A list of the extension points exposed by ElasticSearch (as of 0.19.4)

  • Analysis plugins - use different kinds of analyzers
  • River plugins - A river is an external datasource which ES indexes
  • Transport plugins - Different means of exposing ES API, e.g. Thrift, memcached
  • Site plugins - for running various ES-related webapps, like the ES head admin webapp
  • Custom REST endpoint - lets you define a REST action by extending BaseRestHandler.
  • Scripting plugins - providing support for using different scripting languages as search scripts
  • NativeScripts - loosely equivalent to Solr's FunctionQuery. Allows you to return "script fields", custom scores or perform search filtering.

As far as I can tell (from the source), there's no equivalent of Solr's SearchComponent, which allows you to modify the search request processing pipeline in an extremely flexible manner.