The biggest thing that companies miss when they're building SaaS applications is that the network fucking matters. I'm talking from a internet-connectivity perspective. The view here is that you can take any ol' 'enterprise' ISP and put your servers on it, and you'll be good to go.<p>Unfortunately, no two ISPs are equal, which often times, forces you to purchase from both. TCP implementations of OS's today have been tuned for the late 90s, which requires dives under the hood to tune them for today's TCP.<p>When your application performance is pegged on the network the, most people say just put static content on a CDN - and that works. But for dynamic content, most people think you're screwed. While you can't main any gigantic gains on it, there are a few things you can do for speed: TCP tuning, compression, path optimization, and pipelining.
We disabled Cloudflare after a month because of their awful nLayer routing. We were getting complaints of slow accesses from Telia customers in Europe. Now we're back with SSD Nodes and much happier with SoftLayer's peering and transit connections (they peer directly with Telia).<p>Your mileage may vary.
Most large players in heavy load content ( like live video streaming ) run double failover systems these days. Even if your running systems on S3 piping it through Akamai, you can't guarantee that they won't drop you when your load gets too high. So you have to setup a sister chain going through another origin and cdn.<p>But even at that if you start talking 100k+ clients you can't offload them all at the same time so you end up having to create this custom origin/mid tier distribution system...<p>Very annoying. I'd like to see CDN's being held liable if they go down or drop you entirely.
I trid out CloudFlare for a few months for a couple of my sites. I was primarily interested in their 'no downtime' feature but could never get it to work for me. I ended up swtiching to S3 and CloudFront, paying a little each month but it actually works.
Now I know where those annoying challenge pages come from. Was planning to add CloudFlare to my site but if it comes with those challenge pages, I'd rather pass.