Glad that adding RAM helped. I don’t think percentage-used is much use as a measure, though. RAM usage is very elastic, because spare RAM will be used as filesystem cache.
The resource you’re aiming to have enough of is memory, and
- memory=RAM+swap
So if adding RAM isn’t preferred, you can usually add swap instead, and that’s usually cheaper.
Adding RAM will increase costs significantly, so if you want to avoid that, one option is to upgrade temporarily to a larger-RAM machine and then migrate back. This costs you some minutes of downtime.