# Elasticsearch

The `elasticsearch` library provides a Ruby client and API for [Elasticsearch](http://elasticsearch.com).

Features overview:

* Pluggable logging and tracing
* Pluggable connection selection strategies (round-robin, random, custom)
* Pluggable transport implementation, customizable and extendable
* Pluggable serializer implementation
* Request retries and dead connections handling
* Node reloading (based on cluster state) on errors or on demand
* Consistent API support for the whole Elasticsearch API
* Extensive documentation and examples
* Emphasis on modularity and extendability of both the client and API libraries

(For integration with Ruby models and Rails applications,
see the <https://github.com/elasticsearch/elasticsearch-rails> project.)

## Compatibility

The Elasticsearch client for Ruby is compatible with Ruby 1.9 and higher.

The client's API is compatible with Elasticsearch's API versions from 0.90 till current,
just use a release matching major version of Elasticsearch.

| Ruby          |   | Elasticsearch |
|:-------------:|:-:| :-----------: |
| 0.90          | → | 0.90          |
| 1.x           | → | 1.x           |
| 2.x           | → | 2.x           |
| 5.x           | → | 5.x           |
| 6.x           | → | 6.x           |
| master        | → | master        |

## Installation

Install the package from [Rubygems](https://rubygems.org):

    gem install elasticsearch

To use an unreleased version, either add it to your `Gemfile` for [Bundler](http://gembundler.com):

    gem 'elasticsearch', git: 'git://github.com/elasticsearch/elasticsearch-ruby.git'

or install it from a source code checkout:

    git clone https://github.com/elasticsearch/elasticsearch-ruby.git
    cd elasticsearch-ruby/elasticsearch
    bundle install
    rake install

## Usage

This library is a wrapper for two separate libraries:

* [`elasticsearch-transport`](https://github.com/elasticsearch/elasticsearch-ruby/tree/master/elasticsearch-transport),
  which provides a low-level Ruby client for connecting to an [Elasticsearch](http://elasticsearch.com) cluster
* [`elasticsearch-api`](https://github.com/elasticsearch/elasticsearch-ruby/tree/master/elasticsearch-api),
  which provides a Ruby API for the Elasticsearch RESTful API

Install the `elasticsearch` package and use the API directly:

```ruby
require 'elasticsearch'

client = Elasticsearch::Client.new log: true

client.cluster.health

client.transport.reload_connections!

client.search q: 'test'

# etc.
```

Please refer to the specific library documentation for details:

* **Transport**:
   [[README]](https://github.com/elasticsearch/elasticsearch-ruby/blob/master/elasticsearch-transport/README.md)
   [[Documentation]](http://rubydoc.info/gems/elasticsearch-transport/file/README.markdown)

* **API**:
   [[README]](https://github.com/elasticsearch/elasticsearch-ruby/blob/master/elasticsearch-api/README.md)
   [[Documentation]](http://rubydoc.info/gems/elasticsearch-api/file/README.markdown)

## License

This software is licensed under the Apache 2 license, quoted below.

    Licensed to Elasticsearch B.V. under one or more contributor
    license agreements. See the NOTICE file distributed with
    this work for additional information regarding copyright
    ownership. Elasticsearch B.V. licenses this file to you under
    the Apache License, Version 2.0 (the "License"); you may
    not use this file except in compliance with the License.
    You may obtain a copy of the License at
    
    	http://www.apache.org/licenses/LICENSE-2.0
    
    Unless required by applicable law or agreed to in writing,
    software distributed under the License is distributed on an
    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    KIND, either express or implied.  See the License for the
    specific language governing permissions and limitations
    under the License.