Basic solr integration to replace elgg search

2.2.8 2018-04-05 18:48 UTC


Speed up site search by using a dedicated Solr search index

  • Search Entities
  • Search tags (exact match)
  • Search File contents

This plugin follows the structure of the default Elgg search plugin, can be extended using the same search plugin hooks.



  1. Download the plugin and upload it to /mod/elgg_solr, or install with composer composer require arckinteractive/elgg_solr:~2.0

  2. In Admin > Plugins, reorder the elgg_solr plugin to be positioned under search plugin, and enable it

  3. Create a new Solr instance and configure it:

    • Make sure that /<instance>/conf/solrconfig.xml is set to use classic index schema: <schemaFactory class="ClassicIndexSchemaFactory"></schemaFactory>
    • Copy contents of install/schema.xml (or install/schema.solr5.xml for Solr 5+) included in the root of the plugin to /<instance>/conf/schema.xml
      • Copy contents of install/solrconfig.solr5.xml to `//conf/solrconfig.xml if using solr 5
  4. Update elgg_solr plugin settings to point to the new Solr instance

  5. Trigger a reindex from the plugin setting page

  6. Ensure that daily cron is configured and active

Plugin hooks

search, <search_type>

search, <entity_type>

search, <entity_type>:<entity_subtype>

These hooks can be used to modify search criteria

elgg_solr:index, <entity_type>

elgg_solr:index, <entity_type>:<entity_subtype>

elgg_solr:index, annotation

These hooks can be used to customize indexed fields

elgg_solr:can_index, annotation

Allows to add annotations to index by name

elgg_solr:access, entities

Allows plugins to add additional access queries.


Tuning indexed values

Indexed values can be customized using 'elgg_solr:index',<entity_type>' hook:

elgg_register_plugin_hook_handler('elgg_solr:index', 'object', function($hook, $type, $return, $params) {

	$entity = elgg_extract('entity', $params);
	if (!$entity instanceof Event) {

	$return->custom_field_s = $entity->custom_field;
	$return->start_time_i = $entity->start_time;
	return $return;

Adding annotations to index

To add an annotation to the index, add annotation name to the return of the 'elgg_solr:can_index','annotation':

elgg_register_plugin_hook_handler('elgg_solr:can_index', 'annotation', function($hook, $type, $return) {
	$return[] = 'revision';
	return $return;

Indexed values


  • id - guid
  • type - entity type
  • subtype - entity subtype
  • owner_guid - guid of the owner
  • container_guid - guid of the container
  • access_id - access level
  • title - title
  • name - name
  • description - description
  • time_created - timestamp of the creation
  • time_updated_i - timestamp of the last update
  • enabled - is entity enabled
  • tag_<tag_name>_ss - tags for registered tag metadata names
  • has_pic_b - flag indicating that entity has an uploaded icon
  • responses_thread_i - guid of the comment/reply thread root
  • responses_is - guids of comments/replies
  • responses_count_i - total count of comments/replies
  • likes_count_i - total count of likes


In addition to Entity fields:

  • username - username
  • profile_<field_name>_s - profile fields with a single value
  • profile_<field_name>_ss - profile fields with multiple values (tags)
  • groups_is - guids of groups a user is member of
  • groups_count_i - total number of groups a user is a member of
  • friends_is - guids of user's friends
  • friends_count_i - total number of friends
  • last_login_i - timestamp of the last login
  • last_action_i - timestamp of the last activity
  • has_pic_b - flag indicating that user has an avatar


In addition to Entity fields:

  • group_<field_name>_s - profile fields with a single value
  • group_<field_name>_ss - profile fields with multiple values (tags)
  • members_is - guids of group members
  • members_count_i - total number of group members


To index file contents, enable extraction (extract_handler) in plugin settings.

In addition to Entity fields:

  • attr_content - extracted contents
  • simpletype_s - simple type (e.g. image, document etc)
  • mimetype_s - detected mime type (e.g. application/json)
  • originalfilename_s - original name of the uploaded file
  • filesize_i - file size in bytes