There is no cloud monopoly either. Customers can choose from AWS, GCP, Azure, and several others.
The problem is not market concentration. There are plenty of options. The problem is customers choosing to put all their eggs in one basket.
Until relatively recently absolutely none, and now almost none of the tooling allows effective multi-cloud or hybrid cloud/private.
Basically the cloud providers work very hard to prevent the commodification of their services with special incompatible service offerings, lock-in, interdependency, deep and opaque APIs for integration, and networks of training and certification that position change as a direct threat to people's job security.
Cloud providers today are basically Microsoft in the 90s.
Much as open source challenged Microsoft, I would say that the world now needs open infrastructure tooling that positions hybrid and multi-cloud as first class infrastructure architectural cases in order to displace established cloud provider hegemony. Even then we will have to fight the hardware and real estate economies of scale available to large established cloud providers.
I wrote some observations about this space based significantly on HN community comments prior to the rise of Docker a few years ago: http://stani.sh/walter/pfcts/ ... click 'original' ... the conclusions still seem timely.
Until relatively recently, the cloud didn't exist.
Depends:
> IBM and other mainframe providers conducted this kind of business in the following two decades [after 1961], often referred to as time-sharing, offering computing power and database storage to banks and other large organizations from their worldwide data centers. To facilitate this business model, mainframe operating systems evolved to include process control facilities, security, and user metering.
[…]
> In 1998, HP set up the Utility Computing Division in Mountain View, CA, assigning former Bell Labs computer scientists to begin work on a computing power plant, incorporating multiple utilities to form a software stack. Services such as "IP billing-on-tap" were marketed. HP introduced the Utility Data Center in 2001. Sun announced the Sun Cloud service to consumers in 2000.
[…]
> In spring 2006 3tera announced its AppLogic service and later that summer Amazon launched Amazon EC2 (Elastic Compute Cloud).
It makes sense that cloud companies are inclined to keep customers from giving money to competitors, but they way they sell it and structure services, reserved instances, and enterprise discounts is such that you basically are putting all of your eggs in one basket.
Nobody got fired for buying IBM, until they did.
One of the selling points of cloud providers is managed services like SQS. If you run a multi-cloud architecture, you either can't use managed services, or have to build abstraction layers on top of them (and only use the features that exist in both cloud providers' versions of the managed service).
If you want to use a managed service that only exists on AWS, then that's obviously incompatible with a fully multi-cloud architecture.
And this is, of course, why they do everything they can do discourage it. Because if you do that, not only are you not reliant on them for availability, you can switch more of your business to the other provider(s) based on current pricing, and they do not want that big time.
If you make the engineering decision to go multicloud for whatever reason those are inherent trade offs you need to be aware of. They have their own agenda of course in addition to any actual fundamental "real" in bulk efficiencies that price reflects.
The DNS is part of the load balancing, they serve different IPs based on location of the DNS query.
Edit: Apparently they do support a CNAME configuration if you pay for one of their business plans. That gives you the option to quickly switch away (if your TTL is low enough) but will impact performance by having to fetch the CNAME every 60 seconds.
But I'm pretty sure they use DNS do other loadbalancing and DDoS mitigations.
For example, if a site is under attack, they can send it to different IP addresses to keep it away from other sites. Or if someone is directly targeting a cloudlflare IP with a DDoS, they can redirect all sites to other IPs and just blackhole that IP.
Shouldn't be too hard to build an abstraction layer that updates them all when you need to make changes.