Word of caution about MySQLTuner suggestions ... they are just that ... do not have to implement them all. Some, if tweaked too high, might give deminishing returns.
The biggies:
InnoDB buffer pool / data size - buffer pool should be slightly higher than data.
InnoDB buffer pool instances - # of - 1 per GiG of above.
Did you see any: Total fragmented tables?
Pay attention to:
Maximum reached memory usage
Maximum possible memory usage
Overall possible memory usage with other process is compatible with memory available
Highest usage of available connections
Aborted connections
Name resolution is active: a reverse name resolution is made for each new connection which can reduce performance
In config.php of the moodle, DB host is? If localhost, don't need name resolution because localhost will always be 127.0.0.1 or IPv6 equiv.
Yes, good idea to let DB admin handle!
'SoS', Ken
by Ken Task.