Zero-downtime deployments
For some time now I’ve been thinking about all the different approaches that I have seen and heard with the goal of zero-downtime deployment for a horizontally-scaled application that relies on a database or some form of persistent storage. On most of the projects that I have worked on this was not a requirement, although a speedy and automated deployment was preferred. However, other projects were for websites and applications that formed the backbone of a 24/7 company and as such the idea of even a couple of minutes downtime was unacceptable....