In the swarm mode model, each task invokes exactly one container. A task is analogous to a “slot” where the scheduler places a container. Once the container is live, the scheduler recognizes that the task is in a running state. If the container fails health checks or terminates, the task terminates.

What is swarm mode in Docker?

Docker Engine 1.12 introduces swarm mode that enables you to create a cluster of one or more Docker Engines called a swarm. A swarm consists of one or more nodes: physical or virtual machines running Docker Engine 1.12 or later in swarm mode. There are two types of nodes: managers and workers.

What is swarm key?

A swarm key is not an authorization mechanism per-se (although it can be used a very basic one), it’s an additional pre-shared-key encryption for connections which primarily provides isolation from other networks.