pratik_asabe
We prefer to keep it at the defaults:
vm.overcommit_memory = 0
vm.swappiness = 60
vm.vfs_cache_pressure = 100
vm.dirty_background_ratio = 10
vm.dirty_ratio = 20
Swap size is set to 4 GB (never larger than this, no matter how much RAM is installed).
We also apply the cgroups limits mentioned above and set max_user_connections=25 in MariaDB. If a user causes trouble, we simply add them to the Owl blacklist and move on. This setup works well for us.