Surviving Digg/Reddit Effect on EC2

I'm trying to understand how many EC2 servers I should start.

I understand the point of AWS is to be able to scale up quickly, but just for cost estimates, how many (approximately) micro ec2 nodes would be needed to run a simple php web app?

Just for the sake of estimating, assume the app is loading CodeIgniter and serving a static page without any database开发者_StackOverflow社区 access.

Any ideas?

It completely depends on the type of site that you have. If it is static web-pages then one server with caching should be fine. Even dynamic pages should be fine if you do caching in the right places.

Depending on how much traffic you get on the sites you can get several hundred to several thousand hits per minute. An EC2 instance should be able to just about manage that (for a mostly static web-page).

I would recommend you not worrying about it. Any spike will at the most happen for a day. If you need to budget, plan for a 100 computers for one day. If you really need all of them, then you have a few hours to build a simple static e-mail collection page and redirect most of your traffic there.