Installation

Place the search_api_solr module either directly under the /modules directory at the root of your Drupal installation, or place it under /modules/contrib directory instead, to group all contributed modules together.

Next, run composer update from within the module's root directory in order to install all dependencies the module requires to work properly. Alternatively, you can use the composer_manager [1] module to install dependencies.

You can now visit the /admin/modules page on your site and install the Solr search module.

[1] https://www.drupal.org/project/composer_manager

Solr search

This module provides an implementation of the Search API which uses an Apache Solr search server for indexing and searching. Before enabling or using this module, you'll have to follow the instructions given in INSTALL.txt first.

For more detailed documentation, see the handbook [2].

[2] https://drupal.org/node/1999280

Running the test suite

This module comes with a suite of automated tests. To execute those, you just need to have a (correctly configured) Solr instance running at the following address: http://localhost:8983/solr/d8 (This represents a core named "d8" in a default installation of Solr.)

Supported optional features

All Search API datatypes are supported by using appropriate Solr datatypes for indexing them. By default, "String"/"URI" and "Integer"/"Duration" are defined equivalently. However, through manual configuration of the used schema.xml this can be changed arbitrarily. Using your own Solr extensions is thereby also possible.

The "direct" parse mode for queries will result in the keys being directly used as the query to Solr. For details about Lucene's query syntax, see [3]. There are also some Solr additions to this, listed at [4]. Note however that, by default, this module uses the dismax query handler, so searches like "field:value" won't work with the "direct" mode.

[3] http://lucene.apache.org/java/2_9_1/queryparsersyntax.html [4] http://wiki.apache.org/solr/SolrQuerySyntax

Regarding third-party features, the following are supported:

• search_api_autocomplete Introduced by module: search_api_autocomplete Lets you add autocompletion capabilities to search forms on the site. (See also "Hidden variables" below for Solr-specific customization.)
• search_api_facets Introduced by module: search_api_facetapi Allows you to create facetted searches for dynamically filtering search results.
• search_api_facets_operator_or Introduced by module: search_api_facetapi Allows the creation of OR facets.
• search_api_mlt Introduced by module: search_api_views Lets you display items that are similar to a given one. Use, e.g., to create a "More like this" block for node pages. NOTE: Due to a regression in Solr itself, "More like this" doesn't work with integer and float fields in Solr 4. As a work-around, you can index the fields (or copies of them) as string values. See [5] for details. Also, MLT with date fields isn't currently supported at all for any version.
• search_api_multi Introduced by module: search_api_multi Allows you to search multiple indexes at once, as long as they are on the same server. You can use this to let users simultaneously search all content on the site – nodes, comments, user profiles, etc.
• search_api_spellcheck Introduced by module: search_api_spellcheck Gives the option to display automatic spellchecking for searches.
• search_api_data_type_location Introduced by module: search_api_location Lets you index, filter and sort on location fields. Note, however, that only single-valued fields are currently supported for Solr 3.x, and that the option isn't supported at all in Solr 1.4.
• search_api_grouping Introduced by module: search_api_grouping [6] Lets you group search results based on indexed fields. For further information see the FieldCollapsing documentation in the solr wiki [7].

If you feel some service option is missing, or have other ideas for improving this implementation, please file a feature request in the project's issue queue, at [8].

[5] https://drupal.org/node/2004596 [6] https://drupal.org/sandbox/daspeter/1783280 [7] http://wiki.apache.org/solr/FieldCollapsing [8] https://drupal.org/project/issues/search_api_solr

Specifics

Please consider that, since Solr handles tokenizing, stemming and other preprocessing tasks, activating any preprocessors in a search index' settings is usually not needed or even cumbersome. If you are adding an index to a Solr server you should therefore then disable all processors which handle such classic preprocessing tasks. Enabling the HTML filter can be useful, though, as the default config files included in this module don't handle stripping out HTML tags.

Hidden variables

• search_api_solr.settings.autocomplete_max_occurrences (default: 0.9) By default, keywords that occur in more than 90% of results are ignored for autocomplete suggestions. This setting lets you modify that behaviour by providing your own ratio. Use 1 or greater to use all suggestions.
• search_api_solr.settings.index_prefix (default: '') By default, the index ID in the Solr server is the same as the index's machine name in Drupal. This setting will let you specify a prefix for the index IDs on this Drupal installation. Only use alphanumeric characters and underscores. Since changing the prefix makes the currently indexed data inaccessible, you should change this vairable only when no indexes are currently on any Solr servers.
• search_api_solr.settings.index_prefix_INDEX_ID (default: '') Same as above, but a per-index prefix. Use the index's machine name as INDEX_ID in the variable name. Per-index prefixing is done before the global prefix is added, so the global prefix will come first in the final name: (GLOBAL_PREFIX)(INDEX_PREFIX)(INDEX_ID) The same rules as above apply for setting the prefix.
• search_api_solr.settings.http_get_max_length (default: 4000) The maximum number of bytes that can be handled as an HTTP GET query when HTTP method is AUTO. Typically Solr can handle up to 65355 bytes, but Tomcat and Jetty will error at slightly less than 4096 bytes.
• search_api_solr.settings.cron_action (default: "spellcheck") The Search API Solr Search module can automatically execute some upkeep operations daily during cron runs. This variable determines what particular operation is carried out.
  • spellcheck: The "default" spellcheck dictionary used by Solr will be rebuilt so that spellchecking reflects the latest index state.
  • optimize: An "optimize" operation [9] is executed on the Solr server. As a result of this, all spellcheck dictionaries (that have "buildOnOptimize" set to "true") will be rebuilt, too.
  • none: No action is executed. If an unknown setting is encountered, it is interpreted as "none".
• search_api_solr.settings.site_hash (default: random) A unique hash specific to the local site, created the first time it is needed. Only change this if you want to display another server's results and you know what you are doing. Old indexed items will be lost when the hash is changed (without being automatically deleted from the Solr server!) and all items will have to be reindexed. Should only contain alphanumeric characters.

[9] http://wiki.apache.org/solr/UpdateXmlMessages#A.22commit.22_and_.22optimize.22

Customizing your Solr server

The schema.xml and solrconfig.xml files contain extensive comments on how to add additional features or modify behaviour, e.g., for adding a language- specific stemmer or a stopword list. If you are interested in further customizing your Solr server to your needs, see the Solr wiki at [10] for documentation. When editing the schema.xml and solrconfig.xml files, please only edit the copies in the Solr configuration directory, not directly the ones provided with this module.

[10] http://wiki.apache.org/solr/

You'll have to restart your Solr server after making such changes, for them to take effect.

Developers