Hello, we are using Moodle 3.2.1 installed on 64 bit Windows Server 2016 w 4.GB Ram with Dual Intel Xeon E5-2660 processors. We are using PHP 7.1.19 and MySQL 5.7.16. We are using the Edweiser REMUI theme if that makes any difference. We are running a dedicated server for MySQL.
Our Moodle installation runs perfectly in development. We are able to create courses, course content and quizzes with no issues. Developers are able to successfully take the courses with no performance issues.
The issue occurs during testing when 3 or more users simultaneously login to take a course. The system takes 2 minutes just to log in. (we are using LDAP authentication). After they log in and click on a course, it takes anywhere from 30 seconds to three minutes just to load the next page of a course. We ran the Performance Overview and everything is green. We also have opcache enabled.
It is interesting to note that the Windows Performance Monitor shows the CPU utilization is near zero when the system is hung. Almost as if the Moodle server is waiting for something.
I feel that there is fundamentally something wrong with our setup. 4 concurrent users should not bring a system to its knees. We cannot promote this system to production until we resolve the issue.
Does anyone have any suggestions?