluster creation

Older version: 16.x

const elasticsearch = require('elasticsearch');

// list of string
let client = new elasticsearch.Client({
    hosts: [
        'https://[username]:[password]@[server]:[port]/',
        'https://[username]:[password]@[server]:[port]/'
    ]
});

// object
let client1 = new elasticsearch.Client({
    host: {
        protocol: 'https',
        host: 'my-site.com',
        port: 80,
        path: '/elasticsearch/'
    }
});

// list of object
let client2 = new elasticsearch.Client({
    hosts: [
        {
            protocol: 'https',
            host: 'box1.server.org',
            port: 56394,
            // these custom values are used below by the selector
            country: 'EU',
            weight: 10
        },
        {
            protocol: 'https',
            host: 'box2.server.org',
            port: 56394,
            // these custom values are used below by the selector
            country: 'US',
            weight: 50
        }
    ]
});

// list of string and object
let client3 = new elasticsearch.Client({
    hosts: [
        'https://[username]:[password]@[server]:[port]/',
        {
            protocol: 'https',
            host: 'my-site.com',
            port: 80,
            path: '/elasticsearch/'
        }
    ]
});

Newer version: >= 5.x

const {Client, errors} = require('@elastic/elasticsearch');

// string
const client = new Client({node: 'http://localhost:9200'});

// URL object
const client2 = new Client({node: new URL('http://127.0.0.1')});

// list of string and URL object
const client3 = new Client({
    nodes: [
        'http://192.168.167.1',
        new URL('google.com')
    ]
});

Insert operation

const response = client.index({
  index: 'myindex',
  type: 'mytype',
  id: '1',
  body: {
    title: 'Test 1',
    tags: ['y', 'z'],
    published: true,
  }
});

Update operation

// string
let response = client.update({
    index: 'indexA',
    type: 'mytype',
    id: '1',
    body: {
        // put the partial document under the `doc` key
        doc: {
            title: 'Updated'
        }
    }
});

// string
response = client.updateByQuery({
        index: 'indexB',
        type: type,
        body: {
            "query": {"match": {"animal": "bear"}},
            "script": {"inline": "ctx._source.color = 'pink'"}
        }
    }, function (err, res) {
        if (err) {
            reportError(err)
        }
        cb(err, res)
    }
);

// list of string
response = client.updateByQuery({
        index: ['indexC', 'indexD'],
        type: type,
        body: {
            "query": {"match": {"animal": "bear"}},
            "script": {"inline": "ctx._source.color = 'pink'"}
        }
    }, function (err, res) {
        if (err) {
            reportError(err)
        }
        cb(err, res)
    }
);

Select operation

let response = client.get({
  index: 'indexA',
  type: 'mytype',
  id: 1
});

Delete operation

client.delete({
    index: 'indexA',
    type: 'mytype',
    id: '1'
});

Bulk

client.bulk({
  body: [
    // action description
    { index:  { _index: 'indexA', _type: 'mytype', _id: 1 } },
     // the document to index
    { title: 'foo' },
    // action description
    { update: { _index: 'indexB', _type: 'mytype', _id: 2 } },
    // the document to update
    { doc: { title: 'foo' } },
    // action description
    { delete: { _index: 'indexC', _type: 'mytype', _id: 3 } },
    // no document needed for this delete
  ]
}, function (err, resp) {
  // ...
});

Known Limitations

For HTML5 Extension version < …
- Identifiers inside a hardcoded list into a dictionary are not resolved, see:

// LIMITATION
a = 'foo'
client.updateByQuery({
    index: ['bar', a] // In this case « a » won't be resolved 
});

// NO LIMITATION
b = ['bar', a];
client.updateByQuery({
    index: b // In this case « a » will be resolved 
});

Operation operating on all indexes (no index argument or index = _all) do not create links
Using client inside object is not supported, see:

// In wrapper.js
const elasticsearch = require('elasticsearch');

var self = {};

self.client = new elasticsearch.Client({
  host: 'client.org'
});


module.exports = self;

//----------------------------------------------------------

// In app.js
const ElasticsearchWrapper = require('./wrapper.js');

ElasticsearchWrapper.client.deleteByQuery({  // -> this call won't be detected as the client is wrapped inside an object
        index: 'some_index',
    },
    function (error, response) {
      if (error)
        sails.log.info("error ", error);
    }
);