Hello there..
I found this while trying to debug why our application is so slow during concurrent users (about 40) when taking a quiz that renders moodle not usable almost with a very good resource platform
Moodle 3.4.4+, PHP 7.18, MySQL 5.7.21 and redhat enterprise 7.1 64-bit. App and db have their own server.
How do I fix this cache issue? purging the cache does not help.
++ Your cache configuration file is out of date and needs to be refreshed. ++
* line 93 of /cache/locallib.php: call to debugging()
* line 578 of /cache/locallib.php: call to cache_config_writer->config_save()
* line 505 of /cache/locallib.php: call to cache_config_writer->write_definitions_to_cache()
* line 603 of /cache/classes/helper.php: call to cache_config_writer::update_definitions()
* line 1810 of /lib/upgradelib.php: call to cache_helper::update_definitions()
* line 175 of /admin/cli/upgrade.php: call to upgrade_core()