Dev:APISolrSelect

Solr search API

This is the direct access to the deeply-, embedded Apache Solr Server which is used by YaCy to store document metadata and a search index for the schema as defined in /IndexSchema_p.html. The Solr Schema can be retrieved in standard Solr-Syntax from the servlet /api/schema.xml. The Solr interface is very powerful and can be used in the exact same way as described in the Solr Query Syntax. I.e. an example is:

http://localhost:8090/solr/select?q=*:*&defType=edismax&start=0&rows=3&core=collection1

Please see the original Apache Solr documentation for all functionality of that interface. This interface is not only the same, it is identical because it is attached to the Solr Core directly in the same way as the original Solr servlet is attached without usage of solrj.

Extra Feature: Solr Core Selection

You may notice the parameter core=collection1. This is special and it addresses the standard core 'collection1' which is the default if you omit the parameter. The second search core for webgraph descriptions can be retrieved with the parameter core=webgraph.

Extra Feature: Additional Result Writers for Solr

There is another difference to the standard Solr select API since in YaCy we provide some more result writers as a standard component. One of these result writers produce the same output as the [Dev:APIyacysearch|yacysearch.rss and yacysearch.json] standard YaCy search servlet. The result writer names are opensearch and yjson; the yjson format is different from the solr-embedded json result writer because it used the same property names as the opensearch result writer.

That means: the result format of

http://localhost:8090/solr/select?q=text_t:joshua&defType=edismax&start=0&rows=10&core=collection1&wt=opensearch

is identical to

http://localhost:8090/yacysearch.rss?query=joshua

and the result format of

http://localhost:8090/solr/select?q=text_t:joshua&defType=edismax&start=0&rows=10&core=collection1&wt=yjson

is identical to

http://localhost:8090/yacysearch.json?query=joshua

..but in both cases the ranking is different, since the solr search uses a different ranking approach than the YaCy search (which in some depends on solr)

Example Code

All the examples in the [Solrj documentation for the select servlets] apply. You can use Solrj to access YaCy's embedded Solr. In fact, one part of the YaCy peer-to-peer remote search actually uses Solrj to retrieve remote search results from remote YaCy-embedded Solr.