Optimize MySQL configuration

When we provisioned the server, there were only 4 gigs of RAM. After the golive, we increased it to 64 Go, but MySQL does not seem to use it. Which is a pity because we had a few peaks of 750+ simultaneous users and the mysql server became a bottleneck at these times, leading to timeouts. Yet the ram was not being used much.

I was wondering how you guys handle mysql optimisation when provisioning the server. It does not seem Trellis does much tinkering with the mysql configuration file, if I read the mariadb role correctly.

Do you have any general advise on how best to optimize the mysql configuration for WordPress ?

For instance, it seems to me reverse name resolution is not useful and can harm performances.

# Skip reverse DNS lookup of clients

Thank you,