throttle traffic on apache
sudo apt install apache2-utils
sudo apt install libapache2-mod-evasive
vi /etc/apache2/mods-enabled/evasive.conf
service apache restart
edit it and set values as per below or whatever else you like, the time quantities are seconds
DOSSiteInterval 1
DOSBlockingPeriod 10
#DOSLogDir "/var/lock/mod_evasive"