This really needs to stop. Go to stackexchange.com and you'll find that more than half of the HTTP requests are to cdn.sstatic.net.
Looking up the IP addresses for cdn.sstatic.net returned five entries for me, all owned by CloudFlare. None of the CloudFlare servers that they are using seem to be in that 25 count.
Sure, these are all for static assets, that isn't the point. There are way more than 25 servers being used to serve the StackOverflow sites.
Stack Exchange dont own their CDN. If you really start couting external servers, you would be adding DNS, possible client side proxy servers, client side network infrastructure, etc... these are things that OTHER people do, not SO.
I would say though, CDN doesn't fall in the same category as DNS. Serving static assets off other networks does take a huge load off the SE infrastructure and should probably be mentioned in the article.
It's how many servers you would need to provision to do the same, with the same code base. It's basically the number of directly active servers our code runs on.
Sure, we use a CDN, but not for CPU or I/O load, but to make you find your answers faster.
Sort of true, but static assets are also trivial to serve. What they get by using CloudFlare is getting their assets as close to end users as possible to reduce latency. This isn't a complex problem to solve (for a single site), just a really expensive one that very few single app companies could ever justify solving themselves. I believe Google and Amazon are the only ones with their own significant CDN infrastructure, everyone else outsources it.
This really needs to stop. Go to stackexchange.com and you'll find that more than half of the HTTP requests are to cdn.sstatic.net.
Looking up the IP addresses for cdn.sstatic.net returned five entries for me, all owned by CloudFlare. None of the CloudFlare servers that they are using seem to be in that 25 count.
Sure, these are all for static assets, that isn't the point. There are way more than 25 servers being used to serve the StackOverflow sites.