When configuring a Docker environment before a big rollout to production, it’s important to understand what “zero downtime deployment” really means and if it is what it claims. This requires an understanding of the intricacies of how a rolling update works.
So let’s look at what “zero downtime deployment” actually means. Most people don’t want to specify and arrange a maintenance window and have to kick people off just to roll out a new version of an application. This is a problem that Docker Enterprise Edition solves by providing an approach referred to as “rolling updates.”