For some days, every time a user of our Moodle opens a task, the use of Apache CPU goes up to 100% and causes the server to collapse (we must restart it every time it passes).
We have the latest version of Moodle (3.6.2), we use Plesk with MySQL and PHP 7.2.
I have checked that we have debugging and theme editor functions disabled, but we do not know what to do. Any ideas? We will be very grateful!
Thanks a lot!
What task?
Sorry, I mean an Assignment activity. This problems happens when you try to open any of them.
We're going to need to know a lot more about your server.
What does "collapse" look like? Can you check the load? Is it using swap.... and so on?
| CPU | Intel(R) Xeon(R) CPU E5620 @ 2.40GHz (1 core(s)) |
| Version | Plesk Onyx v17.8.11_build1708180301.19 os_CentOS 7 |
| OS | CentOS Linux 7.6.1810 (Core) |
| RAM | 2,80GB |
If so, the obvious thing to investigate is a lame file system. Could be database store or the moodledata directory.
The CPU is Xeon E5620 with 1 core? (The Munin graph confirms that.) But E5620 is 4 core 8 thread CPU. How do you explain that?
About Swap: The machine should never swap. It is there for an emergency. The machine has 2 GB RAM. It is possible that this is the problem (or one of them). Study the other Munin graphs like load average and memory usage.
Hi,
For a week (Upgrade from Moodle 3.5.3 to 3.6.2) , we are encountering the same problem : some tasks (for example : editing a course or displaying results in tests) crash the server. Here is a screenshot from my Virtual Machine (Debian 9.3 + Apache 2.4) on VirualBox which is a copy of the production server (3 servers with Debian 9.6 + Nginx).
My system administrators and me have not found the origin of the problem :/
Is it possible to see top on the true production server ... instead of a VirtualBox and clone of production on whatever? Not the same environment.
And this time, do share what's on the top 5 lines of the 'top' output ... one can copy that text and paste it into a text file to post back here.
Example of just above:
top - 03:36:03 up 19 days, 3:32, 1 user, load average: 0.00, 0.01, 0.05
Tasks: 153 total, 2 running, 151 sleeping, 0 stopped, 0 zombie
%Cpu(s): 7.5 us, 2.4 sy, 0.0 ni, 89.9 id, 0.2 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 8003548 total, 705796 free, 1133740 used, 6164012 buff/cache
KiB Swap: 0 total, 0 free, 0 used. 6140116 avail Mem
Oh, yeah ... I would not shut off cron for a couple of days to see what happens ... can predict a back log of task that will be heavy processing on the DB and server will be slower when cron is started again. Uhhhh ... that's kinda the opposite direction desired.
'spirit of sharing', Ken
One other thing to check .... in 3.6.x there is now a path to php-cli in config of Moodle.
Search site admin menu for path.
Typcially, that path is /usr/bin/php but so far in VPS systems in a user jail (public_html) have found on TMD, LiquidWeb, Host-Ed, and now HostGator ... that is NOT path to the php-cli.
A which php might show /usr/bin/php but turns out that was not the php-cli that's needed.
To find that from ssh as root user type: env [ENTER]
Look for that PATH variable in the output of env command.
I cannot tell you what the path would be ... dependent upon config of cPanel or how WHM does things on VPS systems with different vendors.
Also run, find / -name php [ENTER]
you looking for lines that says/shows /some/path/php
Then run all of those paths with /some/path/php -v [ENTER]
If you don't see (php-cli) in the output of -v then it's the wrong PHP ... it's not the php-cli Moodle is seeking to use.
Go to next /some/path/php -v [ENTER]
The one you find with (php-cli) is the path you want to use in paths of Moodle config.
'spirit of sharing', Ken
Hi Marc,
Did you fix the problem? cause I have the same and didn't find a solution.
Thank you
how often do you run cron.php? Turn it off for a few days and see what happens
We run the cron.php manually, once per week.
Thank you
Here is what happen when students logs to their Moodle accounts and to a specific courses.
Moodle keeps loading!
Thank's in advance
@Ramzi Hosni
once a week?
https://docs.moodle.org/36/en/Cron
"IMPORTANT: Do not skip setting up the cron process on your server for your Moodle. Your site will not work properly without it.
It is recommended that the cron is run every minute, as required for asynchronous activity deletion when using the recycle bin."
And what version of Moodle are you running?
'spirit of sharing', Ken
Hi Ken,
We are running Moodle 3.6.1+ (Build: 20190111)
CPU : Intel® Xeon® CPU E5-2680 0@2.70GHz | 12 core
Memory : 24GB
CENTOS 7
PHP Version 7.1.26
APACHE 2.4
Thank you
@Ramzi Hosni
And have you checked the paths ... to php-cli ... in moodle config?
*IF* that variable is set to use the PHP for the web rather than php-cli then Apache would spike ... me thinks.
Initial login by anyone ... even guest ... records activity the largest table in the DB ... that of logs (the who done it). If running anything web services ... like the mobile app ... you'll find multiple entries in that table for just one student logging in or accessing the site.
Settings in moodle for how long to keep data in logs come into play. Running statistics? - for how long?
** EXTREMELY IMPORTANT ** to keep the DB lean and mean. That's the purpose of the cron job.
Now that your server has probably a back log of things to do in the tables, cron will take longer to catch up.
Wouldn't be surprised if you needed to do the cron job via the command line ... script in code/admin/cli/ several times to catch up.
'spirit of sharing', Ken
Hi Ken,
We setup the cron to work every minute on crontab and recreated the course with assignments causing the problem. Now the system seems to be fine.
Thank's for your help.
RAMZI
Hi Ken,
We'v got the following errors when running the cron!
can you please have a look on the attached text file?
Thank you
Try installing Ghostscript, or correct the `pathtogs`.
Thank's a lot
RAMZI
+1 to what Andrew said! Thanks Andrew!
'spirit of sharing', Ken
Thank's Ken