DOS attack, prevent server from freezing

About a week ago we encountered a denial of service attack. The attack consisted of 85MB of continous traffic hitting two of our DS3s that we monitor. In doing this, the server went to a stand still and the mysql process was 100% as it was pushing all this data into the fields. The GUI interface stopped responding during this and for some time after the attack. This lead me to a problem of not being able to find what IP Address they were attempting to DOS. We ended up having to call our ISP for them to use their netflow product to tell us this information and having them blackhole that ip address.

Is there a feature in place that will prevent the database from freezing the whole server in instance when there is a huge spike of data? Can this be requested?

Thanks,

Harold