Hotel California Effects of Public Clouds

In his The Case for Hybrids blog post Mat Mathews described the Hotel California effect of public clouds as: “One of the most oft mentioned issues with public cloud is the difficulty in getting out.” Once you start relying on cloud provider APIs to provide DNS, load balancing, CDN, content hosting, security groups, and a plethora of other services, it’s impossible to get out.

Interestingly, the side effects of public cloud deployments extend into the realm of application programming, as I was surprised to find out during one of my Expert Express engagements.

I was talking with an engineer who was tasked with setting up networking infrastructure for a private cloud that would allow his company to migrate the workloads from a too-expensive public cloud into a more cost-controllable private environment.

It looked to be an easy engagement focusing on designing the networking infrastructure for maximum scalability – after all, the programmers deploying cloud applications usually know a bit about scale-out architectures and resiliency – and I got a real shock when encountering the stretched subnets needed to support live long-distance VM mobility in a list of requirements.

It turned out that while the programmers understood everything about application resiliency, the redundant database service offered by AWS lulled them into complacency – they never thought about the database redundancy, and because writing database connect strings straight into source code seems to make sense to some people, they got stuck with an application stack relying on a single database instance that had to be constantly nurtured and carefully migrated to another data center during disaster avoidance process (all other virtual machines could be shut down and restarted on the other end, but the database remained an untouchable holy cow).

Fixing the application stack was (as always) out of question, resulting in another case of brownish substance flowing downwards until it creates expensive complexities in the network layer.


  1. Hi Ivan,
    The costs of public cloud resources are falling however, in a race to zero. If you make bad decisions in how you use the public cloud, it's going to cost you. That's no different than bad decisions with a private cloud. I'd be willing to bet this client is using On Demand instances everywhere and not using the 10x cost savings of Spot Instances wherever possible.
    At any rate, I don't see the problem with being locked-in with an industry leader and falling prices. Be it public or private cloud.

  2. you would undoubtedly not be surprised at the number of developers coding database connection strings into the source instead of using proper methods like ODBC. Almost every C.O.T.S. application i've ever encountered is shackled in that way.
  3. You can only successfully replace a service with another service when the new service provides the same capabilities you use from the old. The idea that one service provider is too-expensive has to be based on getting equivalent services from someone else for less. Getting less for less is easy... getting the same for less, not so easy. You have to be sure what you're getting into before selling people on the "I can do it for less" idea. It isn't in any cloud provider's interest to offer exactly what another provider offers, because that just leaves price as the only leverage -- and nobody wins in a price war because eventually the price becomes unsustainable. So they differentiate in service... and as soon as you leverage that difference, you have lock-in on that provider's service.

    There is no magic in Cloud... you're either a professional who recognises their responsibilities in making things work, or you're a spectator in the audience watching the show. There's no room for spectators up on the stage.
  4. "There is no magic in Cloud... " is exactly right. Users have such little comprehension on how the cloud works and with the rampant 'cloudwashing' going on it isn't hard to see why. Cloud has the potential to improve efficiency and productivity whilst cutting costs but it is not the golden goose- you can't take potential to the bank and managers are getting increasingly frustrated when realising this reality. Cloud is not a one size fits all and when company execs realise this then they are better equipped for a migration that would best suit their needs.

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