EasyConnect | simple PDO manager to manage database connections | SQL Database library

Hi all

Moodle version: 2.92 (I know, but this installation is in China).

SQL: mysqli, version ???

PHP: ???

I apologise in advance for the possible lack of information I can give in this post.  The Moodle server I am troubleshooting is in China and I live outside of China.  The server is used by foreign teachers, including me, and lately we cannot log into Moodle.  I am an IT teacher, but this is not my speciality.

The Moodle instance is on a server in China, inside a Linux-based virtual machine.  Previously, the situation was:

• If connected to the school network, one could connect to Moodle using http://info.****.***.cn, if outside the school network, one could also connect to Moodle using http://info.****.***.cn.
• At some point, I think Moodle or the server was upgraded to https.
• Then for security reasons, one could only connect to Moodle if on the school network.  To help the foreign teachers, a web-based vpn was set up, as well as a desktop VPN using EasyConnect.  If the web vpn was used outside of the school network, the URL became https://webvpn.***.cn/https/*************/moodle/
• Last week, when a user accessing Moodle inside or outside the school network (no VPN and on a VPN) could not log into Moodle.

What happens if a user connects to Moodle via the web-based VPN, is that the login page is displayed, the user enters their username and password, and clicks "Log in".  The page seems to refresh, showing the same login page.  No error message is shown on the page, nor in Chrome's Developer Tools (Console).

I cannot access the server.  I can communicate with the server administrators in the Chinese school.  They informed me that the virtual server was 100% full, and that may be the issue.  I did some research and found that perhaps the cache or sessions folders may not be able to be cleared from maybe cron jobs because the server is full.  I informed them that they could delete the contents of var/www/moodledata/trashdir and var/www/moodledata/sessions using the commands rm -rf trashdir/* and rm -rf sessions/* respectively.  

The administrator informed me that the moodledata folder is actually in the opt/ folder, and he cleared these folders.  4GB was released.  The server was restarted and we could still not log into Moodle.

I did more research which suggested the config.php file may be configured incorrectly.  He showed me config.php inside the opt/public/moodle folder.  I focussed on the CFG->wwwroot entry.  This read http://info****.***.cn/moodle.  He suggested trying to change it to https://info****.***.cn/moodle.  I suggested he try these configurations:

• http://www.info****.***.cn/moodle
• http://www.info****.***.cn
• http://info****.***.cn
• https://www.info****.***.cn/moodle
• https://www.info****.***.cn
• https://info****.***.cn

I am not certain which configurations he tried, but he certainly tried https://info****.***.cn/moodle, to no effect.

I suggested he delete the files in moodledata/cache and moodledata/localcache.  No effect, except for the fact we now had 16GB of free space now.

He informed me of error logs from nginx.

I asked him to check the permissions of the sessions folder.  He said the permissions were 777.

I asked him to check the admin folder which is usually in html/moodle/admin and edit index.php.  I asked him to comment out the line:

redirect("index.php?sessionstarted=1&lang=$CFG->lang");

and then delete the sessions folder contents again.  He was tired at this point and did not do this.

So I don't know what to do next.  Please understand that the troubleshooting is difficult due to language barriers, not having access to the server, and not being an expert in such systems.  It would be helpful if some error messages or logs could be attained for Moodle specifically.  I am reaching out to this helpful community for any advice, please.

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