SearchStax customers have successfully integrated SearchStax Cloud with both Drupal 7 and Drupal 8 websites.
- Drupal 7 works with Solr versions up to 5.4.1, and can be adapted to use Solr 7.x.
- Drupal 8 integrates with more recent versions of Solr. (Our testing used Solr 6.4.2 with Drupal 8.)
In addition, SearchStax recently announced the availability of a Drupal Module that integrates SearchStax Studio running on Apache Solr 8 with a Drupal 8 or 9 environment.
At a deeper level, the version of Solr doesn’t depend on the version of Drupal. Rather it depends on the version of the Drupal Search API Solr module. The Search API Solr 4.2.x supports Solr 3.6 to 8.x. Search API Solr 4.2.x can be installed in Drupal 7, 8, 9, and 10.