How can we use DOJO from CDN in OpenSocial App?

Which is the best content delivery network for hosting pay-per-view video?

• I am putting together a small site hosted on google app engine (python). The site will feature paid for video tutorials. The problem is hosting and streaming the tutorials from app engine would be prohibitively expensive so I am looking for a good content delivery network. I know that this is quite a crowded space and I've had a look at what other video tutorial sites are doing: http://lynda.com I think they are running from somewhere called http://files2.lynda.com http://TeamTreeHouse.com Seem to be using amazon cloudfront http://Learnable.com seem to use edgecast I am somewhat new to this (only learnt what a CDN was tonight) and have 2 questions: 1) If my video is hosted on a CDN how can I ensure that the videos can only be viewed through my site? i.e. if someone looks through the html markup, finds the link to where the video resides at the CDN they cannot then share the link / access it outside of my site. 2) Are there any favourite CDN's out there. I hear talk of rackspace but I could't find any 'competitors' using it

• Answer:

  1.) A CDN *is* your site. It just put's it as close to all your users as possible, in order to decrease latency. The link your are talking about, will be something like http://yoursite.com/file/xyz or a subdomain / GAE Backend under http://files.yoursite.com/xyz. The CDN then makes sure, this request get's to your app ASAP, and your App decides what to serve to whom. 2.) There are lot's of CDN's and lot's of Cloud-Hosting Services, who as a by product, put your stuff on their CDN (you don't have to worry about anything). Google Appengine, Amazon AWS, Rackspace, Microsoft Azure and Heroku are some of the well known Cloud Hosting providers. Other services, like CloudFlare, provide a CDN, as well as lot's of security. Regarding your main question: The limiting/expensive factors are obiously bandwith and storage, that means, you should have an eye on that. I'd recommend starting with one of the beforementioned providers (don't use GAE if you plan to later move to your own servers, because the (great) technology stack they provide pretty much locks you in), and stop worrying about the distribution. Focus on making your app great, these services will handle the load. If you really need to make a decision about global availability immediately (first of all, wait for answers from more experienced people than me...), choose one of the bigger providers, because they are more likely to have servers close to any point in the world. And please remember, I don't run 100mm$ businesses, I'm speaking out of my experience with mostly GAE.