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How do you do Load Testing and Capacity Planning for Web Sites
I've seen tutorials saying they can run decent websites on 64MB RAM (Debian/Lighttpd/PHP/MySQL) however it's not clearly defined how much hits/traffic a "decent" site gets.
Is there a rule of thumb on how much RAM a web server needs? To keep things simple, let's say you're running a site with static content and it's averaging at 100,000 hits per hour (HTML + images combined, no MySQL). How much RAM is the minimum requirement for that?
You need to determine the average page size for your site that is being served. Then determine, on average, how many unique pages are being presented to users at a time. From there, it's simple multiplication.