It’s encouraged that you secure your Solr instance by placing the application on a different file server and behind a firewall. That’s an issue if you are trying to consume data from the Solr instance leveraging AJAX techniques.
Flowchart of a reverse proxy directive that rests on website.com’s httpd.conf file.
www.website.com and Apache Solr live on separate boxes.
A firewall protecting Apache Solr plus the cross-domain issue does not expose the necessary end-point to consume via AJAX.
Depending on your sys admin setups, Solr may not live on a fully qualified domain (ie. http://18.104.22.1689:8983/solr/#/)
An AJAX call to consume the Solr instance’s JSON/XML won’t work cross-domain.