Build the own CDN service

A Content Delivery Network is usually used for static media. Some CDNs are Push and some are Pull, meaning that you either have to Push content to their servers and they replicate it among their own network of servers or they Pull from your site with a map that tells them that cdn.domain.com -> yourdomain.com/media/. Requests for static media are served from the CDN and pulled from the origin (your server) if they are not there.

A Pull CDN can also cache the origin (dynamic pages as well) keeping some functionality of your site alive if the origin server goes down. However, for a very interactive site, that won't be very helpful. A news site serving 5 minute old data is able to utilize a CDN to cache the origin a little better than a social media site where status updates taking 5 minutes to display could make or break you.

A CDN is usually a cache and holds very little intelligence at their edge. These are machines set up strictly to cache content and serve it quickly. While Akamai does support Edge Side Includes, getting them to actually do it is costly and somewhat difficult. Static content is generally what CDNs will cache.

Your mysql data and origin site functionality still exists in one place, but, your static content and possibly your cached pages would be served by the CDN. In order to run your site from multiple locations, you would need to run multiple servers with a 'director' that would send surfers to the closest server. You can do that with host naming, DNS Anycast or a director box. You would still need to run multiple LAMP servers in various data centers. There are hosting providers that can handle multiple location deployments and you can still use a CDN to offload your static content.

DNS by design does not enable having an authoritative copy of all zones, as it utilizes a hierarchical naming system.

The root servers are authoritative for identifying the server responsible for the Top Level Domain (TLD) in question. For example, resolving www.example.net will first query a root server to identify the authoritative nameserver for .net. The .net nameserver will identify the authoritative nameserver for example.net, which will then return the record for www.example.net.

You cannot download a copy of all zones. However, you can run a local caching nameserver. The caching nameserver will provide a local copy of all records resolved, which expire using the Time To Live (TTL) specified for the record. Please keep in mind that my explanation is a simplistic description of the DNS protocol, which can be explored in detail by reading definitions in the Request For Comments.

While NXDOMAIN hijacking can be avoided by running a local cache, keep in mind that all DNS resolution traffic will still be transmitted via your Internet connection unencrypted. Your ISP could potentially monitor that traffic and still see the communication. The contracts you have with your ISP as well as your local laws are going to be your definitive means for establishing how your communications are treated. Your ISP's contracts will include the Terms of Service, Privacy Policies and any additional contracts that you may have with your ISP.

Using encrypted protocols is one of the best methods for insuring your data against eavesdropping during transit. However, even that has no guarantee of anonymity. There are additional protocols out there such as Tor and Freenet, which attempt to introduce anonymity to the Internet, as it was never designed to be truly anonymous.