How to tweak PHP and MYSQL after getting bigger server

Hi all,

We are getting some traffic spikes in recent days due to all this lockdown thing, so we increased the server from 4 cores 8GB to 6 cores 16GB, but it seems it made little difference. How should I tweak PHP and MYSQL or anything else so that it takes better advantage of the extra resources? I can see MYSQL is always on the top CPU usage on htop, so I guess it should be increased to better use the extra RAM, but I am not sure what to change.

We are using still EasyEngine 3.7.5 with FASTCGI only as cache, we tried enabling W3TC just the database and object cache but we saw little to no difference. The server is bogged down at around 200 shoppers. Also, we updated from Woocommerce 3.6 to 4.1 but it seems even slower…

RAM seems to be sitting around 5~6GB of usage even on 100% CPU usage so I guess it is peaked at that, leaving like 9~10GB free to tweak (or less to be conservative if necessary).

I have set php max children to 120, but it gets all taken with this much traffic, I wonder if I should raise ou lower this value (guessing if I lower to 60, would it make this ‘queue’ smaller thus not taking so long to respond) but I am not sure.

Any help is appreciated, thanks in advance