ElasticSearch
ElasticSearch is an open source, RESTful search engine built on top of Apache Lucene and released under an Apache license. It is Java-based and can search and index document files in diverse formats.
ElasticSearch has been compared to Apache Solr and offers several notable features:
- Provides a scalable search solution.
- Performs near-real-time searches.
- Provides support for Multi-tenancy.
- Streamlines backup processes and ensures data integrity.
- An index can be easily recovered in a case of a server crash.
- Uses Javascript Object Notation (JSON) and Java application program interfaces (APIs).
- Automatically indexes JSON documents.
- Indexing uses unique type-level identifiers.
- Each index can have its own settings.
- Searches can be done with Lucene-based querystrings.