Hello everyone, I hope someone can help us solve our problem with Moodle and Solr.
After successfully trying out Solr and Global search on a local Windows Moodle installation of Moodle, we installed Solr on our Linux server for production, following the corresponding instructions in the Moodle and Solr documentations. Solr is up and running with no problems.
Global search and Solr are also all "green" in the Moodle Search Plugin config.
However, when we search for a term with the global search, we get the "Server error 503 Service Temporarily Unavailable" message.
Funny enough, when we click on the option "Reload" once, twice, three or sometimes even four times, we get the desired results. This also happens when we change the tab, for example, it finds the content without error, then you click on the tab course and the 503 message comes again. After reloading we get the results. We also get the 503 message when we have Solr active and want to configure the Search plugin in Moodle.
Plesk shows the messages: "AH01067: Failed to read FastCGI header" and "(104)Connection reset by peer: AH01075: Error dispatching request to : , referer: https://..." we increased the FastCGI limits and restarted Apache as suggested by Plesk... but that did not help... we also checked the ulimits and increased them to 65000 as suggested by Solr, but it also did not help. The extension .so is there everywhere where it should be, solr appears in the moodle phpinfo() too... we have run out of ideas.
If we use the Simple search everything works fine and we face no errors at all, but we are using Solr's functionality for spellchecking and suggester and we would like to continue using it. The rest of the platform and plugins also work without a problem.
Our current server settings are: Moodle 3.10.2, PHP 7.4.21, Linux Ubuntu 20.04, Solr 8.9.0, Solr extension 2.5.1, Plesk 18.0.36, Java 11.0.11 64-Bit
I hope somebody can help us with this issue. Thank you very much!