The last couple of months I have been playing around with elasticsearch, an open source, distributed, RESTful search engine built on top of Apache Lucene. To interact with elasticsearch in PHP I have been using a client called Elastica. This was all fun and games until I needed to do actual queries, which is what our users will be doing most of the time. Elastica's documentation does not (yet) say anything about how to search using the client, so I needed to dig through the code to see if I could find some solutions.

He includes a sample mapping structure and shows how to take both a simple, single-term query and turn it into a request and how to make a more complex request with filters, facets, sorting and a few other things thrown in. He also shows how you can manually create a query (define the JSON structure yourself) and push that into the "query builder" for handling.

Elasticsearch is built on top of Lucene and indexes data as JSON documents in a similar way to the way MongoDB stores data. This means as with Mongo that it is schemaless and creates fields on the fly. It is queried over HTTP using queries which are themselves defined in JSON. [...] What I want to do is look at how you can avoid having to deal with issuing JSON queries over HTTP from a Symfony2 app and actually get started using elasticsearch in a very simple way.

He uses the Elastica PHP library to do some of the "heavy lifting" in the three posts so far:

• Symfony2: Integrating elasticsearch
• Symfony2: improving elasticsearch results
• Symfony2: elasticsearch custom analyzers