what will happen if my cpu usuage stays 100% for 30 mins or so on linux server

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http://stackoverflow.com – I have Amazon Ec2 small instance with 1.7Gb RAM. I have 3 websites running on them. I have the scripts which does the web crawling every day and perform some caluclation. I have not deployed them yet. But i want to know that if those scripts run for 30 mins and processor usage is 100% what will happen to websites. will they stop working or be slow. I am not sure Sites are like 2000 visit per day (HowTos)