This document compares Apache Solr 4.0 and ElasticSearch 0.19. It outlines their main features for searching, indexing, similarities, and provides references for further information. Key differences include ElasticSearch being better for real-time search applications while Solr is more mature. ElasticSearch also supports push queries and has a schema-free structure while Solr has more advanced search features like result grouping.

1. Apache Solr 4.0
vs
ElasticSearch 0.19
- Dikchant Sahi

2. Apache Solr 4.0

Apache Solr is a highly scalable open source
enterprise search platform

Primary features include robust full-text search, hit-
highlighting, faceted search, rich document handling

Is an Apache top level project

Development merged with Apache Lucene

Bigger and more mature user, dev and contributor
community

Solr 4.0 runs on Lucene 4.0

Allows pluggable search/update components

3. ElasticSearch 0.19

Open source, distributed, RESTful search engine

Works better for real time search applications

Supports push queries using percolation

JSON in / JSON out

Schema Free

Multiple document type per schema

Supports distributed queries

Runs on Lucene 3.6

Structured query DSL

4. Searching
Solr ElasticSearch
HTTP query string. Multple response REST API or query string. JSON out.
formats including XML, JSON, CSV.
Analyzers predefined Analyzers can be set during query
Push queries not supported Push queries supported through
percolation
Supports search across shards. Not Supports search across multiple
separate indexes. indexes
Supports result grouping Result grouping not supported
Supports SpellCheck SpellCheck not supported
Supports query elevation Query elevation/campaign not
supported

5. Indexing
Solr ElasticSearch
Single or multiple document per Single document with standard call.
request _bulk endpoint for batch indexing
Multiple format allowed as input JSON in
including XML, JSON, CSV
Supports dataimport for import from No native support for DB read.
DB Plugins available.
Updates require configuration changes Updates require custom work
Flat document structure Supports nested object
Supports deduplication Deduplication not supported

6. Similarities

Both are built of top of Apache Lucene

Both equally scalable

Both provide specialized Java API

Both provide cloud features

Both supports filters, MoreLikeThis

Both let's you control cache

7. References

http://lucene.apache.org/solr/

http://www.elasticsearch.org/

https://github.com/jprante/elasticsearch-river-jdbc

http://blog.sematext.com/2012/09/04/solr-vs-elastic

http://spinscale.github.com/elasticsearch/2012-03-ju

http://solr-vs-elasticsearch.com/