The SitePoint PHP blog has posted an introduction to using Elasticsearch in your PHP applications. In it author Wern Ancheta covers some of the basics of this powerful tool and helps you get an example script up and running for testing.
In this tutorial, we’re going to take a look at Elasticsearch and how we can use it in PHP. Elasticsearch is an open-source search server based on Apache Lucene. We can use it to perform super fast full-text and other complex searches. It also includes a REST API which allows us to easily issue requests for creating, deleting, updating and retrieving of data.
He starts by helping you get Elasticsearch itself installed via the apt-get package manager (may slightly differ depending on your OS of choice) and tested with a simple web-based request to the port the server is running on. With the server set up he then moves on to the PHP aspect, helping you get the elasticsearch library installed via Composer and creating a new client instance. He then includes code examples of some of the main operations you'll perform with entries in the Elasticsearch instance: inserting a document, updating a document, deleting and - of course - searching for documents matching certain simple and more complex criteria.