CDN Planet

MaxCDN is a very low-end "CDN". If you can buy your account from the website without talking to an account manager, and the plans are as low as $9/month, you should not expect a lot of performance, features, locations, etc.: what you should, however, expect is "cheap"... MaxCDN is appropriately cheap.

To look at something more reasonable: CDNetworks is realistic competition; they are strong in Asia, and were the people I was comparing the pricing to (so they aren't going to be horribly expensive). According to the comparison website you are using, they have almost four times as many edge locations.

http://www.cdnplanet.com/compare/cloudfront/cdnetworks/

Honestly, though, the reality is that the really great CDNs don't even have data on this website (even for CDNetworks I think this data is not accurate: looks like an approximation): the leaders in this space are Akamai and Limelight, and both just show "Not Available" for the number of edge nodes they have.

Even going a little lower on the CDN pecking list, though: Level3, which according to this website you are using is mostly "competitive" with CloudFront (sometimes actually worse) in the regions CloudFront bothers to cover, is clearly covering entire subcontinents where CloudFront has nothing.

The reality is that CloudFront is still trying to grow out a network: they have poor coverage in Europe (which is pretty key), a few nodes in Japan/Singapore, and then next to no coverage anywhere else. Yet, they insist on…

this is a common problem for CDNs, as you can never guarantee the DNS server that's asking for your CNAME is close to the cache servers that you want to deliver your end-user content;

This is the case, and it's a significant problem - especially for people who use Google's DNS server or OpenDNS

There is an experimental, but reasonably widely deployed[1] solution available though.

I'd be surprised if the first CDN cache server a client fetches github content from didn't inspect the end-user IP address from the HTTP session and redirect to a closer / "more optimal" point of presence if one were available;

That's pretty unlikely. The redirect is going to cost more than just serving the data (and of course there is no way to persist that redirect back to the DNS layer, so it will happen for every resource). "Media" CDNs (ie, CDNs optimised for delivery of large files like movies) sometimes work like this though.

HOWEVER, since Fastly/Github is doing Anycast, none of this should affect them.

[1] http://www.cdnplanet.com/blog/which-cdns-support-edns-client-subnet/

Most CDN providers set TCP/IP initial congestion window to boost performance. TCP/IP initial congestion window is how fast TCP/IP first sends the data to the client. TCP/IP has slow start algorithm normally that slowly starts sending data and then its goes faster and faster. I would say most CDN providers have tuned the TCP init congestion window Linux performance setting properly that speeds up the initial sending speed.

One could compare CDN and HTTP server with setting TCP initial window or without.

Linux command to change initcwnd
``sudo ip route change default via 192.168.1.1 dev eth0 proto static initcwnd 10```

For more information about initcwnd see:
* https://blog.imaginea.com/look-at-tcp-initcwnd-cdns/
* https://tma.ifip.org/2018/wp-content/uploads/sites/3/2018/06/tma2018_paper13.pdf
* https://www.cdnplanet.com/blog/tune-tcp-initcwnd-for-optimum-performance/

One problem I've unfortunately run into with alternative DNS providers is that Akamai apparently also uses DNS to steer you to the right part of their CDN, and that the "default" set of servers returned by alternativ DNS providers apparently has abysmal peering with my ISP (not just slightly slower, but positively unusable during peak hours in the evening).

In theory EDNS Client Subnet (ECS) is supposed to work around this problem, but a) according to https://www.cdnplanet.com/blog/which-cdns-support-edns-client-subnet/ Akamai only supports this with Google and OpenDNS and b) alternative DNS providers might not support ECS anyway, whether explicitly for privacy reasons or otherwise…

Which means I'd basically have to set up a custom DNS resolver in order to special-case queries for anything hosted on Akamai's CDN…

This is what I call good marketing!

There's dozens of CDNs to choose from
(https://www.cdnplanet.com/), with the best one obviously being https://fastly.com

However, for most companies it's a wash which CDN to pick.

Unless you're serving media to a large audience the cost is
usually in the low triple digits. And unless you need to serve problematic regions (parts of Asia, Africa), there is barely a difference in performance between most of the contenders.

So what tips the scale for any one of the CDNs?

Well, after this move me and certainly others will definitely
consider Cloudflare more often than previously - out of sheer sympathy.

I made this decision just this week, biggest reason being gzip compression. S3 will only store your file compressed or uncompressed, and you have to do server-side gzip detection to request the proper version, which isn't possible with CloudFront. [1]. You also have to gzip compress locally and upload both versions.

With MaxCDN, I just upload uncompressed, and it will gzip upon request certain text file types (xml, js, css, etc.) [2].

[1] http://blog.kenweiner.com/2009/08/serving-gzipped-javascript-files-from.html

[2] http://www.cdnplanet.com/compare/cloudfront/netdna/