Everyday around 10:53am Moodle will typically slow to a crawl. Occasionally (a few times a month) Moodle will crash altogether. Initially I thought, "Ah! Must be a cron job." However I stopped all cron jobs for 24 hours and saw the same issue. I've watched both machines and the database server seems to never have an issue however the processor usage on the Moodle server skyrockets to 100% right before the server stops responding. When I look at the current processes running on the Moodle server, nothing is using a ton of resources.
- Virtualized with WMware vSphere
- Moodle and Database are on seperate virtual servers
- CentOS 5.6 x64 (both servers)
- Background information:
- Public School (Grades 5-12)
- 2273 students active in past 18 days (1 laptop per student)
- 278 teachers active in past 18 days (1 laptop per teacher)
- Moodle 2.1.2
- MySQL 5.0.77
- PHP 5.3.3
- 65,829,987 db queries in the past 15 days
- Moodle server
-
- 4 virtual CPU's
-
- Intel Xeon Core 2 @ 2.67GHz
- 8GB of RAM
- Database server
-
- 1 virtual CPU
-
- Intel Xeon Core 2 @ 2.67GHz
- 4GB of RAM
I don't have any PHP accelerators installed at the moment. I've read through tons of threads, and tried tweaking some settings here and there like enabling dbsessions but see no improvement. Please tell me I'm overlooking something simple.
Thanks in advance,
Nathan