What is the basic unit of application deployment? Two related trends have changed the answer to this question: DevOps Containers For many years, the tasks between engineer and operator were cleanly, if painfully, split: Engineer builds and delivers a package of files to deploy and run Operator deploys and runs those files in a production operating environment In the early years, the package of files consisted of a directory with a ream of paper and instructions.

I have always loved the contrast between companies that are quick and light, focused on doing the right thing, and are nimble in execution and change on the one hand, and those that must plan everything down to the minutest detail before beginning, execute on their plans precisely... and are thrown off balance by change. In my Wall Street days, I worked for two such companies. Both could be defined by "

In one of our earlier discussions about cloud, an astute reader pointed out that one "downside" of public cloud, especially one like AWS, is that they make very few guarantees about your instances. While the system as a whole has service level agreements (SLAs), your particular instance does not. To quote: "If your instances go down you're going to have to deal with it" The underlying assumption, of course, is that you have better control over the level of availability of your particular instances and their underlying hardware, especially scheduled maintenance, when you control the entire environment rather than leaving it to a cloud provider like Amazon or Rackspace.