When deploying a new version of a Docker Swarm service without causing any downtime for users, what specific update strategy is employed?

The specific update strategy employed by Docker Swarm for deploying a new version of a service without causing any downtime for users is called a rolling update. A rolling update works by incrementally replacing old versions of service tasks, which are individual containers, with new versions. When a user initiates a service update, for example, by changing the image tag of a service definition, the Docker Swarm orchestrator begins the update process. Swarm selects a subset of the currently running tasks to update. For each task selected for an update, Swarm first creates a new container running the updated image and configuration. A critical step for ensuring zero downtime involves health checks. These are predefined checks within the service specification that verify if the ....