In the old days, we put images, css / js, woff etc any assets to CDN, so that clients can download somewhere that geographically optimised.
Around end of 2012 – early 2013, new idea comes out like we should CDN everything, so that we can reduce the complex architecture with memcache, page cache cluster (Varnish) or even microccache etc. Just 1 layer cache and having everything to CDN. Like architecture below.
Your website domain name will directly point to CDN with CNAME. And then the CDN will point to your load balancer address or your web server. So it is like a proxy.
When you do create, it will 100% bypass CDN and goes to web server, when u do UPDATE, the CDN will update from web server then invalidate itself, when you do DELETE, the CDN will bypass request to web server and invalidate its cache. When you read, it read from the CDN, not from web server. So the CRUD action can be completed.
You will need your own cache invalidation strategy, like send update to cloudfront / using versioning object or url.
Here is a sample conf of how we bypass some URLs to go to web server, and making Drupal works.
With AWS cloudfront, you can bypass header ORIGIN, so that you can preform CORs actions. Also you can use similar header bypass feature to detect mobile/PC. With such architecture well setup, theoretically, you can have unlimited PV, as your server wont be really hitted. Your bound will be write DB bound only, which is not a concern in most case.
If you don’t want to understand all these, but want to lower your cost and have higher traffic and faster response, contact bootdev at email@example.com ! We can deploy Dynamic CDN to you in minutes no matter you are using AWS or not. We can point our CloudFront account to your server, it can be Azure, Linode, or any bare-meter. It just need to be Drupal, and you can enjoy the best performance ever.