End-users were facing service interruption while taking tests. Error message saying “Gateway Timeout” came in the page. PFA for reference.
Observations from the server at the time of error reporting,
- CPU and RAM consumption were within limit.
- PHP-FPM service were in active running state. Memory usage was above 600MB
- PHP-FPM service restart/reload solved the issue immediately.
- All dependency system services were in running state (httpd and php-fpm).
Error message from /var/log/php-fpm/error.log
WARNING: [pool www] server reached pm.max_children setting (50), consider raising it
Service interruption happened after 6 hours the error message registered in the log.
We are not able to access moodle when this error comes. We are using Proctoring in moodle quiz.
Server spec:
- CPU: 2 core
- RAM: 4 GB
- Moodle Data storage: 2nd local volume
- OS: Centos-8.2
- Web server: Apache-2.4.37
- PHP: 7.2.24
- PHP-FPM: (Same version as PHP)
- DB: Postgresql-10 (Remote DB)
