|Stable release||0.90.7 / November 13, 2013|
|Type||Search and index|
|License||Apache License 2.0|
Elasticsearch is a search server based on Lucene. It provides a distributed, multitenant-capable full-text search engine with a RESTful web interface and schema-free JSON documents. Elasticsearch is developed in Java and is released as open source under the terms of the Apache License.
Shay Banon created Compass in 2004. While thinking about the third version of Compass he realized that it would be necessary to rewrite big parts of Compass to "create a scalable search solution". So he created "a solution built from the ground up to be distributed" and used a common interface, JSON over HTTP, suitable for programming languages other than Java as well. Shay Banon released the first version of Elasticsearch in February 2010.
Elasticsearch can be used to search all kinds of documents. It provides a scalable search solution, has near real-time search and support for multitenancy. "ElasticSearch is distributed, which means that indices can be divided into shards and each shard can have zero or more replicas. Each node hosts one or more shards, and acts as a coordinator to delegate operations to the correct shard(s). Rebalancing and routing are done automatically [...]".
It uses Lucene and tries to make all features of it available through the JSON and Java API. It supports facetting and percolating , which can be useful for notifying if new documents match for registered queries.
Another feature is called 'Gateway' and handles the long term persistence of the index- i.e. an index can be recovered from the Gateway in a case of a server crash. Elasticsearch supports real-time GET requests, which makes it suitable as a NoSQL solution, but it lacks distributed transactions.
There are already smaller and some bigger companies using Elasticsearch, including StumbleUpon, Mozilla, Quora, Foursquare, Etsy, SoundCloud, and GitHub. There are also several companies emerging with a focus on providing Elasticsearch as service.
- PyCon 2013 
- What's Next 2011 
- Berlin Buzzwords 2010-2012 
- PHP UK 2011 
- YAPC::EU 2010 
- The Future of Compass
- Initial version of ElasticSearch
- Official Website
- percolate at elasticsearch.org reference
- "elasticsearch Guide: Gateway". elasticsearch. Retrieved April 19, 2013.
- ElasticSearch as database
- No transaction support
- ElasticSearch users
- StumbleUpon uses ElasticSearch
- Why Mozilla uses ElasticSearch
- ElasticSearch helps Mozilla Metrics team
- Full Text Search on Quora
- foursquare now uses Elastic Search
- Oculus: The metric correlation component of Etsy's Kale system
- Architecture behind our new Search and Explore experience
- A Whole New Code Search
- PyCon 2013 - Elasticsearch (Part 1): Indexing and Querying
- Video, InfoQ presentation
- Video, Berlin Buzz 2011
- Berlin Buzz 2011
- Berlin Buzzwords 2010
- Mozilla Metrics at Berlin Buzzwords 2010
- Berlin Buzzwords 2012
- Zmievski, Andrei (25 Feb, 2011). "99 Problems, But The Search Ain't One (PHP UK 2011)". elasticsearch. Retrieved October 6, 2012.
- YAPC::EU 2010