Apache Solr requires regular restart

Question

I have Solr installed and set up on my Drupal 7 site. Most of the time it works as expected. However, every so often, maybe every other day at least, the search will suddenly stop working and according to the Drupal error log I get:

"0" Status: Request failed: Connection refused.

The Type column says Apache Solr. To fix this, I just restart the Solr service, is there something I can do to prevent this issue from occurring again? I suspect it's some sort of configuration with the Solr that needs adjusting.

I'm kind of new to Solr, so any tips would be appreciated.

Thanks

Answer 1

I ended up reducing the number of documents to be indexed during cron from 200 to 50. That seemed to resolve the issue, as I have not had any Solr outages over the last couple of weeks.

Answer 2

How busy is Solr server? If not very busy, check if you have a firewall between your Drupal and Solr servers. Some firewalls kill the connections if there is no traffic going through.

One way to test would be to access Solr admin interface. If you can, the server itself is fine, only Drupal's connection died.

I am assuming that Solr client library in Drupal tries to maintain a persistent connection. If that's not the case, the above does not apply.