Apache Solr

Solr is a popular, blazingly fast, open source enterprise search platform. Solr offer highly reliable, scalable, error free, distributed indexing, replication and load-balanced querying, automated failover and recovery, centralized configuration and further genuinely creative features. Many of the world's largest internet sites have their searches powered up and navigated through the tools and techniques of Solr. Its advanced full-text search capabilities can be guessed from the fact that Solr enables powerful matching capabilities including phrases, wildcards, joins, grouping and much more across any data type. Optimized for massive volume traffic, Solr is proven at extremely large scales world-wide. Standarized on open interfaces - XML, JSON and HTTP. Solr uses the tools you use to make application building a snap. Comprehensive administration interfaces feature enables Solr to ship with a built-in, responsive administrative user interface to make it easy to control Solr instances. Extensible plugin architecture feature allows Solr to publish many distinct extension points that make it easy to plugin both index and query time plugins. But since it is Apache-licensed open source, the code can be changed whenever needed.

Solr also publishes a lot of metric data via JMX, which means easy, simple monitoring. Faceted search and filtering, geospatial search, highly configurable and user extensible caching, advanced configurable text analysis, security built right in, advanced storage options etc are some of the other myriad of tools and features making this an elaborate data management system.