Setting up Solr

This is out of date as of October 5th, 2013

Overview

If your work touches anything with project listing pages or certain other features, you may require a working Solr index.

All Drupal.org development sites point to the same shared Solr server hosted at stagingsolr.drupal.org, by default with read-only access. This Solr index gets periodically refreshed from a scrubbed version of the index on the live servers. (TODO: HOW OFTEN?)

To flip your server's access from read-only to writable, you need to adjust an option in settings.local.php. The following instructions walk you through that process.

Enabling Solr on your development site

1. Go to Administer >> Reports >> Apache Solr search index (admin/reports/apachesolr) and take note of the current "Number of documents in index." We want that number to go up. :)
2. See who else's development sites are currently able to write to Solr, by running the following from /var/www/dev on devwww.drupal.org:
   

   find . -type f -name 'settings.local.php' -exec grep apachesolr_read_only {} + 

   If any of those values come back as 0 rather than 1, like:

   ./webchick-drupal.redesign.devdrupal.org/htdocs/sites/default/settings.local.php: 'apachesolr_read_only' => 0, // read-only Solr access 

   ...then contact the owner of that sandbox to coordinate with them. Otherwise, each of you will over-write each others' changes, and that's no fun!

3. All coordinated now? Great. In sites/default/settings.local.php, you'll find the custom settings for your particular Drupal.org development site. Among them is the following blurb:
   

   $conf += array( 'apachesolr_read_only' => 1, // read-only Solr access 'apachesolr_host' => 'stagingsolr.drupal.org', 'apachesolr_port' => '8080', 'apachesolr_path' => '/solr', ); 

   Toggle the apachesolr_read_only value to 0 instead.

4. Now, go ahead and create/update/tag content, or do whatever else is needed to populate the Solr index for your development project.
5. drush cron -v
6. Return to Administer >> Reports >> Apache Solr search index (admin/reports/apachesolr) and make sure that the "Number of documents in index." has gone up. If so, you're in business!

Local Solr development

You can also grab a copy of the scrubbed live Solr index and play around with it locally. This is located on util.drupal.org at:

/var/dumps/solr/drupal_redesign_solr_distribution-current.tar.bz2 

A new copy of the index is taken approximately every 24 hours, and is about 1.5 GB in size as of November 2011.