Prerequisite:
- Java 5 or higher

Steps necessary:
- Download Solr PHP client
- Setting up Solr

Download Solr PHP client
------------------------

This module uses an external PHP library for communicating with Solr servers. Go
to [1] and download version r60 of this library. (The older version r22 is also
still supported, but this might change in the future.)

[1] http://code.google.com/p/solr-php-client/downloads/list

Afterwards, unpack this archive to Drupal's libraries folder, so the directory
tree looks like this:

DRUPAL_ROOT/sites/all/libraries/
  |- SolrPhpClient
     |- Apache/
     |- ChangeLog
     ...

The library should then be found by the module.

Note: If you have the Libraries API [2] module installed, you can also place the
library into any other directory recognized by the Libraries API, e.g.
(depending on the module version):
- DRUPAL_ROOT/libraries
- DRUPAL_ROOT/profiles/PROFILE/libraries
- DRUPAL_ROOT/sites/CONF_DIR/libraries

[2] http://drupal.org/project/libraries

Setting up Solr
---------------

In order for this module to work, you will first need to set up a Solr server.
Download the latest stable version of Solr (1.4.1 at the time of this writing)
from [3] and unpack the archive somewhere outside of your web server's document
tree.

[3] http://www.apache.org/dyn/closer.cgi/lucene/solr/

For small websites, using the example application, located in $SOLR/example/,
usually suffices. In any case, you can use it for developing andd testing. The
following instructions will assume you are using the example application,
otherwise you should be able to substitute the corresponding paths.

Before starting Solr create backups of the schema.xml and solrconfig.xml files
that come with Solr (located in Solr's configuration directory,
$SOLR/example/solr/conf/) and copy the two equally named files that are provided
with this module to Solr's configuration directory.
You can then start Solr. For the example application, go to $SOLR/example/ and
issue the following command (assuming Java is correctly installed):

java -jar start.jar

Afterwards, go to [4] in your web browser to ensure Solr is running correctly.

[4] http://localhost:8983/solr/admin/

You can then enable this module and create a new server, using the "Solr search"
service class. Enter the hostname, port and path corresponding to your Solr
server in the appropriate fields. The default values already correspond to the
example application, so you won't have to change the values if you use that.
If you are using HTTP Authentication to protect your Solr server (which is vital
for security on a production site) you also have to provide the appropriate user
and password here.