Hello all! I found an issue with overloading server by simple holding down F5 in browser (flooding with refresh) on joomla website. All four CPU cores go immediately to 100% and average load goes to VERY high number. So, the question is - what can be done to prevent these types of abusing from happening? In fact I don't know if this is question for Optimization or Security forum, because I'm not sure if my maybe incorrect mysql server configuration is cause of this overload or it is (as I think) just php/CPU issue. I have csf/lfd installed if that can help to block these types of flood, but also, I think that even without firewall the system should be able to face out this simple load from just one browser. It is VPS running on OpenVZ, 4-core Xeon (Sandy Bridge), full CPU burst available, 2GB ram guaranteed, 4GB in burst. Thanks for any suggestion.