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: