Hi @herlanjafa,

From a problem with the database to just wrong configuration of your wp-config.php file. Luckily, there is a good article just for these occasions here at DigitalOcean - Article.

Please follow up the article and see if you’ll be able to resolve the matter. If you don’t we can follow up on that from there.

Regards,
KDSys

Hello, herlanjafa

Have you checked the MySQL error_log in order to see if the server is running out of memory or if the issue is with to many MySQL connections? As per the tutorial you can run this command in order to check if the server have recently run out of memory:

zgrep -a "allocate memory" /var/log/mysql/error.log*

zgrep will search through log files, including older log files that have been archived as compressed .tar.gz files. We’re searching for lines that contain allocate memory, in any error.log* file in the /var/log/mysql/ directory.

You can always login and check the MySQL error_log when the issue occurs using tail to either check the last 100 entries in the log or monitor the log in real time:

tail -n 100 /var/log/mysql/error.log

and monitor it in real time:

tail -f /var/log/mysql/error.log

Hope that this helps!
Regards,
Alex