Hi Antony,
I am constantly getting abuse from azure, amazon, digital ocean cloud.
x.x.x.x is blocked because of many connection and unblock with 'mysqladmin flush-hosts'
Do you mean you do not want ANY connections from those sources? You mention "abuse" which makes me think that these are not legitimate connection attempts and Maria is only blocking them after they have tried NN times and failed. That sounds like you have port 3306 open to the internet, which is generally considered a Very Bad Thing. (As it is for any port you don't need the random internet to connect to) I would suggest you close this port to the internet immediately. If you do need connections from the internet, then adjust your firewall to restrict it to accept connections from them explicitly. Apologies if I'm misinterpreting this, but if the above is true then I also suggest you review your basic computer security.