solr is running, but search isn't working: "The Solr server of Solr could not be reached."

Question

I am using Search API Solr (Version: 7.x-1.14), and search was working fine but has stopped working. I now see "The Solr server of Solr could not be reached" at admin/config/search/search_api. In the past, when I have gotten this message, it was because solr had stopped running. In this case, solr is running. I have confirmed this with the "bin/solr status" command.

My settings should all be fine, since they have not changed and were working fine before:

Solr Host: localhost
Solr port: 8983
Solr path: /solr/drupal

What could cause Drupal to now be unable to reach solr when no settings have changed and solr is running?

Answer 1

I'm not sure what caused the problem in the first place, but it was ultimately resolved by running solr with a different user. In trying to address the original problem (whatever it was), I ran solr using the wrong user. Once I ran it with my designated "solr" user, Drupal could then reach solr.